Thunder Scientific 2500, 2500ST User guide

OPERATION AND MAINTENANCE MANUAL

BENCHTOP TWO-PRESSURE

HUMIDITY GENERATOR

SERIES 2500

®

MADE IN USA

SERIES 2500

BENCHTOP TWO-PRESSURE

HUMIDITY GENERATOR

OPERATION AND

MAINTENANCE MANUAL

Copyright © 1991-2018

THUNDER SCIENTIFIC CORPORATION

ALBUQUERQUE, NEW MEXICO 87123-3198

Tel: [phone]  FAX: [phone]

Document Edition 18  January 2018
Firmware Version 2.14

THUNDER SCIENTIFIC® is the registered trademark of Thunder Scientific Corporation.
All the information provided in this document is correct and true at the time of publication.
Thunder Scientific Corporation reserves the right to change any technical data without notice.

623 WYOMING BLVD. SE

www.thunderscientific.com

Printed 2018

e-mail: [e-mail]

Model 2500 Two-Pressure Two-Temperature Humidity Generator

i

TABLE OF CONTENTS

Section 1 - GENERAL INFORMATION

List of Illustrations
List of Reference Drawings
Warranty

1.1 INTRODUCTION ---------------------------------------------------------------- 1-1

1.2 PRINCIPLE OF OPERATION ------------------------------------------------- 1-1

1.2.1 General Description --------------------------------------------------------- 1-1

1.2.2 RH Formula For Ideal Gas ------------------------------------------------- 1-2

1.2.3 RH Formula For Air -------------------------------------------------------- 1-4

1.2.4 Pressure Ratio --------------------------------------------------------------- 1-5

1.2.5 Effective Degree Of Saturation ------------------------------------------- 1-5

1.2.6 Enhancement Factor Ratio ------------------------------------------------- 1-6

1.3 SPECIFICATIONS --------------------------------------------------------------- 1-7

1.3.1 Facility Requirements ------------------------------------------------------ 1-7

1.3.2 Environmental --------------------------------------------------------------- 1-7

1.4 COMPUTER CONTROL SYSTEM ------------------------------------------ 1-8

1.4.1 General Description --------------------------------------------------------- 1-8

1.4.2 Central Processing Unit (STD-CPU) ------------------------------------- 1-9

1.4.3 Liquid Crystal Display (LCD) --------------------------------------------- 1-9

1.4.4 Liquid Crystal Display Driver (STD-LCD) ----------------------------- 1-9

1.4.5 Keypad ------------------------------------------------------------------------ 1-9

1.4.6 Memory Card (STD-MEM) ----------------------------------------------- 1-9

1.4.7 Analog to Digital Converter (STD-A/D) -------------------------------- 1-9

1.5 ELECTRICAL ------------------------------------------------------------------- 1-10

1.5.1 AC Power Distribution ---------------------------------------------------- 1-10

1.5.2 Power Supply 24 VAC ---------------------------------------------------- 1-10

1.5.3 Power Supply (STD-PS) -------------------------------------------------- 1-10

1.5.4 Analog Inputs (STD-A/D) ------------------------------------------------ 1-11

1.5.4.1 Temperature Measurement ------------------------------------------ 1-11

1.5.4.2 Mass Flow Transducer (T1) ----------------------------------------- 1-11

1.5.4.3 50 PSIA Pressure Transducer (T2) --------------------------------- 1-11

1.5.4.4 150 PSIA Pressure Transducer (T3) ------------------------------- 1-12

1.5.5 Control Logic --------------------------------------------------------------- 1-12

1.5.5.1 Air Supply Solenoid Valve (SOL1) -------------------------------- 1-12

1.5.5.2 Refrigerant Solenoid Valve (SOL2) ------------------------------- 1-12

1.5.5.3 Pressure Bleed Solenoid Valve (SOL3) --------------------------- 1-12

1.5.5.4 Pressure Select Solenoid Valve (SOL5)--------------------------- 1-13

1.5.5.5 Heat Transfer Fluid Heater (H3) ----------------------------------- 1-13

1.5.5.6 Presaturator Heaters (H1 & H2) ------------------------------------ 1-13

1.5.5.7 Expansion Valve Heaters (H4 & H5) ------------------------------ 1-13

1.5.5.8 Fluid Circulation Pump (FP1) -------------------------------------- 1-13

1.5.5.9 Refrigeration Compressor (C1) ------------------------------------- 1-14

1.5.5.10 Flow Valve (V1) - Actuation --------------------------------------------- 1-14

1.5.5.11 Expansion Valve (V2) - Actuation -------------------------------------- 1-14

1.5.5.12 Reservoir Liquid Level Transducer (LL1) ------------------------------ 1-14

1.5.5.13 Presaturator Liquid Level Transducer (LL2) --------------------------- 1-15

1.5.5.14 Console Fan (CF1) --------------------------------------------------------- 1-15

ii

TABLE OF CONTENTS CONTINUED

1.6 PNEUMATIC SYSTEM ------------------------------------------------------- 1-16

1.6.1 General Description ------------------------------------------------------- 1-16

1.6.2 Presaturator ----------------------------------------------------------------- 1-17

1.6.3 Saturator--------------------------------------------------------------------- 1-17

1.6.4 Expansion Valve ----------------------------------------------------------- 1-17

1.6.5 Reservoir -------------------------------------------------------------------- 1-17

1.7 HEAT TRANSFER FLUID SYSTEM --------------------------------------- 1-19

1.7.1 General Description ------------------------------------------------------- 1-19

1.7.2 Fluid Heating --------------------------------------------------------------- 1-20

1.7.3 Fluid Refrigeration -------------------------------------------------------- 1-20

Section 2 – INSTALLATION

2.1 GENERAL ------------------------------------------------------------------------- 2-1

2.2 FACILITIES REQUIRED ------------------------------------------------------- 2-1

2.2.1 Bench / Floor Space --------------------------------------------------------- 2-1

2.2.2 Power -------------------------------------------------------------------------- 2-1

2.2.3 Air Supply (if used without pneumatic cart) ----------------------------- 2-2

2.2.4 Distilled Water Supply ------------------------------------------------------ 2-2

2.3 PREPARATION ------------------------------------------------------------------ 2-2

2.3.1 Chamber Fluid Filling ------------------------------------------------------- 2-2

2.3.1.1 Chamber Fluid Filling Procedure ------------------------------------ 2-2

2.3.2 Positioning and Connections ----------------------------------------------- 2-3

2.3.2.1 Pneumatic Cart --------------------------------------------------------- 2-3

2.3.2.2 Bench Space ----------------------------------------------------------- 2-4

2.3.2.3 Power ------------------------------------------------------------------- 2-4

2.3.2.4 Air Supply --------------------------------------------------------------- 2-5

Section 3 – OPERATION

3.1 GENERAL ------------------------------------------------------------------------- 3-1

3.2 STANDARD OPERATING PROCEDURES -------------------------------- 3-1

3.2.1 Power-Up --------------------------------------------------------------------- 3-1

3.2.2 Control/Display Screen ----------------------------------------------------- 3-1

3.2.2.1 Changing the Display Contrast -------------------------------------------- 3-3

3.2.3 Changing Setpoints ---------------------------------------------------------- 3-3

3.2.4 Changing Units --------------------------------------------------------------- 3-5

3.2.5 Control Modes --------------------------------------------------------------- 3-5

3.2.6 Run/Stop ---------------------------------------------------------------------- 3-6

3.2.7 Printer (optional) ------------------------------------------------------------- 3-7

3.2.8 Power-Off --------------------------------------------------------------------- 3-7

3.2.8.1 Maintenance Power-Off ----------------------------------------------- 3-8

3.2.9 Filling the Reservoir --------------------------------------------------------- 3-8

3.3 EDITING SYSTEM COEFFICIENTS AND PARAMETERS ------------ 3-9

3.3.1 Edit Mode --------------------------------------------------------------------- 3-9

3.3.2 Coefficients and Parameters---------------------------------------------- 3-11

iii

TABLE OF CONTENTS CONTINUED

3.3.2.1 Temperature Coefficients ------------------------------------------- 3-11

3.3.2.2 Reference Resistor Coefficients ------------------------------------ 3-12

3.3.2.3 Pressure Coefficients ------------------------------------------------- 3-12

3.3.2.4 Flow Coefficients ----------------------------------------------------- 3-13

3.3.2.5 Console Port Parameters -------------------------------------------- 3-14

3.3.2.6 Printer Port Parameters ---------------------------------------------- 3-15

3.3.2.7 Time and Date -------------------------------------------------------- 3-15

Section 4 - CALIBRATION AND MAINTENANCE

4.1 GENERAL ------------------------------------------------------------------------ 4-1

4.2 CALIBRATION ------------------------------------------------------------------ 4-1

4.2.1 A/D Board (STD-A/D) ----------------------------------------------------- 4-2

4.2.2 Temperature Calibration --------------------------------------------------- 4-2

4.2.2.1 Temperature Calibration Procedure --------------------------------- 4-3

4.2.3 Pressure Transducer Calibration ------------------------------------------ 4-7

4.2.3.1 Pressure Calibration Procedure -------------------------------------- 4-7

4.2.4 Flow Transducer Calibration --------------------------------------------- 4-11

4.2.4.1 Flow Calibration Procedure ----------------------------------------- 4-11

4.2.5 Printing the Calibration Report ------------------------------------------ 4-14

4.3 ROUTINE MAINTENANCE -------------------------------------------------- 4-17

4.3.1 Console Intake: Monthly -------------------------------------------------- 4-17

4.3.2 Chamber Fluid Level: Yearly--------------------------------------------- 4-17

4.3.3 Pre-saturator Drain: Yearly ----------------------------------------------- 4-17

4.3.4 Mobile Pneumatic Cart: Daily -------------------------------------------- 4-17

4.4 ERROR CODES and TROUBLESHOOTING ------------------------------ 4-18

Section 5 - PARTS LISTS

5.1 COMPLETE SYSTEM COMPONENTS ------------------------------------- 5-1

5.2 PNEUMATIC CART ------------------------------------------------------------ 5-3

5.3 AIR BOX ELECTRICAL ------------------------------------------------------- 5-3

5.4 OPTION INDICATORS --------------------------------------------------------- 5-3

iv

LIST OF ILLUSTRATIONS

FIGURE TITLE PAGE

1-1 Two Pressure Elemental Schematic ---------------------------------- 1-2
1-2 STD Bus Diagram ------------------------------------------------------- 1-8
1-3 Pneumatic System ----------------------------------------------------- 1-16
1-4 Heat Transfer Fluid System ------------------------------------------ 1-19
1-5 Refrigeration System ------------------------------------------------- 1-20
2-1 Mechanical / Utility ----------------------------------------------------- 2-1
2-2 Chamber Fluid Fill Port Location ------------------------------------- 2-3
2-3 Generator / Cart Mechanical ------------------------------------------- 2-3
2-4 Pneumatic Cart w/Air Compressor Sound Enclosure -------------- 2-4
2-5 Pneumatic Cart w/o Air Compressor --------------------------------- 2-5

LIST OF REFERENCE DRAWINGS

DRAWING # DRAWING TITLE

91D25901 -------------------------Layout, Utility / Mechanical
91D25902 -------------------------Probe Location
91D25903 -------------------------Circuit Card and Component Location
91D25904 -------------------------Electrical Sub Panel Layout
91D25905 -------------------------Terminal Layout
91S25906 --------------------------AC / DC Power
91S25907 --------------------------Solid State Relay Module Board
91S25908 --------------------------Compressor / Heater Schematic
91S25909 --------------------------Liquid Level / Speaker Schematic
91S25910 --------------------------Flow Valve (V1) Schematic
91S25911 --------------------------Expansion Valve (V2) Schematic
91S25912 --------------------------Temperature Probe / Transducer Schematic
91D25913 -------------------------STD Bus Diagram
91S25914 --------------------------Display Block Diagram
91D25915 -------------------------RS-232C Console / Printer
91S25916 --------------------------Pneumatic System
91S25917 --------------------------Heat Transfer Fluid System
91S25918 --------------------------Refrigeration System
98D25919 -------------------------Layout, Compressor Enclosure w/Cart
91S25921 --------------------------Schematic, Cart - Pneumatic System
97D25924 -------------------------Instructions, Chamber Fluid Filling
97D25926 -------------------------Cart Mechanical Dimensions R Model
08S25942 --------------------------2500 Fuse Upgrade Schematic
ACS2031 --------------------------Schematic, ACS Twin Electrical

WARRANTY

Thunder Scientific Corporation (TSC) warrants, to the Buyer, the
Product manufactured by TSC to be free of defects in material and
workmanship under normal use and service and to be free from
inadequate mechanical design when operated within the specified
design limitations for a period of twelve months from date of
acceptance. TSC's obligation under this warranty shall be limited
to the following: the Product is returned to TSC with transportation
charges prepaid and that TSC's examination reveals the Product to
be defective. TSC, at its option, shall either refund to the Buyer
the purchase price of the product or repair or replace at TSC's
plant, any part or parts of the Product which is or are defective.
This warranty shall not apply to any Product which has been
maintained, handled, stored, repaired or altered in any manner, or
by anyone other than an authorized TSC representative, so as to
affect adversely such Product or which has been subject to
improper installation, misuse, negligence, accident or corrosion.
THIS WARRANTY IS EXCLUSIVE AND IN LIEU OF ANY
WARRANTY OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE OR ANY OTHER WARRANTY,
WHETHER EXPRESS OR IMPLIED, AND ALL OTHER
LIABILITIES AND OBLIGATIONS ON THE PART OF TSC;
TSC SHALL NOT BE LIABLE FOR ANY OTHER CLAIMS OR
DAMAGES, EITHER DIRECT OR CONSEQUENTIAL,
ARISING DIRECTLY OR INDIRECTLY OUT OF SUPPLYING
THE PRODUCT. All warranties, express or implied, with respect
to any device or component not manufactured by TSC but
incorporated into its Product are the responsibility of the original
manufacturer and shall not affect or apply to TSC.

Thunder Scientific®

PROPYLENE GLYCOL 3 bottles for the R, 4 bottles for the ST

Corporation

2500 Item Check List

1. Certificate of Calibration (In Manual)

2. Operation and Maintenance Manual

3. HumiCalc® with Uncertainty Software Download

4. 2500 ControLog® Software Download

5. Chamber Insulation Foam

6. Chamber Port Foam Plug

7. Power Cable

8. Torx Driver with Screws

9. Reservoir Fluid Funnel

10. Chamber Fill Funnel

11. Elbow, ¼ Flare x ¼ MPT Brass

12. Communication Cables (Printer & Computer)

13. Chamber Fluid

1. Optional Equipment – Air compressor power cable

2. ACS2520 – Air Compressor System Manual

3. Air Hose – On Air Box

Thunder Scientific Corporation Web: www.thunderscientific.com

623 Wyoming Blvd. SE E-mail: [e-mail]
Albuquerque, NM 87123 Phone: [phone]

Suomi

English

Tämä tuote noudattaa WEEE-direktiivin (2002/96/EY)
merkintävaatimuksia. Kiinnitetty etiketti osoittaa, että tätä
sähkö-/elektroniikkalaitetta ei saa hävittää kotitalousjätteissä.

Tuoteluokka: Viitaten WEEE-direktiivin liitteessä I mainittuihin
laitteisiin, tämä tuote on luokiteltu luokan 9 “Tarkkailu- ja
ohjauslaitteet” -tuotteeksi.

Ei saa heittää kotitalousjätteiden mukana!

Palauta tarpeettomat tuotteet ottamalla yhteyttä valmistajan
websivustoon, joka mainitaan tuotteessa tai paikalliseen
myyntitoimistoon tai jakelijaan.

Dansk

Dette produkt er i overensstemmelse med kravene om afmærkning
i WEEE-direktivet (2002/96/EC). Det påhæftede mærkat angiver,
at du ikke må bortskaffe dette elektriske/elektroniske produkt via
husholdningsaffald.

Produktkategori: Med reference til kravene i WEEE-direktivets
bilag I klassificeres dette produkt som et produkt til “overvågning
og kontrolinstrumentering” i kategori 9.

MÂ ikke bortskaffes via husholdningsaffald!

Hvis du vil returnere uønskede produkter, skal du besøge
producentens websted, som vises på produktet, eller den lokale
forhandler eller distributør.

This product complies with the WEEE Directive (2002/96/EC) marking
requirements. The affixed label indicates that you must not discard
this electrical/electronic product in domestic household waste.

Product Category: With reference to the equipment types in the
WEEE Directive Annex I, this product is classed as category 9
“Monitoring and Control Instrumentation” product.

Do not dispose in domestic household waste!

To return unwanted products, contact the manufacturer’s web site
shown on the product or your local sales office or distributor.

Français

Ce produit est conforme aux normes de marquage de la directive
DEEE (2002/96/CE). La présence de cette étiquette indique que
cet appareil électrique/électronique ne doit pas être mis au rebut
avec les déchets ménagers.

Catégorie de EEE : Cet appareil est classé comme catégorie 9 parmi
les « instruments de surveillance et de contrôle » en référence aux
types d’équipements mentionnés dans l’Annexe I de la directive DEEE.

Ne pas éliminer avec les autres déchets ménagers !

Pour renvoyer les produits indésirables, contacter le site Web du
fabricant mentionné sur le produit, ou son distributeur ou bureau de
ventes local.

Español

Este producto cumple la Directiva WEEE (2002/96/EC) sobre
requisitos de las marcas. La etiqueta que lleva pegada indica
que no debe desechar este producto eléctrico o electrónico con
los residuos domésticos.

Categoría del producto: con referencia a los tipos de equipo
del anexo I de la Directiva WEEE, este producto está clasificado
como categoría 9 de “Instrumentación de supervisión y control”.

¡No lo deseche con los residuos domésticos!

Para devolver productos que no desee, póngase en contacto con
el sitio Web del fabricante mostrado en el producto, o con la oficina
de ventas o distribuidor local.

PN 2566073, 1/2006

Deutsch

Nederlands

Dieses Produkt stimmt mit den Kennzeichnungsanforderungen
der WEEE-Richtlinie (2002/96/EC) überein. Das angebrachte
Etikett weist darauf hin, dass dieses elektrische/elektronische
Produkt nicht in Hausmüll entsorgt werden darf.

Produktkategorie: In Bezug auf die Gerätetypen in Anhang
I der WEEE-Richtlinie ist dieses Produkt als Kategorie 9
“Überwachungs- und Kontrollinstrument” klassifiziert.

Nicht in Hausmüll entsorgen!

Zur Rückgabe von unerwünschten Produkten die auf dem
Produkt angegebene Website des Herstellers oder die zuständige
Verkaufsstelle bzw. den zuständigen Fachhändler konsultieren.

Italiano

Questo prodotto risponde ai requisiti sull’etichettatura stabiliti
nella Direttiva RAEE (2002/96/CE). Il simbolo apposto indica che
non si deve gettare questo prodotto elettrico o elettronico in un
contenitore per rifiuti domestici.

Categoria del prodotto: con riferimento ai tipi di apparecchiature
elencate nell’Allegato 1 della Direttiva RAEE, questo prodotto
rientra nella categoria 9 “Strumenti di monitoraggio e di controllo”.

Non gettare in un contenitore per rifiuti domestici.

Per restituire prodotti non desiderati, visitare il sito Web del
produttore riportato sul prodotto o rivolgersi al distributore o
all’ufficio vendite locale.

Dit product voldoet aan de merktekenvereisten van de AEEA­richtlijn (2002/96/EG). Het aangebrachte merkteken duidt erop dat
dit elektrische/elektronische product niet met het huishoudelijk
afval mag worden afgevoerd.

Productcategorie: Met betrekking tot de apparatuurcategorieën
van bijlage I van de AEEA-richtlijn, valt dit product onder categorie
9 ‘meet- en controle-instrumenten’.

Niet afvoeren met huishoudelijk afval!

Om ongewenste producten te retourneren, neemt u contact op
met de website van de fabrikant die op het product staat vermeld,
of met uw plaatselijke verkoopkantoor of distributeur.

Svenska

Denna produkt uppfyller märkningskraven enligt WEEE Directive
(2002/96/EC). Märkningsetiketten anger att du inte får kassera denna
elektriska/elektroniska produkt tillsammans med vanliga hushållssopor.

Produktkategori: Med hänvisning till utrustningstyperna i
WEEE Directive Annex I, är denna produkt klassad som kategori 9
“Monitoring and Control Instrumentation” (Instrument för
övervakning och styrning).

Får ej kasseras tillsammans med vanliga hushållssopor!

Returnera ej önskvärda produkter genom att gå till tillverkarens
webbplats, vilken anges på produkten, eller till det lokala
försäljningskontoret eller distributören.

Português

Este produto está em conformidade com as exigências de rotulagem
da Directiva WEEE (2002/96/EC). O rótulo afixado indica que o
utilizador não deve deitar este produto eléctrico/electrónico fora
juntamente com o lixo doméstico.

Categoria do produto: No que se refere aos tipos de equipamento lis­tados no Anexo I da Directiva WEEE, este produto está classificado como
produto da categoria 9, “Instrumentação de monitorização e controlo”.

Não deite fora juntamente com o lixo doméstico!

Para devolver produtos indesejados, contacte o fabricante através do
Website constante do produto ou contacte o seu representante de
vendas ou distribuidor local.

Norsk

Dette produktet oppfyller bestemmelsene ifølge WEEE-direktiv
(2002/96/EC) med krav til merking. Påsatt merke viser at det ikke
er tillatt å kassere dette elektriske/elektroniske produktet sammen
med husholdningsavfall.

Produktkategori: På grunnlag av utstyrstypene i WEEE­direktivet, vedlegg I, er dette produktet klassifisert i kategori 9,
“Instrumentering for overvåking og kontroll”.

Må ikke kastes sammen med husholdningsavfall!

Ved behov for returforsendelse av uønskede produkter må du gå
til produsentens nettside som er angitt på produktet, eller du må
kontakte det lokale salgskontoret eller den lokale forhandleren.

Section 1

GENERAL INFORMATION

1.1 INTRODUCTION

The Model 2500 Benchtop Humidity Generator is a self contained facility capable of
producing known humidity values using the fundamental principle of the "two pressure"
generator developed by NIST. This system is capable of continuously supplying accurately
known humidity values for instrument calibration, evaluation and verification.

The 2500 operates using an on board computer and control system to perform calculation and
control functions. The Computer Control System utilizes a multifunction STD Bus CPU in
conjunction with other STD Bus peripheral cards for control and is incorporated into the
benchtop humidity generator. Peripheral equipment, such as a printer or computer, may be
connected using the bi-directional RS-232C interfaces.

Humidity and temperature setpoint values are input by the operator from the front panel
keypad. Visual indications of system status are displayed in real time on the Liquid Crystal
Display. The automatic features of this system allow the 2500 to generate humidity and
temperature setpoints completely unattended. This automated approach frees the operating
technician from the task of system monitoring and adjustments, allowing him time to perform
other vital tasks.

1.2 PRINCIPLE OF OPERATION

1.2.1 General Description

Operation of the 2500 humidity generator is based on the two-pressure method of producing
known atmospheres of relative humidity and assumes that the water vapor pressure remains a
fraction of the total pressure, known as Dalton's Law of Partial Pressure. Dalton's Law states
that the pressure exerted by a mixture of gases in a given volume at some temperature is
equal to the sum of the pressures which would be exerted by each individual gas if it alone
occupied the volume at the same temperature.

The two pressure method (shown in elemental schematic form in figure 1-1) involves
saturating air, or some other gas such as nitrogen, with water vapor at a given pressure and
temperature. The saturated gas then flows through an expansion valve where it is
isothermally reduced to chamber pressure. If the temperature of the gas is held constant
during pressure reduction, the humidity, at chamber pressure, may then be approximated as
the ratio of two absolute pressures.

P

%RH ≈

Humidity produced in the test chamber of this system does not depend on devices such as
psychrometers, dewpoint hygrometers, or solid state sensors for the measurement of water
vapor content. Humidity that is produced is solely dependent on the measurement of absolute
pressures and on the maintenance of isothermal conditions. Precision humidity generation is
determined by the accuracy of these pressure measurements and uniformity of temperature
throughout the generating system.

chamber

P

saturator

. 100

1-1

w

v

X

X

TEST CHAMBER

SATURATOR

AIR SUPPLY

EXHAUST

EXPANSION

VALVE

P s P

c

Figure 1-1

1.2.2 RH Formula For Ideal Gas

The relative humidity formula, equation 1 given in section 1.2.1, is a correct relationship
between pressures and relative humidity when dealing with perfectly isothermal conditions
and perfectly ideal gases. However, under dynamic conditions where some slight
temperature differences do exist and since gases do not behave ideally, any expectation of
this equation to accurately represent the actual relative humidity would be overly optimistic.
In its strictest form, relative humidity is defined in terms of mole fractions and is given as

%RH =

·100

P,T

where Xv = the mole fraction of water vapor in a sample of
moist air at a specific pressure, P, and temperature, T,
and
Xw = the mole fraction of water vapor which would exist in
a sample of air if it were saturated with water vapor at
the same pressure, P, and temperature, T, as the
unsaturated sample Xv.

The mole fraction of water vapor in a sample of gas is given by

P

X =

v

P

where Pv = the partial pressure of the gas which is exerted by the
water vapor constituent alone, and

P = the absolute (or total) pressure of the gas, which is
also equal to the sum of the partial pressures exerted
by the water vapor and dry air constituents.

When a gas is fully saturated with water vapor, the partial pressure, Pv, exerted by the water
vapor constituent is a known quantity, ew(T), and is termed "the saturation vapor pressure of
air with respect to water". Since, at saturation, Pv = ew(T), the mole fraction equation of a
saturated gas may be written as

ew(T)

X =

P

1-2

where ew(T) = the saturation vapor pressure of air with respect to
water (at temperature T), and is the partial pressure
exerted by the water vapor constituent,
and

P = the absolute (or total) pressure of the gas.

The mole fraction of water vapor which would exist in a saturated gas sample at the chamber
pressure, Pc, and chamber temperature, Tc, would be the quantity, Xw, which is needed to
calculate the relative humidity relationship previously discussed. Here, the mole fraction,
under saturated conditions, may be expressed by

ew(Tc)

Xw =

P

c

where ew(Tc) = the saturation vapor pressure of air with respect to
water at the chamber temperature, Tc, and
Pc = the measured absolute pressure in the chamber
expressed in the same units as ew(Tc).

The other quantity, Xv, required for the calculation of relative humidity, is that mole fraction
of water vapor which actually exists in the air sample within the chamber at pressure Pc, and
temperature Tc. If the chamber pressure, Pc, were used in the calculation of the mole fraction

Xv, the expression would be

P

Xv =

v

P

c

which would require direct measurement of the water vapor content. However, this
requirement is eliminated by using the relationship

P

s

ew(Ts)

=

P

v

P

c

where ew(Ts) = the saturation vapor pressure of air with respect to
water at the temperature of saturation, Ts, (the
saturation temperature), and
Ps = the measured absolute (or total) pressure at which the
sample is saturated (the saturation pressure).

The basis for this relationship lies in the fact that the number of molecules of the constituents
within a sample of gas remain constant regardless of the pressure or temperature, provided
that the temperature or pressure applied does not cause a change in phase (i.e., gas to liquid).

Since the saturation vapor pressure, ew(T), is a well known function of the temperature alone,
the total pressure at saturation, Ps, may be adjusted to any reasonable value to achieve the
desired mole fraction of water vapor. Relying on this relationship, the mole fraction of water
vapor entering the chamber (and at chamber temperature) may be written as that mole
fraction of water vapor existing in the saturator at the saturation pressure and temperature.
Thus,

ew(Ts)

Xv =

P

s

1-3

The relative humidity may now be expressed in terms of these other quantities by returning to

w

v

X

X

⋅





























c

cw

s

sw

P

Te

P

Te

)(

)(

( )

Te

⋅⋅

s

c

P

P

),('

),('

ccw

ssw

TPe

TPe

s

c

P

P

the original definition and substituting in the appropriate expressions.

%RH =

·100

P,T

=

100

After rearrangement of terms, the relative humidity formula for ideal gases may then be
expressed as

%RH =

sw

( )

Te

cw

100 eq.(2)

where ew(Ts) = the saturation vapor pressure at the saturation
temperature, Ts,
ew(Tc) = the saturation vapor pressure at the chamber
temperature, Tc,
Pc = the absolute pressure in the chamber, and
Ps = the absolute pressure in the saturator.

1.2.3 RH Formula For Air

Air, a mixture of gases with varying compressibilities, exhibits non-ideal properties, which
affect the saturation vapor pressure, ew(T). The saturation vapor pressures, ew(Ts) and ew(Tc),
in the relative humidity formula of 1.2.2, must be replaced by their "effective" saturation
vapor pressures which are related to the ideal SVP by

ew'(P,T) = ƒw(P,T) ew(T)
where ew'(P,T) = the "effective saturation vapor pressure of air with
respect to water" at absolute pressure, P, and
temperature, T, and
ƒw(P,T) = the "enhancement factor for moist air" at pressure, P,
and temperature, T.

The relative humidity formula for air, based on the effective saturation vapor pressures, is
then written as

%RH =

·

· 100

and, after making the appropriate substitutions, is expressed by

%RH =

ƒw(Ps,Ts)
ƒw(Pc,Tc)

·

ew(Ts)

ew(Tc)

·

P

c

100

·

P

s

eq.(3)

1-4

It can now be seen by inspection of the relative humidity formula, expressed in its final form

( ) ( )



















+⋅+















+

−

=

∑

15.273ln15.273

2

6

0

TDTC

i

i

i

in equation 3, that known relative humidities may be accurately generated, using air, through
measurement and control of pressure and temperature alone.

1.2.4 Pressure Ratio

P

The term

c

, in equation 2 of section 1.2.2 and equation 3 of section 1.2.3, is simply the

P

s

ratio of the chamber pressure to the saturator pressure. This is the "idealistic" portion of the
relative humidity formula which ignores minor temperature differences between the saturator
and chamber. It also assumes that moist air behaves as an ideal gas. This ratio closely
approximates the actual relative humidity, and is often used alone to express the humidity
when ease of calculation outweighs the need for the additional accuracy provided by the
temperature and pressure corrections. The pressures Pc and Ps are measured directly through
the use of high accuracy absolute pressure transducers.

1.2.5 Effective Degree Of Saturation

ew(Ts)

The term

ew(Tc)

, in equation 2 of section 1.2.2 and equation 3 of section 1.2.3, referred to as

the "effective" degree of saturation, is a temperature correction ratio which accounts for
super-saturation and under-saturation of the gas in the saturator, at temperature Ts, with

respect to the chamber temperature, Tc, due to any small temperature differences which may
exist between them. When the chamber and saturation temperatures are identically matched,

the effective degree of saturation is exactly equal to 1.0 and no temperature correction takes
place. To obtain the effective degree of saturation when temperature differences do occur,
the saturation vapor pressures at the saturation and chamber temperatures, Ts and Tc, must be

calculated. There have been several formulas derived which express the saturation vapor
pressure as a function of temperature. However, the most accurate formulation currently
available for the limited range of 0 to 100 °C is that of Wexler, given as

ew(T) = exp

where C0 = -2.9912729 x 103
C1 = -6.0170128 x 103
C2 = 1.887643854 x 101
C3 = -2.8354721 x 10-2
C4 = 1.7838301 x 10-5
C5 = -8.4150417 x 10
C6 = 4.4412543 x 10

-10

-13

D = 2.858487
T = temperature of the gas in °C.

Saturation vapor pressures, ew(T), calculated with this formula are expressed in Pascals.
When taking the ratio of ew(Ts) to ew(Tc), the units will cancel, leaving the effective degree of
saturation as a dimensionless quantity.

1-5

1.2.6 Enhancement Factor Ratio

( )

( )
























−+











− 11

Te

P

P

Te

w

w

βα

ƒw(Ps,Ts)

The term

ƒw(Pc,Tc)

, in equation 3 of section 1.2.3, referred to as the "enhancement factor

ratio", corrects for the non-ideal behavior of air when it is used as the carrier gas. Note that
the individual enhancement factors, ƒw, are functions of two independent variables; pressure,

P, and temperature, T. Since temperature differences within the system are relatively quite
small, and pressure differences relatively large, it is typically the pressure terms, Pc and Ps,

which dominate the formulas and bring about the greatest change in the enhancement factor
ratio. As applied to the two pressure humidity generator, this enhancement factor ratio may
be loosely viewed then as a pressure correction. At a relative humidity of 100%, the
pressures Pc and Ps would be equal, causing the enhancement factor ratio to equal 1.0

(ignoring temperature differences), thereby not affecting the relative humidity calculation.
Conversely, at low relative humidities (i.e., 5%), where the pressures Pc and Ps differ greatly

(i.e., Ps≈20 • Pc), the enhancement factor ratio may exceed 1.06, affecting relative humidity
calculations by 0.3% or more. A formula for calculation of the enhancement factor ƒw(P,T)
at any given pressure and temperature is given by Greenspan as

ƒw(P,T) = exp

where P = the absolute pressure in Pascals, and
ew(T) = the saturation vapor pressure (in Pascals) at

temperature, T.

The two remaining variables, α and β, as derived by Greenspan are given as

3

α =

and β = exp

∑

i=0

AiTi

3

∑

i=0

BiTi

where A0 = 3.53624 x 10
A1 = 2.93228 x 10
A2 = 2.61474 x 10

-4

-5

-7

A3 = 8.57538 x 10-9
B0 = -1.07588 x 101
B1 = 6.32529 x 10
B2 = -2.53591 x 10

-2

-4

B3 = 6.33784 x 10-7, and
T = temperature of the gas in °C.

This formula for the enhancement factor is valid for pressures up to approximately 300 PSIA
and over the temperature range of 0 to 100 °C. Therefore it is also valid over the operating
range of the humidity generator. Note that to obtain the enhancement factor ratio, the
formula must be calculated once at the saturation pressure and temperature, Ps and Ts, and
then again at the chamber pressure and temperature, Pc and Tc.

1-6

1.3 SPECIFICATIONS

Relative Humidity Range: ---------------------------------------------------- 10 to 95 %RH
Relative Humidity Uncertainty: @ Pc Tc * ------------------------------------- 0.5 %RH
Chamber Temperature Range: ----------------------------------------------- 0 °C to 70 °C
Chamber Temperature Range: (Optional) -------------------------------- -10 °C to 70 °C
Chamber Temperature Uniformity: ** ----------------------------------------------- 0.1 °C
Chamber Temperature Uncertainty: * ---------------------------------------------- 0.06 °C
Chamber Pressure Range: ---------------------------------------------------------- Ambient
Chamber Pressure Uncertainty: * ------------------------------------------------- 0.15% FS
Display Resolution: ------------------------------------------------------------------------ 0.01
Gas Flow Rate Range: *** --------------------------------------------------- 5 to 20 L/min
Gas Flow Rate Resolution: ----------------------------------------------------- 0.02 L/min
Gas Flow Rate Uncertainty: * -------------------------------------------------------- 2% FS
Gas Type: --------------------------------------------------------------------- Air or Nitrogen
Gas Pressure Rating: (MAWP) ----------------------------------------------------175 PSIG
Heating: ------------------------------------------------- Stainless Steel Immersion Heater
Heating/Cooling Rate: -------------------------------------- 2.5 Minutes Per °C Average
Cooling: --------------------------------------------- 1/3 hp R-134A Refrigeration System
Chamber Window: ------------------------------------------ 6" x 6" (152 mm x 152 mm)
Access Port: ----------------------------------------------- 1.9" (48 mm) port in right side

Physical Dimensions:
2500 --------------------- 20.25" (514 mm) H x 33" (838 mm) W x 20" (508 mm) D
2500ST ------------------- 23.25" (591 mm) H x 36" (914 mm) W x 23" (584 mm) D

Physical Dimensions with cart:
2500 ---------------------------- 53.5" (1.36 m) H x 40" (1.02 m) W x 23" (584 mm) D
2500ST ------------------------- 56.5" (1.44 m) H x 43" (1.09 m) W x 26" (660 mm) D

Chamber Dimensions:
2500 -------------------------- 12" (305 mm) H x 12" (305 mm) W x 10" (254 mm) D
2500ST ----------------------- 15" (381 mm) H x 15" (381 mm) W x 12" (305 mm) D

* Represents an expanded uncertainty using a coverage factor, k=2, at an approximate

level of confidence of 95%. Uncertainty for relative humidity is not specified
below 0 °C.

** When operating at a test temperature that is within ±10 °C of the ambient room

temperature.

*** Optional 10 to 40 L/min flow rate available.

1.3.1 Facility Requirements

Standard Electrical Power: -------- 100VAC @ 50Hz or 120VAC @ 60Hz, 15 amps
HV Electrical Power (Optional): --- 220VAC @ 50Hz or 240VAC @ 60Hz, 8 amps
Air Supply: ------ Clean, oil free instrument air @ 175 PSIG and 0.7 cfm (20 L/min)

1.3.2 Environmental

Operating Temperature: ----------------------------------------------------- 15 °C to 30 °C
Storage Temperature: --------------------------------------------------------- 0 °C to 50 °C
Relative Humidity: ------------------------------------------ 5% to 95 % non-condensing

1-7

STD BUS

STD-PS

STD-LCD

STD-CPU

STD-A/D

STD-MEM

LCD-INV

LCD

SSRB

TIB

ATB

KB

CONSOLE

PORT

PRINTER

PORT

POWER SUPPLY BOARD DISPLAY DRIVER BOARD

ANALOG BOARD

MEMORY BOARD

ANALOG TERMINAL

BOARD

KEYBOARD

SOLID STATE

RELAY BOARD

TERMINAL INTERFACE

BOARD

INVERTER BOARD

LIQUID CRYSTAL

DISPLAY

ATB

KB

CONSOLE

PORT

PRINTER

PORT

ANALOG TERMINAL

BOARD

KEYBOARD

1.4 COMPUTER CONTROL SYSTEM

1.4.1 General Description

Reference Drawings 91D25903 & 91D25913

The Computer Control System (figure 1-2), consisting of several STD bus plug-in circuit
board modules, is embedded in the humidity generator. The computer controls all aspects of
the humidity generation process (i.e., controlling temperatures, pressures, etc.) as well as
performing all human interface functions of keypad input and information display. The
computer also controls printer operation and interfaces with an external computer (optional)
for bi-directional RS-232C communications.

The Computer Control System is considered a "single point automation" unit, controlling the
functions of the humidity generator to bring it to any one operator input setpoint. The
computer will always control the system at the most current setpoint that has been input,
either via keypad input, or from external computer input thru the RS-232C port. The
Computer Control System knows nothing of past or future setpoints, requiring the use of an
external computer if automated temperature / humidity profiling is desired.

The Computer Control System consists of the following key components:

1) STD bus computer system, consisting of:

a) CPU card with 64180 processor (STD-CPU)
b) 8 channel, 15 bit A/D converter board (STD-A/D)
c) Memory board (STD-MEM)
d) Liquid crystal display driver board (STD-LCD)
e) Power supply converter board (STD-PS)

2) 256 x 128, backlit, dot matrix Liquid Crystal Display (LCD) module.

3) 16 key front panel keypad.

Figure 1-2

1-8

1.4.2 Central Processing Unit (STD-CPU)

The Central Processing Unit consists of a 64180 micro-processor, along with all supporting
hardware required to interface with the other devices. During the humidity generation
process, the main processing unit executes programming designed to control the parameters
needed to generate relative humidity, such as pulsing heaters and operating valves. Virtually
all functions of the system are controlled by this Central Processing Unit which is responsible
for system timing, user interfacing, information display, and parameter control.

1.4.3 Liquid Crystal Display (LCD)

The display incorporated into the 2500 humidity generator is a backlit, 256 x 128, dot matrix
Liquid Crystal Display (LCD). It is used for the purpose of displaying system information
such as setpoints, measurements, and any other information pertinent to the operation of the
2500 humidity generator.

1.4.4 Liquid Crystal Display Driver (STD-LCD)

The Liquid Crystal Display Driver (STD-LCD) receives display commands and data from the
Central Processing Unit then converts these into the signals required to drive the Liquid
Crystal Display module. It also incorporates a voltage inversion circuit, which converts +5
VDC input to a -21 VDC output required by the LCD module.

Contrast adjustment is controlled via a 0 to -5 VDC analog output from the STD-CPU. The
variable voltage is fed by a single wire from the STD-CPU to the STD-LCD driver board.
This voltage level, and the resulting contrast, is adjusted by the user from the front panel
keypad. (See section 3.2.2.1)

1.4.5 Keypad

The 4 x 4 Keypad provides operator input to the 2500 humidity generator. The keypad is
used to select modes of operation from the menus, enter humidity and temperature points for
humidity generation, and perform any other interface functions where user input is required.
During operation, most of the screens will show four rectangular shaped blocks at the right
side of the display. These blocks correspond with four blank keys on the left side of the
keypad, which will be used to perform various functions within the program.

1.4.6 Memory Card (STD-MEM)

The Memory Card contains both EPROM and battery backed memory. This memory
contains all program and data required for operation of the generator.

1.4.7 Analog to Digital Converter (STD-A/D)

The Analog to Digital Converter board is a 15 bit analog to digital converter, with integral
signal conditioning, used to monitor thermistor resistance, pressure transducer voltage, and
flowmeter voltage. It has a useable voltage range of 0 to +5 VDC.

1-9

1.5 ELECTRICAL SYSTEM

1.5.1 AC Power Distribution

Reference Drawings 91S25906 thru 91S25912

The 2500 requires a 120 VAC/60Hz or 100 VAC/50Hz, single phase, 15 amp primary power
source (240 VAC/60Hz or 220 VAC/50Hz, single phase, 10 amp primary power source for
HV power option). From CBS1, primary power is applied to TB1 terminals 1 & 2. From
TB1 the primary power is distributed to the 24 VAC step-down transformer (TR1), the
refrigeration compressor (C1) through SSR8, the presaturator heaters (H1 & H2) through
SSR9, the fluid heater (H3) through SSR10, the fluid pump (FP1) through SSR6, and the
console fan (CF1) through SSR7.

1.5.2 Power Supply 24 VAC

Reference Drawing 91S25906

The 24 VAC Step-down Transformer (TR1) provides 24 VAC power for all solenoid valves,
as well as power input for the STD Power Supply Card (STD-PS) located in the computer
card cage.

1.5.3 Power Supply (STD-PS)

Reference Drawing 91S25906

The Power Supply Card (STD-PS) is a multiple isolated output voltage source providing
power to the STD bus computer system, as well as the flow transducer, pressure transducers,
solid state relay board (SSRB), terminal interface board (TIB), stepper motor drives (SMD-1
& SMD-2), the liquid lever monitor boards (LL1 & LL2), and the LCD backlight inverter
circuit.

The Power Supply Card receives power from the 24 VAC step-down transformer (TR1), then
rectifies and filters this into +24 VDC unregulated. The unregulated +24 VDC feeds an
onboard DC to DC converter which provides the regulated +5 VDC and ±12 VDC for the
STD bus and other equipment. The unregulated +24 VDC also powers the stepper motor
drivers (SMD-1 & SMD-2). Note that the +24 VDC Return is electrically isolated from the
+5 VDC and ±12 VDC Common.

Each item listed below utilizes the power from the Power Supply Card (STD-PS) for its
particular voltage requirements.

Voltage Transducer
+24 VDC Stepper motor drivers (SMD-1 & SMD-2)
+12 VDC Mass flow transducer (T1)
+12 VDC 50 PSIA transducer (T2)
+12 VDC 150 PSIA transducer (T3)
±12 VDC A/D board (STD-A/D)

-12 VDC LCD backlight
+5 VDC All STD bus cards (STD-CPU,STD-LCD,STD-MEM,STD-A/D)
+5 VDC Solid state relay board (SSRB)
+5 VDC Terminal interface board (TIB)
+5 VDC Liquid level boards (LL1 & LL2)

1-10

1.5.4 Analog Inputs (STD-A/D)

The temperature, flow, and pressure transducers are measured by the Analog to Digital
Converter (STD-A/D). Each of these is discussed further in the following sections.

1.5.4.1 Temperature Measurement

Reference Drawing 91S25912

Four 10KΩ thermistors are used for temperature readout and control with continuous real

time display by the computer. All are easily removable for calibration.

ATB Channel #

1. Saturation Temperature (RTD0) (indication and control) 0

2. Presaturation Temperature (RTD1) (indication and control) 1

3. Expansion Valve Temperature (RTD2) (indication and control) 2

4. Test Chamber Temperature (RTD3) (indication only) 3

The thermistor temperatures are measured by the STD bus Analog to Digital Converter Board
(STD-A/D) with a ratio of approximately 0.01 °C/bit. Since the temperatures measured by
the STD-A/D board are based on ideal R-T curves, further calibration to actual temperature
values is performed by the STD-CPU prior to use or display (refer to 4.2.2 for calibration).

A reference resistor of approximately 10KΩ is connected to channel 4 of the ATB, and is

used to compensate for short and long-term drift of the temperature measurement electronics
of the STD-A/D circuitry. Deviations from the reference resistor's nominal value are used to
mathematically offset the measured values of the four thermistor probes.

1.5.4.2 Mass Flow Transducer (T1)

Reference Drawing 91S25912

The mass flow control system utilizes a thermal type Mass Flow Transducer. Mass flow rates
through the generator are manually setable from 2 to 20 L/min by keypad entry. The mass
flow rate is displayed on the Liquid Crystal Display (refer to 4.2.5 for calibration).

The flow transducer is powered by +12 VDC from the STD power supply (STD-PS).
Transducer output is 0 to 2.5 VDC for a mass flow rate of 0 to 20 L/min. The output voltage
is connected to channel 7 of the ATB for measurement by the STD-A/D circuit board.

1.5.4.3 50 PSIA Pressure Transducer (T2)

Reference Drawing 91S25912

The 0-50 PSIA Pressure Transducer is of the piezoresistive type. When saturation pressures
are above 50 PSIA this transducer continually monitors chamber pressure. When the
saturation pressure is below 50 PSIA it monitors saturation pressure, but switches to chamber
pressure (barometric) once every five minutes by pressure select solenoid SOL5. The output
voltage is connected to channel 5 of the ATB for measurement by the STD-A/D circuit board.
Transducer output is 0 to 5 VDC for 0 to 50 PSIA (refer to 4.2.3 for calibration).

1-11

1.5.4.4 150 PSIA Pressure Transducer (T3)

Reference Drawing 91S25912

The 0-150 PSIA Pressure Transducer is of the piezoresistive type. This transducer is used to
measure saturation pressures above 50 PSIA. The output voltage is connected to channel 6 of
the ATB for measurement by the STD-A/D circuit board. The output of the transducer is 0 to
5 VDC for 0 to 150 PSIA (refer to 4.2.3 for calibration).

1.5.5 Control Logic

All control is performed digitally at a logic level of 5 VDC. Activation of all devices is
accomplished by applying a logic low to the control input of the associated solid state relay or
other coupling device.

1.5.5.1 Air Supply Solenoid Valve (SOL1)

Reference Drawing 91S25907

The Air Supply Solenoid Valve is activated (air on) by applying a low from the STD-CPU
(monitored at TIB terminal C5) to the optical input (-) side of SSR5 on the Solid State Relay
Board (SSRB). Valve actuation voltage is 24 VAC.

1.5.5.2 Refrigerant Solenoid Valve (SOL2)

Reference Drawing 91S25907

The Refrigerant Solenoid Valve, when activated, allows refrigerant to be injected into the
refrigeration evaporator to remove heat from the heat transfer fluid. This valve is activated
by applying a low from the STD-CPU (monitored at TIB terminal C0) to the optical input (-)
side of SSR0 on the Solid State Relay Board (SSRB). Evaporator temperature is controlled
through fixed frequency pulse width modulation of the refrigerant solenoid valve. Valve
actuation voltage is 24 VAC.

1.5.5.3 Pressure Bleed Solenoid Valve (SOL3)

Reference Drawing 91S25907

The Pressure Bleed Solenoid Valve, when deactivated (normally open), vents system pressure
during all SHUTDOWN procedures and when electrical power is OFF. This valve is
activated by applying a low from the STD-CPU (monitored at TIB terminal C3) to the optical
input (-) side of SSR3 on the Solid State Relay Board (SSRB). Valve actuation voltage is 24
VAC.

1-12

1.5.5.4 Pressure Select Solenoid Valve (SOL5)

Reference Drawing 91S25907

The Pressure Select Solenoid Valve, when activated, allows the 0-50 PSIA transducer to
measure the saturation pressure. This valve is activated by applying a low from the STD­CPU (monitored at TIB terminal C4) to the optical input (-) side of SSR4 on the Solid State
Relay Board (SSRB). Valve actuation voltage is 24 VAC.

1.5.5.5 Heat Transfer Fluid Heater (H3)

Reference Drawing 91S25908

The Heat Transfer Fluid Heater is a 500 watt resistive heating element activated by a two
stage control process. The heat limit switch (HLS2) must be in the normally closed position,
indicating that the fluid temperature is within allowable limits (below 85 °C). Activation is
then accomplished by applying a low from TIB channel B5 to the optical input (-) side of
SSR10. Heater temperature is controlled through fixed frequency pulse width modulation.
Heater voltage is 100/120 VAC (220/240 VAC for HV option).

1.5.5.6 Presaturator Heaters (H1, H2)

Reference Drawing 91S25908

The Presaturator Heaters are resistive heating elements, activated by a two stage control
process. The heat limit switch (HLS1) must be in the normally closed position, indicating
that the presaturation temperature is within allowable limits (below 95 °C). Activation is
then accomplished by applying a low from TIB channel B6 to the optical input (-) side of
SSR9. Presaturator heater temperature is controlled through fixed frequency pulse width
modulation. Heater voltage is 100/120 VAC and wiring configuration is dependent on the
primary power supply. In standard units the heaters are wired in parallel where HV option
units have the heaters wired in series.

1.5.5.7 Expansion Valve Heaters (H4, H5)

Reference Drawing 91S25907

The Expansion Valve Heaters, when activated, are used to warm the expansion valve body,
offsetting the cooling effects due to gas expansion. The heaters are activated by applying a
low from the STD-CPU (monitored at TIB terminal C1) to the optical input (-) side of SSR1
on the Solid State Relay Board (SSRB). Heater temperature is controlled through fixed
frequency pulse width modulation. Heater voltage is 24 VAC.

1.5.5.8 Fluid Circulation Pump (FP1)

Reference Drawing 91S25907

The Fluid Circulation Pump is a magnetically coupled pump energized by applying a low
from the STD-CPU (monitored at TIB terminal C6) to the optical input (-) side of relay SSR6
on the Solid State Relay Board (SSRB). Pump voltage is 100/120 VAC (220/240 VAC for
HV option).

1-13

1.5.5.9 Refrigeration Compressor (C1)

Reference Drawing 91S25908

The Refrigeration Compressor is energized by applying a low from TIB channel B4 to the
optical input (-) side of SSR8. Compressor voltage is 100/120 VAC (220/240 VAC for HV
option).

1.5.5.10 Flow Valve (V1) – Actuation

Reference Drawing 91S25910

The Flow Valve is used to control system mass flow rate and is driven indirectly via pulses
from the Terminal Interface Board (TIB) channels B1 & B3, which trigger stepper motor
driver SMD-1. Pulses on channel B1 close the valve, while pulses on channel B3 open the
valve. The stepper motor driver is powered from the unregulated 24 VDC output of the
STD-PS circuit board in the STD card cage. The HOME or FULLY CLOSED position is
sensed by a low at TIB channel A1 resulting from the contact closure of limit switch SL-1.

1.5.5.11 Expansion Valve (V2) – Actuation

Reference Drawing 91S25911

The Expansion Valve is used to control saturation pressure and is driven indirectly via pulses
from the Terminal Interface Board (TIB) channels B0 & B2, which trigger stepper motor
driver SMD-2. Pulses on channel B0 will close the Expansion Valve, while pulses on
channel B2 will open the Expansion Valve.

The stepper motor driver is powered from the unregulated 24 VDC output of the STD-PS
circuit board. The HOME or FULLY CLOSED position is sensed by a low at TIB channel
A0 resulting from the contact closure of limit switch SL-2.

1.5.5.12 Reservoir Liquid Level Transducer (LL1)

Reference Drawing 91S25910

The Reservoir Liquid Level Transducer monitors reservoir water level, which is displayed on
the computer screen. A voltage corresponding to the reservoir water level is output from LL1
to the STD-CPU via TB2-9. When an empty indication occurs during RH generation an
audible alarm will sound accompanied by a warning message. An empty reservoir during
start up forces a shutdown, accompanied by both audible and visual alarms. The liquid level
board is powered from +5 VDC.

1-14

1.5.5.13 Presaturator Liquid Level Transducer (LL2)

Reference Drawings 91S25907 and 91S25910

The Presaturator Liquid Level Transducer is used in maintaining the presaturator distilled
water level constant. When the water level drops below the control point, the sensor pulls
channel A2 of TIB low, informing the CPU of the condition. The CPU will then activate
solenoid SOL4, allowing distilled water into the presaturator until LL2 puts a high on channel
A2 signifying a full or filled condition.

SOL4 is activated by applying a low from the STD-CPU (monitored at TIB terminal C2) to
the optical input (-) side of SSR2 on the Solid State Relay Board (SSRB). If the presaturator
does not fill to the control point (i.e., reservoir empty) within approximately 5 minutes, the
system will shut down. The liquid level board is powered from +5 VDC.

1.5.5.14 Console Fan (CF1)

Reference Drawing 91S25907

The Console Fan is energized by applying a low from the STD-CPU (monitored at TIB
terminal C7) to the optical input (-) side of solid state relay SSR7 on the Solid State Relay
Board (SSRB). The fan is activated when the CPU senses a cabinet temperature above 30 °C
or when control is enabled (reference section 3.2.5). Fan voltage is 100/120 VAC (220/240
VAC for HV option).

1-15

1.6 PNEUMATIC SYSTEM

TEST CHAMBER

EXHAUST

PRESSURE BLEED

AIR/GAS SUPPLY

(RTD1)

(SOL4)

(SAT)

(RV 1)

(V1 )

(T 1)

(G1)

(RE G)

(SOL3)

(SOL1)

(V2 )

(T 2)

(T 3)

(RES)

(PSAT)

(CV 1)

(NORMALLY- OPEN)

(SOL5)

DISTILLED

WATER

IN

(RTD2)

(RTD3)

1.6.1 General Description

Reference Drawing 91S25916

The 2500's pneumatic system (figure 1-3) requires an air supply that is clean and oil free, and
should be capable of supplying a maximum pressure of 175 PSIG at a flow rate of 20 L/min.
An air supply filtered to a particle size of 0.5 microns or less, a hydrocarbon content of 1
PPM or less, with a pressure dewpoint no greater than 10 °C is recommended. The air supply
is connected to a 1/4" FPT fitting located at the lower rear of the console. From this point,
the airstream is admitted through the air on/off solenoid valve (SOL1) to the console air
supply regulator (REG). After regulation, the airstream passes through the mass flow meter
(T1) to the computer controlled mass flow valve (V1). Mass flow rates are user settable and
displayed on the Liquid Crystal Display.

From the flow control valve, the air flows to the presaturator (PSAT) (refer to 1.6.2). The
presaturator water temperature is maintained at a temperature approximately 15 to 20 °C
warmer than the saturation temperature so as to humidify the airstream to a water vapor
content greater than saturation. The presaturated air then exits the presaturator and enters the
saturator (SAT) (refer to 1.6.3). As the air flows through the saturator, excess water vapor is
condensed as the airstream is cooled to saturation temperature, achieving 100% saturation.
Saturation pressure is measured as the air exits the saturator and flows to the expansion valve
(V2) (refer to 1.6.4).

The computer controlled expansion valve allows the saturated high pressure airstream to be
reduced to chamber pressure by varying the orifice from nearly closed to fully open
depending upon the required saturation pressure. After expansion, the air flows into the test
chamber at the desired relative humidity conditions. The airstream exits the test chamber
through the chamber exhaust port, located at the bottom rear of the test chamber (if the access
port is sealed).

Figure 1-3

1-16

1.6.2 Presaturator

The airstream of a two-pressure generator must be 100% saturated with water vapor at test
temperature on the high-pressure (saturator) side of the expansion valve. This is
accomplished by first passing the airstream through a "presaturator" (PSAT). The
presaturator is a vertical pressure vessel presenting a water surface to the incoming airstream
and is maintained constant at a temperature 15 to 20 °C warmer than the desired system
(chamber) temperature. After presaturation, the air exits the top of the presaturator and is
directed to the saturator.

Presaturation temperature, sensed by a 10KΩ thermistor, is adjustable and controllable from
20 to 90 °C. Heating of the presaturator is provided by two 250-watt stainless steel
immersion type heaters, powered through a solid state relay (SSR9).

The presaturator water level is maintained automatically via computer control of the
presaturator liquid level control solenoid valve (SOL4). This valve controls the flow of
distilled water from the supply reservoir (RES) (refer to 1.6.5) to the presaturator,
maintaining the level constant to within approximately 1/16 inch (1 oz.).

1.6.3 Saturator

Saturation of the airstream to 100% relative humidity, upstream of the expansion valve, is
accomplished in a "tube in shell" type heat exchanger referred to as the "saturator". The
humidified airstream from the presaturator, humidified to an absolute moisture content
greater than saturation at final saturation temperature, flows through the saturator. Excess
water vapor is condensed from the airstream as it establishes equilibrium with the heat
transfer fluid, ensuring that the airstream has a value of 100% relative humidity at fluid
(saturation) temperature. The saturation pressure is monitored as the airstream exits the
saturator. This measurement is used in the calculation and control of the desired relative
humidity.

1.6.4 Expansion Valve

After exiting the saturator, the 100% saturated high-pressure airstream is reduced to chamber
pressure through the "expansion valve". The expansion valve (V2) is an electro-mechanically
actuated valve, controlled from the computer, using feedback from the saturator and chamber
pressure measurements. This valve is heated and thermally insulated to maintain the valve
body above the dewpoint of the adiabatically cooled airstream.

1.6.5 Reservoir

The reservoir is a pressure vessel, constructed of 300 series stainless steel, and holds a one
gallon supply of distilled water for the presaturator. This vessel is maintained at system
pressure and, upon demand, allows reserve distilled water to flow freely to the presaturator.
If a low level reservoir water condition is sensed during operation of the humidity generator,
a warning message will begin flashing on the display, accompanied by an audible warning
beep.

A one gallon supply of distilled water may last from 12 hours to 9 months of continuous
operation, depending on the temperature and RH being generated. High temperatures and
high humidities require large amounts of water, while low temperatures and low humidities
require very small amounts of water. See section 3.2.9 for reservoir filling procedure.

1-17

While not exact, the following simple formulas may be used to approximate continuous run
time at specific RH and temperature values.

Hours per gallon @ 0 °C, 20 L/min ≈

Hours per gallon @ 25 °C, 20 L/min ≈

Hours per gallon @ 50 °C, 20 L/min ≈

Hours per gallon @ 70 °C, 20 L/min ≈

Using lower flow rates will increase the "hours per gallon" time directly. For instance, a 2:1
decrease in flow (i.e., 10 L/min) causes a corresponding 2:1 increase in time.

68000

%RH

14000

%RH

3500

%RH

1200

%RH

1-18

1.7 HEAT TRANSFER FLUID SYSTEM

FLUID FILL PORT.

(SAT)

REFRIGERANT

OUT
IN

(H3)

(EX1)

TEST

CHAMBER

(FP1)

(RTDØ)

1.7.1 General Description

Reference Drawing 91S25917

The Model 2500 Benchtop Humidity Generator incorporates a unique test chamber, in that it
has a fluid shell surrounding the test space (figure 1-4). Temperature controlled fluid,
consisting of approximately 30-40% water and 60-70% propylene glycol, is circulated at a
rate of nearly 10 gallons per minute through the fluid shell by a magnetically coupled
centrifugal pump (FP1). The fluid mass and fast circulation rate result in inherent
temperature stability allowing a very stable and precise humidity to be generated. The
chamber interior and fluid shell are constructed of 300 series stainless steel assuring rustproof
quality. All seams are heliarc welded for hermetic sealing of the liner and shell.

In this closed loop, non-pressurized system, conditioned fluid flows from the pump outlet to
the saturation temperature/control sensor (RTD0). From this point, the fluid circuit splits;
one path flowing through the test chamber fluid shell and the other path flowing through the
saturator assembly:

Path 1) Temperature conditioned heat transfer fluid flows through the test chamber fluid

shell, exits at the upper left of the fluid shell and enters the refrigeration evaporator
(EX1). The refrigeration evaporator is a single pass, tube in shell type, heat
exchanger allowing fluid cooling. After cooling, fluid enters the immersion heater
housing, flows over the immersion heater (H3), and exits to the circulation pump
intake, completing the chamber fluid circuit.

Path 2) Temperature conditioned heat transfer fluid enters the saturator assembly (SAT) at

the opposite end from the airstream and flows through the saturator to the expansion
tank (located on top of the test chamber). The saturator fluid circuit then merges
with the chamber fluid circuit at the exit of the chamber fluid shell.

Figure 1-4

1-19

(CON)

(FD)

(SOL2)

(V3)

(V4)

(C1)

(EX1)

CHAMBER

IN

OUT

(V5)

1.7.2 Fluid Heating

Reference Drawing 91S25917

The 2500's heat transfer fluid is heated by a 500 watt immersion heater (H3) (figure 1-4).
The immersion heater is installed into a copper heater housing and is located in the main fluid
path between the refrigeration evaporator (EX1) and circulation pump (FP1). Primary power
to the immersion heater is switched by a solid state relay (SSR10). Pulsed power to the
immersion heater is controlled by the computer, using feedback from the fluid control
(saturation temperature) sensor (RTD0). High temperature disconnect of the immersion
heater is provided for by a bi-metal temperature sensing element, (HLS2) operating single
pole contacts that disconnect the primary power.

1.7.3 Fluid Refrigeration

Reference Drawing 91S25918

The heat transfer fluid of the 2500 is cooled by an R-134A refrigeration system (figure 1-5).
The refrigerant is compressed from a low-pressure vapor into a heat laden high-pressure
vapor by the refrigeration compressor (C1). High-pressure vapor flows to the air-cooled
condenser (CON) where it is cooled to a high-pressure liquid as heat is removed. Condensed
refrigerant then flows through the filter-drier (F2) and passes to the refrigerant solenoid valve
(SOL2). Primary power to the refrigerant solenoid valve is switched by a solid state relay
(SSR0). Pulsed power to the refrigerant valve is controlled by the computer, using feedback
from the fluid control (saturation temperature) sensor (RTD0).

Upon demand from the computer, refrigerant is pulsed to the thermostatic expansion valve
(V3), and metered into the refrigerant evaporator (EX1). The refrigerant expands, changes to
a low-pressure vapor as it absorbs heat, and the heat laden vapor is then piped to the suction
side of the compressor and the cycle is repeated. Liquid refrigerant also flows to a small
thermostatic expansion valve (V4), which, depending upon suction line temperature, meters
small amounts of refrigerant into the suction side of the refrigeration compressor during
stand-by or hot-gas bypass (V5) modes. This allows the compressor to operate under a no­load condition until a cooling demand is sent to the refrigerant solenoid, allowing for
continuous operation, eliminating repeated on/off cycling. During times of high heat
demand, such as a temperature setpoint change (i.e., 25 °C to 50 °C), the refrigeration
compressor will automatically shut down until such time as cooling is again demanded. Once
started, the compressor will then remain on as cooling is continuously required to hold the
heat transfer fluid at setpoint temperature.

Figure 1-5

1-20

Section 2

INSTALLATION

2.1 GENERAL

Preparations should be made to have adequate bench or floor space and a source of primary
power available at the location of use. A clean oil free instrument quality air supply must
also be available if the generator is installed without the cart air supply.

2.2 FACILITIES REQUIRED

Reference Drawing 91D25901

2.2.1 Bench / Floor Space

A bench and/or floor, capable of supporting approximately 300 pounds, with a minimum
space of 24" (610mm) deep x 40" (1.02m) wide is recommended and 27" (686mm) deep x
43" (1.09m) wide for 2500ST)(drawing 91D25901). Allow an additional 20" (508mm) in
width for clearance, if possible, so as to allow complete opening of the chamber door and
access to the test port.

LEFT

RIGHT

RESERVOIR FILL PORT

COMPUTER / PRINTER
INTERFACE

ACCESS PORT

CHAMBER EXHAUST PORT

THUNDER SCIENTIFIC CORPORATION

2500 HUMIDITY GE NERATOR

FRONT

AIR SUPPLY INPUT (1/4" FPT)

BACK

MAIN POWER SWITCH (CBS1)

AC POWER

Figure 2-1

2.2.2 Power

The 2500 humidity generator requires a primary power source of 120 VAC/60Hz or 100
VAC/50 Hz at 15 amps minimum (240 VAC/60 Hz or 220 VAC/50 Hz at 10 amps minimum
for HV option). The pneumatic cart with it's 1/2 horsepower air compressor requires an
additional power source of 120 VAC/60 Hz or 100 VAC/50 Hz at 8 amps minimum (240
VAC/60Hz or 220 VAC/50 Hz at 5 amps minimum for HV option).

2-1

2.2.3 Air Supply (if used without pneumatic cart)

The 2500's pneumatic system requires an air supply that is clean and oil free. If the generator
is to be used without the pneumatic cart, instrument air at a maximum pressure of 175 PSIG
and capable of a flow rate of at least 20 L/min is recommended. The air supply should be
filtered to a partical size of 0.5 microns or less, a hydrocarbon content of 1 PPM or less, with
a pressure dewpoint of 15 °C or less.

2.2.4 Distilled Water Supply

The 2500 humidity generator requires one gallon (3.8 liters) of double distilled water per fill.
A one gallon supply can last from 12 hours to as many as 6800 hours of continuous use
depending upon the temperature and humidity at which the generator is operated (reference
section 1.6.5). During operation near ambient temperature and 50% RH, one gallon should
last for approximately 290 hours.

2.3 PREPARATION

2.3.1 Chamber Fluid Filling

Reference Fig 2-2 and Drawings 97D25924 & 91S25917

Temperature conditioning of the 2500 test chamber utilizes a 60-70% mixture of propylene
glycol and 30-40% water as the heat transfer fluid. This fluid is circulated by a magnetically
coupled centrifugal pump through the refrigeration and heating system and the fluid shell
surrounding the test chamber.

2.3.1.1 Chamber Fluid Filling Procedure

Chamber fluid filling requires:

T10 Torx Driver (supplied)
Chamber fill funnel (insert into the 5/8" (15.9mm) diameter opening) (supplied)
3 US gallons (11.35 liters) of -100 °C propylene glycol mix (4 US gallons (15.14 liters) for
2500ST) (supplied)

To fill chamber fluid jacket proceed as follows:

1) Remove top right console panel (panel above chamber).

2) Locate fluid fill port (under insulation and labeled "Fluid Fill Port").

3) Remove "Red" cap and insert the chamber fill funnel into fluid fill port.

4) Using 3 U.S. gallons of -100 °C propylene glycol mix (4 U.S. gallons for
2500ST), fill until level is approximately 1/4" (6.35 mm) below the bottom

of the fill port. Note: the fluid should touch the base of the funnel.

5) Remove funnel and replace fluid fill port cap and insulation.

6) Replace top right console panel.

7) Chamber fluid filling is now complete.

See figure 2-2

2-2

THUNDER SCIENTIFIC CORPORATION

2500 HUMID

ITY GENERATOR

FRONT

REMOVE THIS

PANEL

.250" (6.35 mm)

PROPYLENE GLYCOL

3 bottles for the R,
4 bottles for the ST

CHAMBER
FILL FUNNEL

PULL OFF
RED CAP

FILL PORT

FILL HERE

PULL OUT
INSULATION
PLUG

CHAMBER
FILL PORT

TOP

CHAMBER

SIDE

NO PROPYLENE GLYCOL
IN RESERVOIR FILL PORT!

REAR VIEW

Figure 2-2

2.3.2 Positioning & Connections

Reference Drawings 91D25901, 09S25920, 91S25921, 98D25919 & 98D25925

2.3.2.1 Pneumatic Cart

Position the 2500 humidity generator on the cart (figure 2-3 & 2-4), with the cart push bar on
the left side of the generator, placing the leveling feet within the circular cutouts. Connect the
short air supply hose to the generator air supply inlet.

STANDARD COMPRESSOR

Remove the air compressor shipping strap. For operation, place the air compressor on
the floor and connect the 25 foot (7.62m) air supply hose between the air compressor
outlet and the cart air supply inlet.

FRONT

BACK

Figure 2-3

2-3

G1

AT1

BV1

FRONT

RIGHT SIDE

REG

F2
F1

BV2

BACK

DV

LEFT SIDE

ACS

AH1

AH2

SOUND ENCLOSED COMPRESSOR (Optional)

Remove the sound enclosed air compressor shipping strap. For operation, the sound
enclosed air compres sor may be left on the cart and connected to the cart air supply
inlet with the short air hose attached to it or may be set on the floor and connected
using the 25 foot (7.62m) air supply hose between the sound enclosed air compressor
outlet hose and the cart air supply inlet.

Figure 2-4

2.3.2.2 Bench Space

Position the 2500 humidity generator allowing at least 4 inches (102mm) of space near
console air intake (l eft si de), and 4 inches (102mm) at the rear of the console for the exhaust
fan. Allow as much space as possible on the right side so as to allow clearance for utilizing
the chamber access port and to allow for opening of the chamber door. Level the console
using the top as a reference. Tighten leveling leg locking nuts against frame.

2.3.2.3 Power

Be sure the main console Power switch is OFF, then plug the 2500 into a source of 120
VAC/60Hz or 100 VAC/50 Hz at 15 amps minimum (240 VAC/60 Hz or 220 VAC/50 Hz at
10 amps minimum for HV option). If using the pneumatic cart, plug the air compressor into a
source of switched 120 VAC/60Hz or 100 VAC/50 Hz at 8 amps minimum (240 VAC/60 Hz
or 220 VAC/50 Hz at 5 amps minimum for HV option).

2-4

2.3.2.4 Air Supply

Using a line size equal to or larger than 1/4" (6.35mm) OD, connect a source of clean, oil
free, instrument quality air (refer to 2.2.3) to the 1/4" FPT fitting located at the lower rear of
the console (working pressure is 175 PSIG). If the generator is installed on the pneumatic
cart, but an alternate air supply (facility) is desired, connect the alternate air supply (175 PSIG
MAWP) to the air inlet of the cart air supply so as to utilize the valves, storage tank, filter,
and 150 PSIG regulated output of the pneumatic cart (figure 2-5).

G1
AT1
BV

REG
F2
F1

FRONT

AIR INLET

BACK

RIGHT SIDE

DV

LEFT SIDE

Figure 2-5

2-5

Section 3

SetPnt Actual

%RH @Pc 50.25

CHNG

CHNG

EDIT

RUN

OPERATION

3.1 GENERAL

At this point, all positioning and preparation of the Series 2500 humidity generator should
have been performed.

3.2 STANDARD OPERATING PROCEDURES

3.2.1 Power-Up

A) Verify that the air supply connection has been made, that power has been applied to
the air compressor, and that the air supply is pressurized. Open the On/Off valves, if
installed, in this supply line.

B) Verify that primary AC power is connected to the console and is switched ON.

C) Toggle the Power switch located at the lower right rear of console to ON. The liquid
crystal display will light, a banner will appear, and the generator will perform a very short
diagnostics test.

3.2.2 Control/Display Screen

At the end of the power-up sequence, the following Control/Display Screen appears.

All control and measurement parameters critical to the operation of the humidity generator
are displayed on this screen. Notice that in the left most column, each parameter is identified
with a brief title and corresponding units. The generator operates in a variety of temperature,
pressure, and flow units (section 3.2.4). Humidity is calculated and displayed in percent
Relative Humidity (%RH). The asterisk in the left most column indicates the active humidity
control parameter (section 3.2.5). The reservoir fluid level is graphically indicated and
continually updated in the lower right hand corner (section 3.2.9).

*%RH @PcTc 50.00

SATUR Psi 29.40
CHMBR Psi

SATUR
CHMBR

FLOW l/m 20.00

o

C 25.00

o

C

3-1

SETP

UNIT

/CAL

The "SetPnt" column lists control setpoints used as a target value in order to control these
parameters. Only those parameters which the generator directly controls have values listed in
this column. For instance, since the 2500 has no control over the chamber pressure, that
parameter has no value listed in the "SetPnt" column.

The "Actual" column lists all of the measured data and calculated parameters of the
generator.

A description of each of the Control/Display parameters follows:

%RH @Pc - The %RH calculated at the chamber pressure Pc. This calculation ignores

the chamber temperature and Effective Degree of Saturation (section 1.2.5),
and assumes that the chamber is at saturation temperature. The humidity
%RH @ Pc is calculated from the Pressure Ratio (section 1.2.4) and
Enhancement Factor Ratio (section 1.2.6), resulting in

%RH @ Pc =

P

P

c

•

s

ƒ

ƒ

Ps,Ts

Pc,Ts

•100

Note that the enhancement factor for the chamber (the numerator of the

Enhancement Factor Ratio) is calculated using saturation temperature rather
than chamber temperature.

%RH @ PcTc - The %RH calculated at the chamber pressure Pc and chamber temperature

Tc relative to saturation temperature Ts. This is the most accurate
calculation of %RH at the point in the immediate vicinity of the chamber
temperature probe. Placing the chamber temperature probe at the humidity
sensing point of devices under test gives the actual value of the relative
humidity being imposed on the devices, as it is dependent on both pressure
and temperature.

Viewing the difference between %RH @Pc and %RH @PcTc gives a good

indication of the gradient which exists between the humidity at the walls of
the chamber (since they are at saturation temperature) and the humidity at
the chamber temperature probe. The humidity %RH @PcTc is calculated
from the formula

%RH @PcTc =

P
P

c

•

s

ƒ

ƒ

Ps,Ts

Pc,Tc

•

e

s

•100

e

c

Note that this formulation utilizes the Pressure Ratio (section 1.2.4), the

Effective Degree of Saturation (section 1.2.5), and the Enhancement Factor
Ratio (section 1.2.6) found in equation 3 of section 1.2.3. Note also that the
enhancement factor for the chamber (the numerator of the Enhancement
Factor Ratio) is calculated using chamber temperature.

SATUR xxx - The saturation pressure measurement, Ps, may be displayed in units of bar,

mb, Tor, kPa, "Hg, or psi. Various humidity values are generated by
controlling the saturation pressure.

CHMBR xxx - The chamber pressure measurement, Pc, may be displayed in units of bar,

mb, Tor, kPa, "Hg, or psi. The chamber is designed to operate at ambient
barometric pressure only.

3-2

SATUR °X - The temperature of saturation, Ts, as measured by the saturation fluid

SetPnt Actual

%RH @Pc 50.25

temperature probe. Saturation temperature is used in the calculation of
%RH @PcTc, and is used to control the temperature of the fluid surrounding
the saturator and chamber. Temperatures may be displayed in °C or °F.

CHMBR °X - The temperature of the chamber, Tc, as measured by the chamber

temperature probe. Chamber temperature is used in the calculation of %RH
@PcTc. The chamber temperature probe should be placed as close as
practicable to the humidity sensing element of any device under test.
Chamber temperature typically lags behind the saturation temperature during
excursions away from ambient. Temperatures may be displayed in °C or °F.

FLOW xxx - The mass flow rate displayed in units of L/min, L/h, cfm, or cfh. This

parameter is not used in the calculation of humidity and is only an indication
of the amount of gas flowing through the system. This parameter is used
when performing tests on flow sensitive humidity measurement devices such
as aspirated psychrometers, chilled mirrors, etc.

3.2.2.1 Changing the Display Contrast

To increase the display contrast, press the <1> key repeatedly on the numeric keypad. To
decrease the contrast, press the <0> repeatedly. The new contrast setting is automatically
remembered by the system.

3.2.3 Changing Setpoints

After the initial power-up sequence of section 3.2.1, the Control/Display screen appears. At
the right of the display are 4 rectangular function key menu options. These labels correspond
to the four blank keys on the left side of the numeric keypad.

To change any of the RH, pressure, temperature, or flow setpoints, press the [CHNG SETP]
key. The menu labels then change to arrows.

A cursor block will begin flashing in the "SetPnt" column on the first digit of the current
humidity control parameter (the one with the asterisk to the left). Move the cursor up, down,
left, or right using the appropriate arrow key.

*%RH @PcTc 5_0.00

SATUR Psi 29.40
CHMBR Psi

SATUR
CHMBR

FLOW l/m 20.00

o

C 25.00

o

C

3-3

To change any (or all) of the setpoints, position the cursor over the desired setpoint, then edit
the value using the numeric keypad. Continue using the arrow keys and the numeric keypad
until all desired values have been changed.

End the setpoint editing session by pressing the <ENTER> key on the numeric keypad. The
arrow keys revert back to their previously displayed functions, and the setpoints are validated
and updated.

Example: Change the setpoints to 30%RH @PcTc at a temperature of 22.00 °C (or

71.60 °F)

A) Press [CHNG SETP]. The key labels change to arrows, and the cursor begins

flashing.

B) Using the arrow keys and numeric keys as necessary, make the %RH @PcTc setpoint

value on the screen appear as "30.00".

C) Move the cursor down to the SATUR °X setpoint value. System (chamber)

temperature is always changed from this saturation temperature setpoint.

D) Using the arrows and numeric keys as necessary, make the SATUR °X setpoint value

appear as "22.00" if the system is in °C or "71.60" if the system is in °F.

Note: To enter a negative temperature on systems equipped with this

option, press the left arrow key until the negative sign appears,
then enter the desired temperature.

E) Find the asterisk in the left most column of the display. If it is not next to the %RH

@PcTc label, use the arrow keys and position the cursor back at the %RH @PcTc
setpoint value. This indicates the humidity parameter used as the active control
setpoint (see section 3.2.5).

F) Press the <ENTER> key. The cursor disappears, and the displayed labels revert back

to their previous descriptions. There should also be an asterisk left of the %RH
@PcTc line label.

Setpoints within legal limits are accepted. Those setpoints which are slightly above or below
these limits are simply replaced by the appropriate limit value. Those setpoints which are far
beyond the limits revert back to the previous setpoint value and are accompanied by a short
audible warning beep. This most often occurs when the user inadvertently enters a wrong
value, or fails to include a decimal point.

Note: Always take note of the units when changing setpoints. All

setpoints must be entered in the units currently displayed on the
screen.

3-4

3.2.4 Changing Units

SetPnt Actual

%RH @Pc 50.25

PRES

TEMP

FLOW

The generator can operate in a variety of user selectable pressure, temperature, and flow
units.
To change units from the main control screen:

A) Press the [CHNG UNIT] key. The menu labels change to indicate the currently selected

pressure, temperature, and flow units.

*%RH @PcTc 50.00

SATUR Psi 29.40
CHMBR Psi

SATUR
CHMBR

FLOW l/m 20.00

o

C 25.00

o

C

Psi

o

C

l/m

B) Press [PRES] to select from psi (pounds per square inch), "Hg (inches of mercury), Tor

(Torr), bar (bars), mbar (millibars), and kPa (kilopascals) units of pressure.

C) Press [TEMP] to select from °C (degrees centigrade) and °F (degrees fahrenheit) units of

temperature.

D) Press [FLOW] to select from L/min (liters per minute), L/h (liters per hour), cfm (cubic

feet per minute), and cfh (cubic feet per hour) units of flow.

E) Press <ENTER>to return to the main control screen.

3.2.5 Control Modes

The generator has the ability to control the humidity in one of three possible modes.

Mode 1) %RH @Pc is held constant even under varying conditions of saturation

and chamber temperature. The saturation pressure tracks at a fixed
ratio above the chamber pressure. %RH @PcTc and SATUR xxx
setpoints vary under computer control.

Mode 2) %RH @PcTc is held constant by varying saturation pressure to

compensate for changes in chamber (barometric) pressure, and
differences between the saturation and chamber temperatures. This is
considered to be the most accurate RH calculation. %RH @Pc and
SATUR xxx setpoints vary under computer control.

Mode 3) SATUR xxx (saturation pressure) is controlled at a constant value

independent of chamber pressure, chamber temperature, or saturation
temperature. %RH @Pc and %RH @PcTc setpoints vary under
computer control.

3-5

The active control mode setpoint remains constant, while the two inactive mode setpoints

SetPnt Actual

%RH @Pc 50.25 50.26

CHNG

CHNG

PRNT

STOP

vary under computer control with changes in measured temperatures and pressures.

Mode 2 (%RH @PcTc) is the most often used and is the power-up default mode of the
generator. The currently active mode is indicated on the display by an asterisk to the left of
the parameter. Also, when a setpoint change is initiated, the cursor always begins flashing on
the current control mode parameter.

To change the control mode:

A) Press [CHNG SETP] to enter the setpoint editing mode.

B) Position the cursor on the desired control parameter.

C) Change its value if needed.

D) With the cursor still on that parameter, press <ENTER>. The asterisk will then

appear next to the selected control mode parameter.

Any time that a setpoint editing session is terminated (by pressing <ENTER>), AND the
cursor is on one of the three control mode parameters, that control mode becomes active. If
the cursor is on a non-control mode parameter (i.e., FLOW xxx, SATUR °X, etc.), the current
control mode remains in effect. An altered setpoint for a non-active control parameter that is
not made the active control mode will not remain as a valid setpoint.

3.2.6 Run/Stop

When the [RUN] key is pressed, the temperature, pressure, and flow control processes begin.
The fluid circulation pump will start and if the system requires cooling, the refrigeration
compressor will energize. The [RUN] key then toggles to [STOP].

The 2500 will generate the values of humidity, temperature, and flow indicated in the
"SetPnt" column. Setpoints and units may be freely changed regardless of whether the
generator is RUNNING or STOPPED (reference section 3.2.3/3.2.4). The values in the
"Actual" column are the actual measured values, and begin updating every 1.5 seconds.

*%RH @PcTc 50.00 50.01

SATUR Psi 24.23 24.20
CHMBR Psi 12.11

SATUR
CHMBR

FLOW l/m 20.00 19.74

08/10/12 12:40:04

o

C 25.00 25.00

o

C 25.13

3-6

SETP

UNIT

OFF

Pressing [STOP] causes the computer to perform a system shutdown and consists of the
following actions:

a) Pressure bleed solenoid valve opens.
b) Fluid circulation pump and refrigeration compressor stop.
c) Flow and Expansion valves close.
d) All control is disabled.

Once shutdown is completed the generator is left in an idle mode.

3.2.7 Printer (optional)

Reference Drawing 91D25915

An optional printer is used for hardcopy output of system data and other parameters. While
the 2500 humidity generator is operating, data is output on a timed interval basis when
activated by the user. User alterable printer parameters are explained in section 3.3.2.6. The
printer is connected using either a factory supplied or user made cable. Data will be printed
in the currently selected units.

The [PRNT OFF] key, when pressed, toggles to [PRNT ON] and causes measured system
data to be sent to the printer at regular time intervals (see section 3.3 to change default time
and other print parameters).

The [PRNT ON] key, when pressed, toggles to [PRNT OFF], disables printer output, and
sends a form feed command to the printer.

The <•> key, when pressed, immediately sends one line of system data to the printer
regardless of the PRNT ON/OFF status, and independent of print time interval.

Using this same procedure with a PC connected to the printer port instead of a printer, data
can be stored on the PC in a text file for later manipulation and printing. For instructions on
how to connect and use this option, refer to Section 4.2.5.

3.2.8 Power-Off

Power-Off refers to actually removing power and/or utilities from all or part of the humidity
generator. Before disconnecting primary power, a shutdown should be performed. If the
generator is currently RUNNING, press the [STOP] key.

If the generator is run on a daily basis, the system may be left idle with the power switch ON
so as to maintain the electronics at approximate operating temperature. If complete system
shutdown is to be performed, press the main rear panel Power switch to OFF. All functions
of the 2500 generator will shut off.

3-7

3.2.8.1 Maintenance Power-Off

Before maintenance of any kind, other than calibration, the following must first be
performed:

A) Press [STOP], if system is currently RUNNING, to close all

valves and disable control.
B) Press main rear panel Power switch to OFF.
C) Disconnect console from primary power.
D) Shut off and/or disconnect air supply.

3.2.9 Filling the Reservoir

The reservoir level is graphically displayed on the control/display screen by the computer
control system. When the level displayed is empty or prior to a long term test the reservoir
should be filled. The 2500 humidity generator holds approximately one gallon of distilled
water which can last from 12 hours to over 9 months of continuous use, depending on the
temperature and humidity at which it is operated (reference section 1.6.5)

Note: Reservior/presaturator system has been EMPTIED by factory

prior to shipment.

To fill the reservoir:

A) Press [STOP], if the generator is running, and allow all pressure to be vented.

B) Remove the reservoir fill port cap located on the top left panel of the system.

C) Add up to 1 gallon (3.8 liters) of double distilled water until the indicator on the

front panel reads full. Use the reservoir fill funnel or a small funnel may be

useful. Add the distilled water slowly so as not to overfill the reservoir.

D) Replace fill port cap, finger tighten, and proceed with operation.

3-8

3.3 EDITING SYSTEM COEFFICIENTS AND PARAMETERS

CAL

EDIT

PRNT

DONE

ENTER AUTHORIZATION CODE

CAL

EDIT

PRNT

DONE

All of the calibration coefficients and system parameters may be viewed and/or edited by the
operator. The following is a summary of items that may be edited.

Temperature Probe Calibration Coefficients

Pressure Transducer Calibration Coefficients

Flow Transducer Calibration Coefficients

Probe and Transducer Averaging

Serial Port Baud Rates, Parity, etc.

Print Interval and Lines Per Page

Time and Date

3.3.1 Edit Mode

The EDIT mode is used for the viewing and editing process.

1. From the Control/Display screen, press [EDIT/CAL]. Note, for this menu option to
appear, the generator must not be RUNNING. In a few seconds, the following menu
appears.

REPT

2. From the menu, press [EDIT].

3. At the prompt, enter in your authorization code (found at the back of the manual).

[~ ]

REPT

3-9

An incorrect code prevents access and returns to step 3. A correct code results in the

SATURATION TEMP, Ts

EDIT

NEXT

PREV

DONE

MASS FLOW RATE

EDIT

NEXT

PREV

DONE

MASS FLOW RATE

+ +

'E'

display of calibration coefficients.

Zero [-.0851657 ]
Span [ .0200085 ]
Lin [ 4.85408E-09 ]
Avg [ 10 ]

Last Cal Date 08/10/12

4. Using the [NEXT] and [PREV] keys, view any or all of the remaining coefficient and
parameter screens.

5. To edit a particular displayed value, press [EDIT]. The cursor begins flashing at the left
of the first parameter displayed.

Using [±±], ['E'], arrow keys, and the numeric keys as necessary, change any or all
displayed values as desired. Then press <ENTER>.

6. After Editing or Viewing, press [DONE]. Then from the next menu, press [DONE]
again. The system reinitializes back to the Control/Display screen.

Zero [ 0 ]
Span [ 1.6E-3 ]
Lin [ 0 ]
Avg [ 10 ]

Last Cal Date 08/10/12

- -

Zero [~0 ]
Span [ 1.6E-3 ]
Lin [ 0 ]
Avg [ 10 ]

Last Cal Date 08/10/12

3-10

3.3.2 Coefficients and Parameters

SATURATION TEMP, Ts

EDIT

NEXT

PREV

DONE

Each of the values on the various coefficient and parameter screens will be discussed in detail
in the following sections.

3.3.2.1 Temperature Coefficients

Zero [-.0851657 ]
Span [ .0200085 ]
Lin [ 4.85408E-09 ]
Avg [ 10 ]

Last Cal Date 08/10/12

The ZERO, SPAN, and LIN values are coefficients to the formula

Temp = A + Bx + Cx

2

where A = zero coefficient
B = span coefficient
C = linearity coefficient
x = output of the STD-A/D converter board.

These coefficients are automatically computed during temperature calibration (section 4.2.2).

AVG is the amount of averaging applied to the displayed value. Averaging is applied with
the formula

New Value = {(Previous Value *AVG) + New Reading}/(AVG + 1)

An AVG of zero (0) effectively eliminates averaging. An AVG which is very large has a
correspondingly large averaging affect. Non-integer averaging amounts are allowable;
however, negative amounts should never be used. An AVG of approximately 10 is typical,
while an AVG of 1000 would be excessively high.

The date indicated at the bottom of the screen is the last date of calibration or the date of the
most recent editing of any of the listed values. The date shown may not be edited and is
updated automatically during calibration or when changing coefficients on this screen.

3-11

3.3.2.2 Reference Resistor Coefficients

LOW RANGE PRESSURE, Pc, Ps

EDIT

NEXT

PREV

DONE

These coefficients are similar to the temperature coefficients of section 3.3.2.4. The

reference resistor is approximately 10KΩ, and the coefficients are chosen to provide a

reference value of approximately 0 °C. An AVG amount of approximately 50 is typical.

Any change made to either the reference resistor or the coefficients (with the exception of
AVG) requires that the temperature calibration of section 4.2.2 be performed on all four
probes.

3.3.2.3 Pressure Coefficients

Zero [ .012944 ]
Span [ 4.98212E-03 ]
Lin [ 1.09224E-09 ]
Avg [ 10 ]

Last Cal Date 08/10/12

The ZERO, SPAN, and LIN values are coefficients to the formula

Pressure = A + Bx + Cx

2

where A = zero coefficient
B = span coefficient
C = linearity coefficient
x = output of the STD-A/D converter board.

These coefficients are automatically computed during pressure calibration (section 4.2.3)

AVG is the amount of averaging applied to the displayed value. Averaging is applied with
the formula

New Value = {(Previous Value *AVG) + New Reading}/(AVG + 1)

An AVG of zero (0) effectively eliminates averaging. An AVG which is very large has a
correspondingly large averaging affect. Non-integer averaging amounts are allowable;
however, negative amounts should never be used. An AVG of approximately 10 is typical,
while an AVG of 1000 would be excessively high.

The date indicated at the bottom of the screen is the last date of calibration or the date of the
most recent editing of any of the listed values. The date shown may not be edited and is
updated automatically during calibration or when changing coefficients on this screen.

3-12

MASS FLOW RATE

EDIT

NEXT

PREV

DONE

3.3.2.4 Flow Coefficients

Zero [ 0 ]
Span [ 1.6E-3 ]
Lin [ 0 ]
Avg [ 10 ]

Last Cal Date 08/10/12

The ZERO, SPAN, and LIN values are coefficients to the formula

Flow = A + Bx + Cx

2

where A = zero coefficient
B = span coefficient
C = linearity coefficient
x = output of the STD-A/D converter board.

These coefficients are automatically computed during flow calibration (section 4.2.5)

AVG is the amount of averaging applied to the displayed value. Averaging is applied with
the formula

New Value = {(Previous Value *AVG) + New Reading}/(AVG + 1)

An AVG of zero (0) effectively eliminates averaging. An AVG which is very large has a
correspondingly large averaging affect. Non-integer averaging amounts are allowable;
however, negative amounts should never be used. An AVG of approximately 10 is typical,
while an AVG of 1000 would be excessively high.

The date indicated at the bottom of the screen is the last date of calibration or the date of the
most recent editing of any of the listed values. The date shown may not be edited and is
updated automatically during calibration or when changing coefficients on this screen.

3-13

3.3.2.5 Console Port Parameters

CONSOLE PORT PARAMETERS

EDIT

NEXT

PREV

DONE

These parameters affect the manner in which the bi-directional RS-232C Console Port
behaves. Changes become effective immediately.

Baud: 300, 600, 1200, 2400, 4800, 9600, 19200 or 38400 bits per second

Data: 7 or 8 bit word size.

Stop: 1 or 2 stop bits

Parity: 0 for NO parity, 1 for ODD parity, or 2 for EVEN parity

EOL: The ASCII value of the desired End-Of-Line or terminator character. Here, '13' is

the ASCII value for a Carriage Return.

Cancel: The ASCII value of the desired cancel-the-line character. Sending this character

clears anything in the input buffer of the Console Port. Here, '3' is the ASCII value
sent when executing a Control-C on most computers.

Caution:

It is advised that these settings stay at factory defaults.

The reason for keeping factory defaults is because the higher baud rates may cause overflow
and task overrun issues with the processor board.

Factory Default Settings:

Baud: 2400
Data: 8
Stop: 1
Parity: 0
EOL: 13
Cancel: 3

Baud [ 2400 ]
Data [ 8 ]
Stop [ 1 ]
Parity [ 0 ]
EOL [ 13 ]
Cancel [ 3 ]

3-14

3.3.2.6 Printer Port Parameters

PRINTER PORT PARAMETERS

EDIT

NEXT

PREV

DONE

DATE 08/10/12

EDIT

NEXT

PREV

DONE

These parameters affect the manner in which the unidirectional RS-232 Printer Port behaves.
It not only affects communication parameters, but time interval between printouts of system
data, and the number of lines to print per page.

Baud [ 9600 ]
Data [ 8 ]
Stop [ 1 ]
Parity [ 0 ]
Intrvl [ 60 ]
Lns/Pg [ 50 ]

Baud: 300, 600, 1200, 2400, 4800, 9600, 19200 or 38400 bits per second

Data: 7 or 8 bit word size.

Stop: 1 or 2 stop bits

Parity: 0 for NO parity, 1 for ODD parity, or 2 for EVEN parity

Intrvl: The print interval, or number of seconds between printouts of system data.

Lns/Pg: Lines per Page of printed data.

3.3.2.7 Time and Date

This screen is used to change the Time and/or Date of the Real Time Clock. Note that time is
input and displayed in military 24 hour format.

TIME 15:29:39

Month [ 08 ]
Date [ 10 ]
Year [ 12 ]
Hour [ 15 ]
Min [ 29 ]
Sec [ 39 ]

3-15

Section 4

CALIBRATION AND MAINTENANCE

4.1 GENERAL

The Series 2500 humidity generation system requires little periodic maintenance. Following
the proper operating procedures as given in this manual will help assure trouble-free
operation of this system.

4.2 CALIBRATION

Proper calibration of the temperature and pressure transducers is critical to the accuracy of
the generated humidity. Each time a transducer is calibrated its current calibration
coefficients and calibration data are stored to non-volatile memory. Although not critical to
system generation accuracy, the flowmeter coefficients and data are also retained in non­volatile memory.

Calibration of the system requires the following support equipment:

1) Temperature:

A. Temperature bath with a liquid medium (recommend Fluorinert, a 3M product), a

range of 0-70 °C, and stability of ±0.01 °C or better. Less stable baths may require
the use of a thermal block.

B. Standard or reference thermometer (PRT or Thermistor) for the range of 0-70 °C with

a resolution of 0.01 °C or better. Thermometer accuracy should be ±0.05 °C or better.

2) Low Pressure (0-50 PSIA):

A. Static gas pressure source for the pressure range of ambient to 50 PSIA with a

stability of ±0.0025 PSIA or better.

B. Standard or reference pressure gauge for the range ambient to 50 PSIA with a

resolution of ±0.0025 PSIA. Gauge accuracy should be ±0.025 PSIA or better.

3) High Pressure (50-150 PSIA):

A. Static gas pressure source for the pressure range of 50 to 150 PSIA with a stability of

±0.01 PSIA or better.

B. Standard or reference pressure gauge for the range of 50 to 150 PSIA with a

resolution of ±0.01 PSIA or better. Gauge accuracy should be ±0.10 PSIA or better.

4) Flow:

A. Standard or reference flowmeter for the range of 0 to 20 L/min with a resolution of

0.1 L/min or better. Flowmeter accuracy should be ±0.5 L/min or better.

4-1

Calibration of all transducers is to be performed "in the system, as a system". There are no
provisions for, nor do we recommend, calibration of any of the transducers (temperature,
pressure, or flow) while electrically disconnected from the generator. Since all calibration is
performed mathematically by the computer, there are no manual adjustments.

Calibration is performed on all of the transducers by solving for the coefficients A, B, and C
of the formula:

Y=A+Bx+Cx

2

where x is the raw count (or uncalibrated output of the A/D

converter) while measuring a transducer, and

Y is the desired value (the standard or reference

transducer's reading) for the transducer being calibrated.

The three coefficients A, B, and C are found by applying three separate, distinct, and stable
references to each transducer, then solving the mathematical system of three equations with
three unknowns. Since all of these calculations are performed automatically by the 2500's
embedded computer, the operator need only be concerned with providing three known stable
references required for the calibration of each transducer.

4.2.1 A/D Board (STD-A/D)

Equipment Required: (None)

All calibration errors appearing in the A/D board will be accounted for automatically during
calibration of the temperature, pressure, and flow transducers. The board is also equipped
with built in auto-zero and auto-span circuitry which automatically and continually accounts
for short and long term drift in measurement accuracy. No user calibration is required. A
board suspected of extreme inaccuracies or malfunctions should be sent to the factory for
repair.

4.2.2 Temperature Calibration

The systems EDIT/CAL mode may be used in conjunction with a precision temperature bath
for temperature probe calibrations. Any combination of one or more temperature probes may
be calibrated at any one time, leaving calibration of the remaining probes unaltered.

By using the temperature bath to generate three known temperatures, all coefficients (ZERO,
SPAN, LINEARITY) can be calculated automatically by the embedded computer and used to
update the system calibration. A new calibration report may also be printed at the conclusion
of the calibration sequence.

Equipment Required:

1. Temperature Bath (per section 4.2).

2. Standard or Reference thermometer (per section 4.2)

3. 7/16" open end wrench

4. Needle nose pliers

5. #10 Torx driver

4-2

4.2.2.1 Temperature Calibration Procedure

Reference Drawing 91D25902

1) Switch main console power OFF.

2) Turn OFF or disconnect the air supply.

CAUTION!

ALL SYSTEM PRESSURE MUST

BE VENTED BEFORE

PROCEEDING.

3) Using a #10 Torx driver, remove both top panels and the left rear panel from the
generator. Remove the black foam insulation blocks and plugs from the openings.

4) Remove temperature probes to be calibrated.

Notes:

(A) Remove the Chamber Temperature Probe by pulling the rubber cork

and feeding the probe and cable through the chamber jacket opening.

(B) Before removing the Saturation Temperature Probe (RTD0), two

gallons of heat transfer fluid must be drained. Remove the fill cap
located on top of chamber. Locate the drain hose at bottom rear of
console. Remove cap and drain the chamber fluid. Be sure to save
fluid for refilling. Using the 7/16" wrench, remove the saturation
temperature probe.

(C) Using the 7/16" wrench, remove the Presaturator Temperature Probe

(RTD1) if desired.

(D) To gain access to the Expansion Valve Temperature Probe (RTD2),

remove the foam insulation blocks from the expansion valve and drive
assembly. Using needle nose pliers, loosen the knurled compression
nut which holds the temperature probe. Gently slide the probe out,
leaving the knurled nut assembly in place.

(E) Feed the temperature probes to be calibrated through the inside panel

grommet and uncoil the cables.

5) Bring a precision temperature bath with reference thermometer to the system, and
install thermistors to be calibrated into temperature bath.

6) Switch main console power ON. Wait a few moments for the system to initialize and
for the Control/Display screen to appear.

4-3

CAL

EDIT

PRNT

DONE

TEMP

PRES

FLOW

DONE
Count Deg C

_Satur Tmp

MARK

EXIT

OK

7) Press the [EDIT/CAL] key. The Edit/Cal menu appears.

REPT

8) Press the [CAL] key. The calibration menu appears.

CAL

CAL

CAL

9) Press the [TEMP CAL] key. The probe selection screen appears.

/CLR

PrSat Tmp
Expan Tmp
Chamb Tmp
Refer Tmp

QUIT

10) Using [MARK/CLR] and the down arrow key as necessary, mark the probes to be
calibrated. A marked probe is indicated with an asterisk on the left. (Note that the
"Refer Tmp" cannot be marked and is displayed for reference only.)

4-4

11) Once the desired probes are marked, press [OK]. The LOW, MID, and HIGH

Count Deg C

*Satur Tmp 1180 23.41

LOW

MID

HIGH

EXIT
Count Deg C

*Satur Tmp 183 3.446

++

OOPS

temperature reference values appear at the bottom of the screen, and within a few
seconds, actual data begins updating in the "Count" and "Deg C" columns.

TEMP

*PrSat Tmp 1165 23.12
*Expan Tmp 1173 23.20
*Chamb Tmp 1155 23.08
Refer Tmp 1257 .1364

Low Mid High

0 35 70

TEMP

TEMP

QUIT

12) Adjust the temperature bath to a LOW temperature point at or near 0 °C and allow
sufficient time for stability.

13) Once stable, press [LOW TEMP], and input the value of the Standard Thermometer
as the LOW temperature. Use [±±] and arrow keys as necessary.

--

*PrSat Tmp 167 3.143
*Expan Tmp 173 3.228
*Chamb Tmp 157 3.101
Refer Tmp 1257 .1476

Low Mid High

3.16 _ 35 70

Then press <ENTER>. The LOW temperature value just entered, and the values of
each of the marked probes are automatically saved to memory for future computation
of calibration coefficients.

Note: If a mistake was made during the temperature entry mode, use

[OOPS] rather than <ENTER>. This will cancel the temperature
entry mode and restore the previous "standard" and "marked"
probe values to memory. For instance, [OOPS] could be used if
the operator wanted to take the LOW temperature point, but had
mistakenly pressed the [MID TEMP] key.

4-5

14) Repeat step 13 for both a MID temperature (near 35 °C) and HIGH temperature (near

SATURATION TEMP, Ts

PRNT

VIEW

EXIT

SAVE

70 °C). Be sure to use the appropriate [MID TEMP] and [HIGH TEMP] keys.

Note: Using the LOW TEMP, MID TEMP, or HIGH TEMP key more

than once allows the previous point of each thermistor to be
over-written with the most current measured value. The
reference thermometer value will also be over-written with the
new value entered. The data stored is that which exists on the
screen in the "Count" column when the LOW TEMP, MID
TEMP, or HIGH TEMP key is pressed.

15) After all three temperature points have been taken; press [CALC COEF] to calculate
the new temperature coefficients for those probes which are marked. Unmarked
probes retain their previous coefficients. The current coefficients for one probe will
appear on the screen. Use the [VIEW NEXT] key to display coefficients for the other
probes.

COEF

16) Press the [PRNT COEF] key if a printout of the coefficients is desired.

17) To update the calibration with new coefficients, press the [SAVE QUIT] key. To
abort without storing these new coefficients, press the [EXIT QUIT] key.

18) Check the accuracy of the calibration if desired, by repeating steps 9 through 12,
however, don't "mark" any of the probes for calibration. Adjust the temperature bath
to any values between 0 and 70 °C and visually compare readings.

19) Switch main console power OFF.

20) Re-install all temperature probes. Tighten all connections just past finger tight.

21) Cap the chamber fluid drain valve and refill the chamber fluid jacket with the
water/glycol mixture which was removed in step 4(B).

22) Replace all covers and panels. The system must not be operated unless ALL panels
are in place.

23) To print a calibration report, refer to section 4.2.5.

Zero [-.0851657 ]
Span [ .0200085 ]
Lin [ 4.85408E-09 ]

EXIT

QUIT

QUIT

Note: If the new coefficients were printed but not SAVED, the new

coefficient values may be entered using the EDIT mode
described in section 3.3.1.

4-6

4.2.3 Pressure Transducer Calibration

Pressure Transducer Calibration is typically performed in a calibration laboratory and
requires that the transducers be removed from the pneumatic system of the 2500, but must
remain electrically connected. The pressure readings must be precise in order to retain
accurate relative humidity calculations.

Equipment Required:

1. Static pressure source, range ambient to 50 PSIA (per section 4.2).

2. Static pressure source, range 50 to 150 PSIA (per section 4.2).

3. Standard or reference pressure gauge, range ambient to 50 PSIA (per section 4.2).

4. Standard or reference pressure gauge, range 50 to 150 PSIA (per section 4.2).

5. 9/16" and 11/16" open end wrenches.

6. #10 Torx driver.

7. Flat blade screw driver.

4.2.3.1 Pressure Calibration Procedure

1) Switch console power OFF.

2) Turn OFF or disconnect air supply.

CAUTION!

ALL SYSTEM PRESSURE MUST

BE VENTED BEFORE

PROCEEDING.

3) Bring the pressure source to the generator or take the generator to the pressure

calibration lab.

4) Using a #10 Torx driver, remove top left console panel.

5) Disconnect pressure transducers (11/16" & 9/16" wrench required). Using a

screwdriver, pry open the round snap-lock transducer mounts, and remove the
transducers. Ensure the electrical connectors are in place.

6) Connect the pressure source to the transducer to be calibrated (one only).

Note: Each transducer is operated over a limited range and requires

calibration within this range only.

a) 0-50 PSIA Transducer - Calibrate from ambient to 50 PSIA.
b) 0-150 PSIA Transducer - Calibrate from 50 to 150 PSIA.

4-7

7) Switch console power ON. Wait a few moments for the softkey menu to appear.

TEMP

PRES

FLOW

DONE
Count PSIA

*_Low Range

MARK

EXIT

OK
Count PSIA

*Low Range 2445 12.18

LOW

MID

HIGH

EXIT

Allow approximately 30 minutes or more for warm-up of the pressure transducer
electronics.

8) Press the [EDIT/CAL] key, then the [CAL] key. The calibration menu appears.

CAL

CAL

CAL

9) Press the [PRES CAL] key.

10) Using [MARK/CLR] and the down arrow key as necessary, mark the transducer to be
calibrated. A marked transducer is indicated with an asterisk in the left most display
column. Since the two transducers require different calibration ranges, the computer
will only allow you to mark one transducer at a time.

/CLR

High Range

QUIT

11) Press [OK], or if a mistake was made, press [EXIT QUIT]. [EXIT QUIT] reverts to
step 9.

PRES

High Range 818 12.19

Low Mid High

10 30 50

PRES

PRES

QUIT

4-8

12) Apply the lower recommended calibration pressure and watch the displayed value.

Count PSIA

*Low Range 2444 12.18

++

OOPS
Count PSIA

*Low Range 6028 30.11

++

OOPS
Count PSIA

*Low Range 10021 49.92

++

OOPS

Once stable, press the [LOW PRES] key and enter the reference pressure. Then press
<ENTER>.

--

High Range 817 12.18

Low Mid High

12.214_ 30 50

Note: For the low range transducer, ambient pressure should be used

for the low pressure calibration point.

Note: If a mistake is made during reference pressure entry, pressing the

[OOPS] key cancels the data entry mode, leaving all values
unchanged.

13) Apply the mid range pressure and watch the displayed value. Once stable, press the
[MID PRES] key and enter the reference pressure. Then press <ENTER>.

--

High Range 816 12.17

Low Mid High

12.214 29.989_ 50

14) Apply the upper recommended pressure and watch the displayed value. Once stable,
press the [HIGH PRES] key and enter the reference pressure. Then press <ENTER>.

--

High Range 816 12.17

Low Mid High

12.214 29.989 49.904_

4-9

Count PSIA

*Low Range 10021 49.92

LOW

PRES

MID

HIGH

CALC

LOW RANGE PRESSURE, Pc, Ps

PRNT

VIEW

EXIT

SAVE

High Range 817 12.16

Low Mid High

12.214 29.989 49.904

PRES

PRES

COEF

15) Press the [CALC COEF] key. All coefficients for the marked transducer will be
calculated, and those of the low range transducer will appear first on the LCD display.

COEF

Zero [ .014394 ]
Span [ 4.98212E-03 ]
Lin [ 1.09224E-09 ]

NEXT

QUIT

QUIT

16) Press [VIEW NEXT] to view the coefficients of the other transducer if desired.

17) To obtain a printout of the new coefficients, press [PRNT COEF].

18) To save the coefficients, press [SAVE QUIT]. The coefficients will be stored to non­volatile memory. To abort the calibration without saving the coefficients just
calculated, press [EXIT QUIT]. The previous coefficients will be reinstated.

19) At the calibration menu, press [DONE]. Then press [DONE] at the next menu. The
system reinitializes and the Control/Display screen appears.

20) Repeat steps 9 thru 19 for the second pressure transducer.

21) Switch main console power to OFF.

22) Re-install the pressure transducers (0-50 PSIA transducer T2 is on top). Tighten all
connections 1/4 turn past finger tight.

23) Replace top left console panel. The system must not be operated unless all panels are
in place.

24) To print a calibration report, refer to section 4.2.5.

4-10

4.2.4 Flow Transducer Calibration

CAL

EDIT

PRNT

DONE

TEMP

PRES

FLOW

DONE

The flow measurement, while indicated on the screen, is not critical to the accuracy of the
generated humidity and is not used in the humidity calculations. Flow calibration accuracy
depends upon the requirements of the user.

Equipment Required:

1. Standard or Reference flowmeter (per section 4.2).

4.2.4.1 Flow Calibration Procedure

The calibration for the flowmeter is slightly different than for the temperatures and pressures,
and does not require the removal of the flowmeter from the system.

1) Using appropriate fittings, connect a flowmeter reference instrument to the chamber

inlet port of the system.

2) Generate 10 liters per minute at approximately 10% RH at 21 °C. Once stable, note

the readings of the reference flowmeter and of the indicated flow of the 2500.

3) Change the flow to 20 liters per minute and note both readings again.

4) Press [STOP]. Once the shutdown is complete, press [EDIT/CAL]. The following

menu appears.

5) Press [CAL]. The calibration menu appears.

REPT

CAL

CAL

CAL

4-11

6) Press [FLOW CAL].

Count SLPM

*Mass Flow 4 .0144

++

OOPS
Count SLPM

*_Mass Flow

MARK

EXIT

OK
Count SLPM

*Mass Flow 4 .0144

LOW

MID

HIGH

EXIT

7) Press [MARK/CLR] to mark the flowmeter (indicated by an asterisk to its left).

/CLR

QUIT

8) Press [OK]. Within a few seconds, the measured flow readings begin updating.

FLOW

Low Mid High

0 10 20

FLOW

FLOW

QUIT

9) Allow a few moments for stability of the flow indication. This "no flow" condition
will be used for a LOW flow reference. Press [LOW FLOW] to store this point.
Then press <ENTER>.

--

Low Mid High

0_ 10 20

4-12

10) Using the 10 liter data obtained in step 2, calculate the following:

Count SLPM

*Mass Flow 5000 20

++

OOPS
Count SLPM

*Mass Flow 2500 10

++

OOPS

*Mass Flow 5000 20

Count SLPM

LOW

MID

HIGH

CALC

10+ (Reference Indication) - (2500 Indication)

Press [MID FLOW] and enter this calculated value.

--

Low Mid High

0 10.14 _ 20

11) Using the 20 liter data obtained in step 3, calculate the following:

20+ (Reference Indication) - (2500 Indication)

Press [HIGH FLOW] and enter this calculated value.

12) Press [CALC COEF] to calculate the new flowmeter coefficients.

Low Mid High

0 10.1 20.20 _

Low Mid High

0 10.1 20.20

--

FLOW

FLOW

FLOW

COEF

4-13

MASS FLOW RATE

PRNT

EXIT

SAVE

4.2.5 Printing the Calibration Report

If a printer is connected to the Printer Port, a report may be printed which lists the calibration
coefficients and calibration dates for the temperature, pressure, and flow transducers. The
report is printed from the Edit/Cal menu.

To print the report:

To save the report:

These new coefficients appear on the display.

COEF

Zero [ 0 ]
Span [ 1.6E-03 ]
Lin [ 0 ]

QUIT

QUIT

13) To obtain a printout of the new coefficients, press [PRNT COEF].

14) To save the coefficients to non-volatile memory, press [SAVE QUIT]. To discard
these new coefficients and revert to the previous ones, press [EXIT QUIT].

15) At the calibration menu, press [DONE]. At the next menu, press [DONE] again. The
system reinitializes to the Control/Display screen.

16) To print a calibration report, refer to section 4.2.5.

1) From the Control/Display screen press [EDIT/CAL], or from the Cal menu press
[DONE]. Both actions should bring up the Edit/Cal menu.

2) Ensure the printer is on, then press [PRNT REPT]. The Calibration Report will be
sent to the printer.

3) Press [DONE] to return to the Control/Display screen.

1) From the Control/Display screen press [EDIT/CAL], or from the Cal menu press
[DONE]. Both actions should bring up the Edit/Cal menu.

2) Using the computer cable supplied and a gender changer, connect a PC from its COM
port to the printer port of the 2500. Open the application “HyperTerminal” and
configure it to match the printer port parameters i.e. Baud, Data, Stop, Parity. Select
Capture Text from the Transfer menu and press [PRNT REPT] from the 2500 control
panel. When data output is finished, select Capture Text – Stop from the Transfer

4-14

menu. Where and when appropriate, open the file containing the Calibration Report
with WordPad. The last character in the file is a small square. Delete this. From the
File-Page Setup... menu, set all four margins to one (1) inch. Print the data from
within WordPad.

3) Press [DONE] to return to the Control/Display screen.

Note: System data may also be logged this way during normal system

generating mode, either with “Print On Demand” or timed
interval printing.

A sample of the calibration report follows:

4-15

Calibration Report

for

TSC Model 2500 Humidity Generator

S/N XXXXXXX
Date MM/DD/YY

Temperature Zero Span Linearity Cal Date

Saturation Temperature 0.00000E+00 1.00000E-02 0.00000E+00 MM/DD/YY
Presat Temperature 0.00000E+00 1.00000E-02 0.00000E+00 MM/DD/YY
Ex Valve Temperature 0.00000E+00 1.00000E-02 0.00000E+00 MM/DD/YY
Chamber Temperature 0.00000E+00 1.00000E-02 0.00000E+00 MM/DD/YY
Temp Reference Resistor -2.50000E+01 1.00000E-02 0.00000E+00 MM/DD/YY

______ ______ ______ ______ ______

Pressure Zero Span Linearity Cal Date

Low Range (0-50 psia) 0.00000E+00 2.00000E-03 0.00000E+00 MM/DD/YY
Hi Range (0-150 psia) 0.00000E+00 6.00000E-03 0.00000E+00 MM/DD/YY

______ ______ ______ ______ ______

Flow Zero Span Linearity Cal Date

Mass Flow Rate 0.00000E+00 1.60000E-03 0.00000E+00 MM/DD/YY

Certified by ________________________

Date ________________________

4-16

4.3 ROUTINE MAINTENANCE

4.3.1 Console Intake: Monthly

1) Locate console intake on left side of generating console.

2) Remove any dust and other obstructions.

4.3.2 Chamber Fluid Level: Yearly

1) Remove top right console panel.

2) Locate fluid fill cap on top of console (under black insulating foam).

3) Remove cap and check that the fluid is approximately 1/4" (6.35mm) below bottom of

fill port.

4) If fluid level is low, add distilled water as necessary.

5) Replace fluid fill cap and black insulating foam.

6) Replace console panel.

4.3.3 Pre-saturator Drain: Yearly

1) Turn main power ON and perform reservoir fill procedure (per section 3.2.9).

2) Turn main power switch OFF and remove power cord.

3) Remove left rear panel using a number 10 Torx tool.

4) Locate the Pre-saturator drain cap (Swagelok cap, to the left of the circulation pump).

5) Loosen (do not remove) the drain cap using a 9/16" wrench.

6) Prepare a 1/4" plastic drain tube, approximately 4’ to 6’ long, with a Swagelok nut and

ferrule assembly on one end.

7) Place the open end of the tube into a bucket and place the Swagelok nut assembly in

close proximity to the Pre-saturator drain cap.

8) Remove the Pre-saturator cap and quickly place a finger over the open fitting to stop

water flow then quickly remove your finger and insert the tube into the fitting.
Tighten Swagelok nut finger tight.

9) Allow Pre-saturator to drain.

10) Remove drain tube assembly and replace drain cap. Tighten 1/8 turn past finger tight.

11) Replace left rear panel.

12) Re-install power cord. Turn power switch ON.

13) Press “Run” at the front panel.

14) After initialization the screen will indicate “PreSat Filling”. If “PreSat Filling” times

out an error code 16 “PreSat Water Empty” will occur and an alarm will sound. If
this happens, switch the main power OFF and then back ON then press “Run” again.

Note: It may be necessary to repeat this step two or three times until the Pre-saturator is

full.

15) When the Pre-saturator is full press “Shutdown” and switch power OFF.

4.3.4 Mobile Pneumatic Cart: Daily

1) Drain condensation from pressure tank using drain valve on bottom.

2) Drain condensation from inline air filter sumps using drain valves on bottoms.

3) For air compressor maintenance please refer to bulletin ACS2520 “Installation,

Operation, Parts List and Maintenance” located in the back of this manual.

4-17

4.4 ERROR CODES and TROUBLESHOOTING

Prior to system start-up, and during humidity generation, the system monitors itself for errors
and sources of possible malfunction. When a catastrophic error occurs, the system
automatically shuts down, then alerts the operator with a visual flashing message and an
audible tone. The visual message displays the error number and a brief description of the
problem.

It is possible (in many cases probable) to have multiple errors occurring at one time. Under
these circumstances, the error codes simply add together algebraically, and all of the
associated messages are displayed in turn. Any error code greater than 16383 will be
displayed as a negative number. In this case, simply add 65536 to the displayed number to
calculate the appropriate code. While it is not necessary to understand the error code system,
it is important to write down the error code number exactly as it appears on the screen when
consulting the factory for technical support. Little can be done to ascertain the nature of the
problem without the exact error code.

4-18

The following is a list of error codes and a brief description of each.

ERROR CODE DESCRIPTION

1 Expansion Valve Not Closing

2 Flow Valve Not Closing

4 No Supply Pressure

8 Reservoir Needs Water

16 Presaturator Water Empty

32 Low Pressure Underrange

64 Low Pressure Overrange

128 High Pressure Underrange

256 High Pressure Overrange

288 Pressure Transducer Failure

320 Low Pressure Overrange (Saturation Pressure)

480 Pressure Transducer Misalignment

512 Saturation Temperature High/Low limit

1024 Presaturation Temperature High/Low limit

2048 Expansion Valve Temperature High/Low limit

4096 Chamber Temperature High/Low limit

8192 Temperature Reference High/Low limit

16384 Temperature Underrange

16896 Saturation Temperature Underrange

17408 Presaturator Temperature Underrange

18432 Expansion Valve Temperature Underrange

20480 Chamber Temperature Underrange

24576 Reference Temperature Underrange

-16384 Cabinet Temperature Overrange

-24576 Reference Temperature Overrange

-28672 Chamber Temperature Overrange

-30720 Expansion Valve Temperature Overrange

-31744 Presaturator Temperature Overrange

-32256 Saturation Temperature Overrange

-32768 Temperature Overrange

4-19

Error 1 - Expansion Valve Not Closing

This indicates that while attempting to close the expansion valve, the HOME position
limit switch closure was not detected. This could mean that either the valve is not
moving properly or the switch is mechanically or electrically malfunctioning.

Error 2 - Flow Valve Not Closing

This indicates that while attempting to close the flow valve, the HOME position limit
switch closure was not detected. This could mean that either the valve is not moving
properly or the switch is mechanically or electrically malfunctioning.

Error 4 - No Supply Pressure

This indicates that there is insufficient air supply pressure to continue. Check the air
supply (either in-house or the cart air supply). A malfunction of solenoid valve SOL1 or
solid state relay SSR5 may also cause this problem.

Error 8 - Reservoir Needs Water

The reservoir is empty and needs water. Fill with one (1) gallon of distilled water. This
error only occurs during startup, immediately after pressing the [RUN] key.

Error 16 - Presaturator Water Empty

The presaturator has run empty due either to an empty reservoir or a malfunctioning
filling system.

Error 32 - Low Pressure Underrange

The low range pressure transducer indicates a pressure below 10 PSIA or equivalent in
other pressure units. The most likely cause is a pressure transducer malfunction.

Error 64 - Low Pressure Overrange

The low range pressure transducer indicates a chamber pressure above 20 PSIA or
equivalent in other pressure units. One possible cause would be a malfunction of the
pressure select solenoid SOL5. This error may also indicate a low range pressure
transducer malfunction.

Error 128 - High Pressure Underrange

The high range pressure transducer indicates a pressure below 10 PSIA or equivalent in
other pressure units. The most likely cause is a pressure transducer malfunction.

Error 256 - High Pressure Overrange

The high range pressure transducer indicates a pressure above 165 PSIA or equivalent in
other pressure units. The most likely cause is a pressure transducer malfunction.

Error 288 - Pressure Transducer Failure

This indicates that a measurement error of greater than 10 PSIA, or equivalent in other
pressure units, was observed on one of the pressure transducers. Likely causes include
pressure transducer malfunction or failure of the pressure select solenoid SOL5.

4-20

Error 320 - Low Pressure Overrange

This indicates that a saturation pressure of greater than 60 PSIA, or equivalent in other
pressure units, was measured by the low range pressure transducer. Transducer
malfunction (either one or both) is likely.

Error 480 - Pressure Transducer Misalignment

The low and high range pressure transducer measurements disagree with each other by
more than 1 PSIA or equivalent in other pressure units, indicating an alignment problem.
The most likely cause is improper calibration or malfunction of one or both pressure
transducers.

Error 512 - Saturation Temperature High/Low limit

This error occurs only in combination with an Over/Underrange Limit. If combined with
error code 16384 Temperature Underrange, the saturation temperature is below -10 °C
(14 °F). If combined with error code -32768 Temperature Overrange, the saturation
temperature is above 90 °C (194 °F). The most likely cause is misalignment or
malfunction of the temperature probe.

Error 1024 - Presaturation Temperature High/Low limit

This error occurs only in combination with an Over/Underrange Limit. If combined with
error code 16384 Temperature Underrange, the presaturator temperature is below -5 °C
(23 °F). If combined with error code -32768 Temperature Overrange, the presaturator
temperature is above 100 °C (212 °F). The most likely cause is misalignment or
malfunction of the temperature probe.

Error 2048 - Expansion Valve Temperature High/Low limit

This error occurs only in combination with an Over/Underrange Limit. If combined with
error code 16384 Temperature Underrange, the expansion valve temperature is below

-10 °C (14 °F). If combined with error code -32768 Temperature Overrange, the
expansion valve temperature is above 100 °C (212 °F). The most likely cause is
misalignment or malfunction of the temperature probe.

Error 4096 - Chamber Temperature High/Low limit

This error occurs only in combination with an Over/Underrange Limit. If combined with
error code 16384 Temperature Underrange, the chamber temperature is below -10 °C (14
°F). If combined with error code -32768 Temperature Overrange, the chamber
temperature is above 100 °C (212 °F). The most likely cause is misalignment or
malfunction of the temperature probe.

Error 8192 - Temperature Reference High/Low limit

The temperature reference resistor indication has deviated significantly from its nominal
value of 0 °C (32 °F). This typically indicates a bad reference resistor, or a
malfunctioning STD-A/D converter board.

Error 16384 - Temperature Underrange

This error never occurs alone. It may only occur in combination with temperature
high/low limits to indicate that the error is a low limit rather than a high limit.

4-21

Error 16896 - Saturation Temperature Underrange

The indicated saturation temperature is below -10 °C (14 °F). Suspect misalignment or
malfunction of the saturation temperature probe.

Error 17408 - Presaturation Temperature Underrange

The indicated presaturation temperature is below -5 °C (23 °F). Suspect misalignment or
malfunction of the presaturator temperature probe.

Error 18432 - Expansion Valve Temperature Underrange

The indicated expansion valve temperature is below -10 °C (14 °F). Suspect
misalignment or malfunction of the expansion valve temperature probe.

Error 20480 - Chamber Temperature Underrange

The indicated chamber temperature is below -10 °C (14 °F). Suspect misalignment or
malfunction of the chamber temperature probe.

Error 24576 - Reference Temperature Underrange

The temperature reference resistor is below its nominal value of 0 °C (32 °F). This
typically indicates a faulty reference resistor or malfunctioning STD-A/D converter
board.

Error -16384 - Cabinet Temperature Overrange

The measured cabinet temperature is too high. Most likely causes include a blocked or
clogged intake vent on the left side of the unit, a blocked outlet at the back of the unit, or
a faulty fan.

Error -24576 - Reference Temperature Overrange

The temperature reference resistor is well above its nominal value of 0 °C (32 °F). This
typically indicates a faulty reference resistor or malfunctioning STD-A/D converter
board.

Error -28672 - Chamber Temperature Overrange

The indicated chamber temperature is above 100 °C (212 °F). Suspect misalignment or
malfunction of the chamber temperature probe.

Error -30720 - Expansion Valve Temperature Overrange

The indicated expansion valve temperature is above 100 °C (212 °F). Suspect
misalignment or malfunction of the expansion valve temperature probe.

Error -31744 - Presaturation Temperature Overrange

The indicated presaturation temperature is above 100 °C (212 °F). Suspect misalignment
or malfunction of the presaturator temperature probe.

4-22

Error -32256 - Saturation Temperature Overrange

The indicated saturation temperature is above 90 °C (194 °F). Suspect misalignment or
malfunction of the saturation temperature probe.

Error -32768 - Temperature Overrange

This error never occurs alone. It may only occur in combination with temperature
high/low limits to indicate that the error is a high limit rather than a low limit.

4-23

Section 5

ATB

1

Analog Terminal Board

ADP7409TB

C1 1 Refrigeration Compressor 100/50 & 115/60Hz

COMPR-110V/50HZ

C1*

1

Refrigeration Compressor 220v/50Hz

COMPR-220V/50HZ

CBS1

1

Circuit Breaker Switch 1-Pole

BTPWRSW-R

CBS1*

1

Circuit Breaker Switch 2-Pole

BTPWRSW-2

CC 1 Card Cage Assembly

D92A25013

CF1

1

6" Console Fan (120VAC)

MR2B3

CF1*

1

6" Console Fan (220-240VAC)

MR77B3

CON

1

Refrigeration Condenser, R-134A

BT-COND

EX1

1

2500 Evaporator Assembly

D92A25018

EX1***

1

ST Evaporator Assembly

D92A25018-ST

FB1

1

EMI Ferrite Suppression Core

FERCORE

FD 1 Refrigeration Filter/Drier

C-032-S

FP1

1

Fluid Pump 115V 50/60Hz

TE3MDHC

FP1*

1

Fluid Pump 230V 50/60Hz

TE3MDHC230

FP1***,**

1

Motor for 3MDHC 220V/50Hz

ST977899

FP1***,**

1

Pump Head for 3-MD-HC

ST581697

FP1***

1

Fluid Pump 230V 60Hz

ST3MDHC230/60

FS1

1

Fuse, 4 Amp, 250V Slow Blow

WK4062BK

FS2

1

Fuse, 4 Amp, 5x20, Slow Blow

GDC-4A

FS3

1

Fuse, Time Delay 3.15A

S506-3.15

FS3*

1

Fuse, Time Delay 1.6A

S506-1.6

G1 1 200 PSIG Pressure Gauge

G6X114

H1-2

2

Heater, Cartridge 250 W

L3A82

H3 1 Heater, Cartridge 500W 120VAC

N9N-1560

H3***

1

Heater, Cartridge 1000W 240VAC

N8A21

H4 1 5.2 Ohm Foil Heater

HK6020

H5 1 Heater, Kapton Foil (22 Ohm)

HK5161

H5***

2

Heater, Kapton Foil (22 Ohm)

HK5161

HLS1

1

Switch, 212 °F Thermostat

HLSW1

HLS2

1

Switch, 190 °F Thermostat Epoxy Coated

HLSW2-EPOXY

HLS3

1

Switch, 110° C Thermostat

THRMST110

KB 1 Membrane Overlay Panel (2500)

D91M25281

LCD

1

Liquid Crystal Display

DMF6104

LCD-INV

1

Display Inverter Board Assembly

D08A25045

LL1

1

Reservoir Liquid Level Board Assembly

D94A25051

PARTS LISTS

5.1 COMPLETE SYSTEM COMPONENTS

Find # Qty. Description Part Number

5-1

Find#

Qty

Description

Part Number

LL2

1

Pre-saturator Liquid Level Board Assembly

D92A00043

MB

1

Mother Board Back Plane Assembly

D92A25024

MOV1

3

Metal Oxide Varistor

MOV1

PLF1

1

Power Line Filter for BT

F1200BB03

PSAT

1

Pre-Sat/Heat Exchanger

D94A25048_01

PSAT*****

1

High Air Flow Pre-Sat

D94A25048-HAF

PT1

1

Tee, Purge 1/4” Union

S4-3

REG

1

Precision Pressure Regulator

REGNG200

RES

1

2500 Reservoir Assembly

D92A25015

RTD0,2,3

3

3" Thermistor Probe Assembly

BTPROBE3

RTD1

1

4" Thermistor Probe Assembly

THRMPB4

RV1

1

1/4" Adjust Relief Valve 150Psi

S4C-150

SAT

1

Pre-Sat/Heat Exchanger

D94A25048

SAT*****

1

High Air Flow Pre-Sat Exchanger

D94A25048-HAF

SL-1,2

2

Switch, Roller Limit (2500)

MCRSW2

SM-1,2

2

Stepper Motor (2500)

PX243G

SMD-1,2

2

Stepper Motor Controller

RD-022

SOL1

1

Valve, Solenoid Air/Gas

A2033

SOL2

1

Valve, Solenoid Refrigeration

A2014S50

SOL3

1

Valve, Solenoid Bleed

A2231

SOL4

1

Valve, Solenoid Sat Fill

A2037

SOL5

1

Valve, Solenoid Pressure Select

B3331

SPKR

1

Minilert Audio-Signal

MINLRT

SSR0-7

8

SSR 5VDC Logic

G4AC5

SSR8-10

3

Solid State Relay

R24D10

SSRB

1

Opto-Rack (8 channel) Board

OP2512

STD-A/D

1

STD Bus A/D Board Assembly

MCM7418

STD-CPU

1

7200 CPU Card Assembly

D93A25036

STD-LCD

1

LCD Card Assembly

D96A00228

STD-MEM

1

BT Memory Card Assembly

D93A25037

STD-PS

1

STD Power Supply Card Assembly

D93A25039

T1 1 Transducer, Flow Meter (2500)

FL824

T2 1 Transducer, Pressure 0-50PSIA

PTE50

T3 1 Transducer, Pressure 0-150PSIA

DTC150A

TB1-1-4

4

Modular Terminal Block, TWIN

PH3001682

TB1-5-7

3

Modular Terminal Block

PH1415089

TB2

10

Terminal Block, 1-Pole

PH3100305

TB3

1

Terminal Barrier Strip -7

TRM7

TIB

1

Terminal Block Interface Module Board

TBD-100

TR1

1

Transformer 230:115V/24VAC 4Amps

F108U

V1 1 Flow Valve Assembly

D91A25058

V2 1 Expansion Valve Assembly

D91A25060_01

V2*****

1

HAF Expansion Valve Assembly

D91A25060-HAF

5-2

Find#

Qty

Description

Part Number

V3 1 Valve, Thermostatic Expansion

NIF-1/2-C

V4 1 Valve, Thermostatic Expansion

NIF-1/8-C

V5 1 Valve, Constant Pressure 5” HG-90#

EV-104

5.2 PNEUMATIC CART

Find# Qty. Description Part Number

ACS**** 1 Enclosure, Air Compressor System ACS2520-115 or -230
AH1 1 Hose, Air, 12.5" D92A25067
AH2 1 Hose, Air, 14.5" D92A25066_01
AH25 1 Hose, Air, 25' D92A25046
AT1 1 Tank, Air Pressure D98A25038_01
BV1 &2 2 Valve, Ball 1/4” FPT 150PSI G5X713
DV 1 Valve, Drain 1/8” NPT B2P4T2
FQC 1 Connector, Female Quick B2-H16
F1 1 Filter, Air F73G2ANQD1
F2 1 Filter, Oil Removal F73C2ANQD0
G1 1 Gauge, 200 PSI 1/4” NPT Pressure G2A148
MQC 1 Connector, Male Quick B2-K16
REG 1 Regulator, Pressure R73G2AKRSN
RV1 1 Valve, 200 PSIG 1/4” MPT Relief G5A710

5.3 AIR BOX ELECTRICAL

Find# Qty. Description Part Number

CBS1 1 Switch, Circuit Breaker 1-Pole 115VAC ACSPWRSW-1
CBS1* 1 Switch, Circuit Breaker 2-Pole 220VAC PWRSW-2P
CF1&2 2 6" Console Fan (120VAC) MR2B3
CF1&2* 2 6" Console Fan (220-240VAC) MR77B3
COMP1&2 2 Compressor, Air DACS2022
HM1 1 Hour Meter, Digital LCD HRMETERACS
HLS 1 Switch, Heat Limit CAP-MR-140-SS
SOL1 1 Valve, Solenoid 110VAC U147121-110
SOL1* 1 Valve, Solenoid 220VAC U147121-220

5.4 OPTION INDICATORS

Asterisk Indicates Optional Parts

* High Voltage (HV) Option Parts
** 50 Hz Option Parts
*** 2500ST Parts
**** Air Compressor System Enclosure (ACS) Option
***** High Flow (HAF) Option

5-3

DWN

RESERVOIR FILL PORT

B

DWF

REV

D

Redrawn in Solid Edge
Changed drawing number from 91M25901

E

REVISIONS

DESCRIPTION

DATE

'08/08/26

APPROVED

'08/12/22

LEFT

RIGHT

D

FRONT

COMPUTER / PRINTER INTERFACE

C

A

BACK

MAIN POWER
SWITCH (CBS1)

AC POWER

1.9" DIAMETER
ACCESS PORT

DIMENSIONS

MODEL A B C D E

2500 R 33.00" 20.00" 20.45" 19.00" 18.00"

838 mm 508 mm 519 mm 514 mm 457 mm

2500 ST 36.00" 23.00" 23.45" 22.00" 21.00"

914 mm 584 mm 595 mm 591 mm 533 mm

PROPRIETARY NOTICE:

2500

USED ONNEXT ASSY

APPLICATION

CHAMBER EXHAUST PORT

AIR SUPPLY INLET (1/4" FTP)

This Drawing and Information Contained Within is Proprietary to Thunder Scientific an d cannot be Copied or Reproduced without Written Permission

TOLERANCES

TOLERANCES

.X
.XX
.XXX

UNLESS OTHERWISE SPECIFIED

TREATMENT

FINISH

± .015
± .010
± .005

+/- 0.50°

NOTE 6

SEE NOTE 7

PRODUCTION

DESIGNATION

25-Z-1

DRAWN

CHECKED

ISSUED

Trissell

THIRD ANGLE PROJECTION

THIRD ANGLE PROJECTION

DATE

'91/06/01

'91/06/01

'91/06/01

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123-3198

Layout, Mechanical / Utility

DWG
SIZE

A

91D25901

1 : 10

REVDWG NO.

SHEETWEIGHTSCALE

D

1 OF 1

EXPANSION VALVE

EXPANSION TEMPERATURE
PROBE (RTD2)

DWN

DWF C

REV

Redrawn in Solid Edge
Changed drawing number from 91A25902

DESCRIPTION DATE

REVISIONS

'09/02/03

APPROVED

'09/02/13

TOP VIEW

FLUID FILL PORT

REAR VIEW

PRESATURATOR
LIQUID LEVEL PROBE

PRESATURATOR
TEMPERATURE PROBE
(RTD1)

CHAMBER TEMPERATURE
PROBE (RTD3)

SATURATION TEMPERATURE
(FLUID JACKET) PROBE (RTD0)

RESERVOIR FILL PORT

LEFT SIDE VIEW

RESERVOIR LEVEL PROBE

PROPRIETARY NOTICE:

PROPRIETARY NOTICE:

PROPRIETARY NOTICE:PROPRIETARY NOTICE:

2500

USED ONNEXT ASSY

APPLICATION

This Drawing and Information Contained Within is Proprietary to Thunder Scientic an d cannot be Copied or Reproduced without Written Permission

TOLERANCES

TOLERANCES

.X
.XX
.XXX

UNLESS OTHERWISE SPECIFIED

TREATMENT

FINISH

± .015
± .010
± .005

+/- 0.50°

NOTE 6

SEE NOTE 7

PRODUCTION
DESIGNATION

25-Z-2

DRAWN

CHECKED

ISSUED

Long

THIRD ANGLE PROJECTION

THIRD ANGLE PROJECTION

DATE

'91/06/01

'91/06/01

'91/06/01

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123-3198

Probe Location Layout

DWG
SIZE

A

1:10

91D25902

SHEETWEIGHTSCALE

REVDWG NO.

C

1 OF 1

DWN

DWF

REV.

D

REVISIONS

DESCRIPTION

Added Card Cage Callout - Drawn to SW

DATE

7/1/2013

APPROVED

T2

LCD-INV
(LCD BACKLIGHT
INVERTER)

TOP VIEW

SOL5

SMD-2

SEE DETAIL "A"

DISPLAY PORT

ANALOG INPUT PORT

TB3

1

2

3

4

5

6

7

ATB
(ANALOG
TERMINAL
BLOCK)

STD-A/D

STD-LCD

CONSOLE PORT

DETAIL "A"

1 : 2

DIGITAL I/O PORT

STD-CPU

STD-MEM

PRINTER PORT

KEYBOARD PORT

WRITE
PROTECT
SWITCH

J1

STD-PS

CARD CAGE
(CC)

NEXT ASSY

APPLICATION

2500

USED ON

PRODUCTION
DESIGNATION

THIRD ANGLE
PROJECTION

25-Z-3

TOLERANCES

.X ±.015
.XX ±.010

.XXX ±.005

UNLESS NOTED OTHERWISE

±.50°

PROPRIETARY NOTICE

THIS DRAWING AND INFORMATION
CONTAINED WITHIN IS PROPRIETARY
TO THUNDER SCIENTIFIC AND
CANNOT BE COPIED OR REPRODUCED
WITHOUT WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

LONG

6/1/1991

6/1/1991

6/1/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Card Cage & Component Layout

DWG. NO.

SIZE

A

SCALE:

N/A

91D25903

N/A

WT.

SHEET 1 OF 1

REV

D

LL2

LL1

TR1

REVISIONS

DWN

DWF

REV.

G

DESCRIPTION

Added FS1 - Drawn to SW

DATE

6/27/2013

APPROVED

TB2

1 2 3 4 5 6 7 8 9

3
2
1

4
3
2
1

FS3

FS2

A0
A1
A2
A3
A4
A5
A6

A7

B0
B1
B2
B3
B4
B5
B6

B7
C0
C1
C2
C3
C4
C5
C6
C7

10

TIB

SSRB

SSR0

SSR1

SSR2

SSR3

SSR4

SSR5

SSR6

SSR7

+

-

1

2
3
4
5
6
7
8
9
10
11
12
13
14

15
16

FS1

PLF1

7
6
5
4
3
2
1

SSR8 SSR9

SSR10

ON BACK

NEXT ASSY

APPLICATION

TB1

2500

USED ON

PRODUCTION
DESIGNATION

THIRD ANGLE
PROJECTION

25-Z-4

TOLERANCES

.X ±.015
.XX ±.010

.XXX ±.005

UNLESS NOTED OTHERWISE

±.50°

PROPRIETARY NOTICE

THIS DRAWING AND INFORMATION
CONTAINED WITHIN IS PROPRIETARY
TO THUNDER SCIENTIFIC AND
CANNOT BE COPIED OR REPRODUCED
WITHOUT WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

LONG

6/1/1991

6/1/1991

6/1/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Electrical Sub Panel Layout

DWG. NO.

SIZE

A

SCALE

N/A

91D25904

N/A

WT.

SHEET 1 OF 1

REV

G

TB1

7

6

5

4

3

2

1

TB2 TB3

FLOW VALVE PULSE (OPEN)

EXP VALVE PULSE (OPEN)

FLOW VALVE PULSE (CLOSE)

PRE-SAT LEVEL PROBE

EXP VALVE LIMIT

FLOW VALVE LIMIT

EXP VALVE PULSE (CLOSE)

COMMON

+ 5 VDC

DWN

REV.

DWF

H

ANLG IN (RES LEVEL)

1 2 3 4 5 6 77654321 8 9 10

+ 12 VDC

COMMON

DESCRIPTION

Drawn to SW

+ 12 VDC

COMMON

REVISIONS

+ 12 VDC

+ 12 VDC

COMMON

DATE

7/25/2014

APPROVED

REFER TO

08S25942

NEXT ASSY

APPLICATION

2500

USED ON

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 6/1/1991

9/23/1993

9/23/1993

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Terminal Layout

DWG. NO.

SIZE

A

SCALE:

1 : 1

91D25905

N/A

WT.

SHEET 1 OF 1

REV

H

L

MOV1

N

MOV1 MOV1

G

POWER

S1

FB1

TB1-1

TB1-2

CHASSIS

PLF1

LOW VOLTAGE

CONFIGURATION

TB1-7

120
VAC

TB1-3

FS3

TR1

1

3

2

4

REVISIONS

DWN

DWF

REV.

F

DESCRIPTION

Drawn to SW

DATE

7/25/2014

APPROVED

TB1-5

24

VAC

FS2

J1-1

J1-4

J1-3
J1-6

J1-7
J1-8

STD-PS

+ 24 VDC (UNREGULATED)
+ 24 RETURN
+ 5 VDC

- 12 VDC
+ 12 VDC

5

7

6

8

J1-5

J1-2

COM

HIGH VOLTAGE

TB1-4

CONFIGURATION

TB1-1TB1-2

TB1-5

TB1-7

FS3

L

S1

240

VAC

TB1-3

MOV1

N

POWER

MOV1MOV1

CHASSIS

G

FB1

NEXT ASSY

USED ON

APPLICATION

PLF1

2500

THIRD ANGLE
PROJECTION

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

TR1

1

3

2

4

5

7

VAC

6

8

FS2

24

TB1-4

PROPRIETARY NOTICE

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

±.50°

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 6/1/1991

6/1/1991

6/1/1991

STD-PS

J1-1

J1-4

J1-3
J1-6

J1-7
J1-8

+ 24 VDC (UNREGULATED)
+ 24 RETURN
+ 5 VDC

- 12 VDC
+ 12 VDC

J1-5

J1-2

COM

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

AC / DC Power Schematic

DWG. NO.

SIZE

A

SCALE:

1 : 1

91S25906

WT.

N/A

SHEET 1 OF 1

REV

F

TB2-9

LOGIC +

SSRB

REVISIONS

DWN

REV.

DWF

D

1

TB1-6

DWF

E

All Relays AC - Revised Terminal Notations

DESCRIPTION

Drawn to SW

DATE

7/25/2014

1/4/2016

APPROVED

STD-CPU

I/O PORT

(-)

SSR0

2

3

(-)

SSR1

4

HLS3

SOL2

REFRIGERANT

SOLENOID

H4 & H5

EXPANSION

VALVE HEATER

5

(-)

SSR2

6

7

SOL4

PRE SATURATOR

FILL SOLENOID

(-)

SSR3

8

9

SOL3

PRESSURE BLEED

SOLENOID

(-)

SSR4

10

11

(-)

SSR5

12

13

TB1-4

TB1-1

SOL5

PRESSURE SELECT

SOLENOID

SOL1

AIR / GAS SUPPLY

SOLENOID

(-)

SSR6

14

FP1

FLUID PUMP

15

(-)

SSR7

NEXT ASSY

APPLICATION

16

2500

USED ON

TB1-2

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

CF1

CONSOLE FAN

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 5/31/1991

5/31/1991

5/31/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Solid State Relay Module Board

DWG. NO.

SIZE

A

SCALE:

1 : 1

91S25907

N/A

WT.

SHEET 1 OF 1

REV

E

DWN

DWF

REV.

D

REVISIONS

DESCRIPTION

Drawn to SW

DATE

7/28/2014

APPROVED

TIB

B5

B6

B4

TB1-1 TB2-9

SSR10-2

3 4

HLS2

TB1-2

3 4

1 2

SSR9

H3

R MODEL 110 V

3 4

1 2

SSR10

SSR10-2

HLS2

HLS1

HLS2

H3

H1 H2

(HV OPTION)

H1

H2

TB1-2

H3

NC

R MODEL 220 V

TB1-2

FLUID HEATER

(ST CONFIGURATION)

PRE SATURATOR

HEATERS

1 2

SSR8

NEXT ASSY

APPLICATION

2500

USED ON

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 6/1/1991

6/1/1991

6/1/1991

REFRIGERATION

C1

COMPRESSOR

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Compressor / Heater Schematic

DWG. NO.

SIZE

A

SCALE:

1 : 1

91S25908

N/A

WT.

SHEET 1 OF 1

REV

D

DWN

DWF

REV.

F

REVISIONS

DESCRIPTION

Drawn to SW

DATE

7/28/2014

APPROVED

A2

TIB

TB2-8 TB2-9

TB2-10

LL1

1

2

3

4

LL2

1

2

3

ANLG

NC

PWR

COM

ALM

PWR

COM

RESERVOIR

LEVEL PROBE

PRE SATURATOR

LEVEL PROBE

TB2-1

B7

NEXT ASSY

APPLICATION

2500

USED ON

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

SPKR

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 6/1/1991

6/1/1991

6/1/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Liquid Level / Speaker Schematic

DWG. NO.

SIZE

A

SCALE:

1 : 1

91S25909

N/A

WT.

SHEET 1 OF 1

REV

F

DWN

DWF

DWF

REV.

D

E

REVISIONS

DESCRIPTION

Drawn to SW

Revised Terminal Notations

DATE

7/28/2014

1/4/2016

APPROVED

TIB

A1

B1

B3

TB2-6

TB2-3

TB2-2

(24 VDC RETURN)

SL-1

(N.C.)

J1-3

CLOSE PULSE

OPEN PULSE

TB2-9

(+5 VDC)

J1-4

(+24 VDC UNREG)

Vcc

GND

CW+

CCW+

CW-

CCW-

SMD-1

C1

C2

A

A

B

BLK

YEL

GRN

RED

SM-1

STEPPER

MOTOR

WHT

B

BLU

NEXT ASSY

APPLICATION

2500

USED ON

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

STEPPER

MOTOR
DRIVER

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 5/31/1991

5/31/1991

5/31/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Flow Valve (V1) Control Schematic

DWG. NO.

SIZE

A

SCALE:

1 : 1

91S25910

N/A

WT.

SHEET 1 OF 1

REV

E

DWN

DWF

DWF

REV.

C

D

REVISIONS

DESCRIPTION

Drawn to SW

Revised Terminal Notations

DATE

7/28/2014

1/4/2016

APPROVED

TIB

A0

B0

B2

TB2-7

TB2-5

TB2-4

(24 VDC RETURN)

SL-2

(N.C.)

J1-3

CLOSE PULSE

OPEN PULSE

TB2-9

(+5 VDC)

J1-4

(+24 VDC UNREG)

Vcc

GND

CW+

CCW+

CW-

CCW-

SMD-2

C1

C2

A

A

B

BLK

YEL

GRN

RED

SM-2

STEPPER

MOTOR

WHT

B

BLU

NEXT ASSY

APPLICATION

2500

USED ON

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

STEPPER

MOTOR
DRIVER

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 5/31/1991

5/31/1991

5/31/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Exp. Valve (V2) Control Schematic

DWG. NO.

SIZE

A

SCALE:

1 : 1

91S25911

N/A

WT.

SHEET 1 OF 1

REV

D

CH 5

CH 6

CH 7

CH 0

CH 1

CH 2

CH 3

CH 4

V+ 8

V- 9

V+ 13

V- 14

V+ 18

V- 19

V+

I+
S
I-

V-

V+
I+
S
I­V-

V+

I+

S

I­V-

V+
I+

S
I-

V-

V+
I+
I­V-

REVISIONS

TB3

6 7 4 5 2 1

DWF

REV.

D

DESCRIPTION

Drawn to SW

DATE

7/28/2014

APPROVED

DWN

P2

A

B
D

T2

0-50 PSIA

LOW RANGE

C

P3

A
B
D

T3

0-150 PSIA

HIGH RANGE

C

P1

4

7
3

T1

0-20 SLPM

FLOW

2

3
1

5
2
4

8
6

10

7
9

13
11

15
12
14

18
16

20
17

19

3
1
2
4

10K Ω

REFERENCE

10K Ω

10K Ω

10K Ω

10K Ω

NEXT ASSY

APPLICATION

t°

RTD0

SATURATION

TEMPERATURE

t°

RTD1

PRE SATURATOR

t°

RTD2

EXPANSION VALVE

t°

RTD3

CHAMBER

THIRD ANGLE
PROJECTION

2500

USED ON

TOLERANCES

UNLESS NOTED OTHERWISE

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

.XXX ±.010

±.50°

PROPRIETARY NOTICE

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 6/1/1991

6/1/1991

6/1/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Temp Probe / Transducer Schematic

DWG. NO.

SIZE

A

SCALE:

1 : 1

91S25912

N/A

WT.

SHEET 1 OF 1

REV

D

STD BUS

DWN

DWF

REV.

C

REVISIONS

DESCRIPTION

Drawn to SW

DATE

7/28/2014

APPROVED

STD-PS

POWER SUPPLY BOARD

LCD-INV

INVERTER BOARD

LCD

LIQUID CRYSTAL

DISPLAY

STD-LCD

DISPLAY DRIVER BOARD

SSRB

SOLID STATE

RELAY BOARD

TIB

TERMINAL INTERFACE

BOARD

STD-CPU

STD-A/D

ANALOG BOARD

ATB

ANALOG TERMINAL

BOARD

KB

KEYBOARD

CONSOLE

PORT

PRINTER

PORT

STD-MEM

MEMORY BOARD

NEXT ASSY

APPLICATION

2500

USED ON

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 6/1/1991

6/1/1991

6/1/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

STD Bus Diagram

DWG. NO.

SIZE

A

SCALE:

1 : 1

91D25913

N/A

WT.

SHEET 1 OF 1

REV

C

STD BUS

STD-LCD

DRIVER BOARD

1 1

REVISIONS

DWN

DWF

REV.

C

DESCRIPTION

Drawn to SW

DATE

7/28/2014

APPROVED

LCD

LIQUID CRYSTAL DISPLAY

1414

(HIGH VOLTAGE)

BACKLIGHT

DRIVE

J1-5 (COMMON)

J1-7 (-12 VDC)

NEXT ASSY

USED ON

APPLICATION

2500

+

LCD BACKLIGHT

-

UNLESS NOTED OTHERWISE

LCD-INV

INVERTER

THIRD ANGLE
PROJECTION

TOLERANCES

.XXX ±.010

±.50°

PROPRIETARY NOTICE

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 6/1/1991

6/1/1991

6/1/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Display Block Diagram

DWG. NO.

SIZE

A

SCALE:

1 : 1

91S25914

N/A

WT.

SHEET 1 OF 1

REV

C

DWN

REV.

DWF

C

CONNECTOR PINOUT

REVISIONS

DESCRIPTION

Drawn to SW

DATE

7/28/2014

APPROVED

RS-232C

CONSOLE

PORT

PRINTER

PORT

PIN #

1
2
3

5

9

4

8

3

7

2

6

1

4
5
6
7
8
9

CONSOLE

PORT

NC

TxD

RxD

DSR**

SIG GND

DTR**

RTS

CTS*

NC

PRINTER

PORT

NC

TxD

RxD

DSR**

SIG GND

DTR**

RTS

CTS*

NC

* = TIED TO +5V VIA 4.7K RESISTOR

** = BENCHTOP DOES NOT SUPPORT
DSR & DTR SIGNALS. PINS 4 & 6
ARE STRAPPED TOGETHER WITHIN
BENCHTOP FOR THE USE OF
PERIPHERAL EQUIPMENT.

1

6

2

7

3

8

4

9

5

TO CONNECT A SERIAL PRINTER TO THE PRINTER PORT,
USE PRINTER CABLE (PART #: PCABLE) OR A STANDARD
MODEM CABLE

PRINTER CONNECTION

COMPUTER CONNECTION

TO CONNECT ANY IBM COMPATABLE COMPUTER TO THE CONSOLE
PORT, USE CONSOLE CABLE (PART #: CCABLE) OR 9 PIN
EXTENDER CABLE. CONNECTION TO ANY OLDER COMPUTER MAY
REQUIRE AN ADAPTER CABLE OR CONNECTOR. (NOT PROVIDED)

THESE CONNECTIONS CAN BE
FOUND ON THE LOWER RIGHT

HAND CORNER OF THE

LEFT SIDE PANEL

NEXT ASSY

APPLICATION

2500

USED ON

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

MODEM CONNECTION

TO CONNECT A MODEM TO THE CONSOLE PORT, USE MODEM
CABLE (PART #: MCABLE)

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 6/1/1991

6/1/1991

6/1/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

RS-232C / Printer Console

DWG. NO.

SIZE

A

SCALE:

1 : 1

91D25915

N/A

WT.

REV

C

SHEET 1 OF 1

DWN

DWF

REV.

C

REVISIONS

DESCRIPTION

Changed CV1 to PT1 Drawn to SW

DATE

6/27/2013

APPROVED

AIR / GAS
SUPPLY

(RV1)

(SOL1)

(REG)

(G1)

(T1)

(V1)

DISTILLED
WATER IN

(RTD3)

(RES)

PRESSURE BLEED

(SOL3)

NORMALLY OPEN

PSAT

SAT

TEST

CHAMBER

(RTD2)

(V2)

(T2)

(SOL5)

EXHAUST

(T3)

NEXT ASSY

APPLICATION

2500

USED ON

(SOL4)

(PT1)

PRODUCTION
DESIGNATION

THIRD ANGLE
PROJECTION

25-Z-16

TOLERANCES

.X ±.015
.XX ±.010

.XXX ±.005

UNLESS NOTED OTHERWISE

±.50°

(RTD1)

PROPRIETARY NOTICE

THIS DRAWING AND INFORMATION
CONTAINED WITHIN IS PROPRIETARY
TO THUNDER SCIENTIFIC AND
CANNOT BE COPIED OR REPRODUCED
WITHOUT WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

LONG

6/1/1991

6/1/1991

6/1/1991

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Pneumatic System Schematic

DWG. NO.

SIZE

A

SCALE

N/A

91S25916

N/A

WT.

SHEET 1 OF 1

REV

C

TEST

CHAMBER

FLUID FILL

PORT

DWN

DWF

DWF

REV.

D

E

REVISIONS

DESCRIPTION

Drawn to SW

Updated Component Notations

OUT

DATE

7/29/2014

1/5/2016

APPROVED

SATURATOR

SAT

NEXT ASSY

APPLICATION

PUMP

FP1

2500

USED ON

RTD0

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 5/31/1991

5/31/1991

5/31/1991

EX1

REFRIGERANT

IN

H3

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Heat Transfer Fluid Schematic

DWG. NO.

SIZE

A

SCALE:

1 : 1

91S25917

N/A

WT.

SHEET 1 OF 1

REV

E

(V5)

(V4)

DWN

DWF

REV.

C

DESCRIPTION

Drawn to SW

(V3)

REVISIONS

CHAMBER

IN

(EX1)

DATE

7/29/2014

APPROVED

(C1)

NEXT ASSY

APPLICATION

2500

USED ON

(CON)

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

(FD)

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Long 6/1/1991

6/1/1991

6/1/1991

OUT

(SOL2)

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Refrigeration System Schematic

DWG. NO.

SIZE

A

SCALE:

1 : 1

91S25918

N/A

WT.

SHEET 1 OF 1

REV

C

DWN

DWF

DWF

REV.

D

E

REVISIONS

DESCRIPTION

Updated to Current Configuration

Updated with new ACS

DATE

4/29/2013

6/20/2014

APPROVED

G1

AT1

BV1

A

FRONT

AH2

BV2

C

B

REG

AH1

F2
F1

RIGHT SIDE

DV

D

MODEL

2500

2500 ST

BACK

DIMENSIONS

A B

40.00" 23.00" 24.00" 33.25"

1.02M

584mm 609mm 845mm

43.00" 26.00" 24.00" 33.25"

1.09M

660mm 609mm 845mm

C D

NEXT ASSY

APPLICATION

2500

USED ON

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

SMITH

LEFT SIDE

11/12/1998

11/12/1998

11/12/1998

ACS

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

ACS with Cart Layout

DWG. NO.

SIZE

A

SCALE:

1 : 16

98D25919

WT.

287.27

SHEET 1 OF 1

REV

E

G1

DWN

DWF

DWF

REV.

E

F

REVISIONS

DESCRIPTION

Removed Muffler - Drawn to SW

Replaced RV1 & COMP1 with ACS

Changed RV2 to RV1

DATE

4/15/2013

7/10/2014

APPROVED

ACS

FQC

AH25

MQC

BV2

NEXT ASSY

APPLICATION

AT1

DV

2500

USED ON

BV1

RV1

PRODUCTION
DESIGNATION

THIRD ANGLE
PROJECTION

25-Z-21

TOLERANCES

.X ±.015
.XX ±.010

.XXX ±.005

UNLESS NOTED OTHERWISE

±.50°

AH1

LONG

2

FF

6/1/1991

6/1/1991

6/1/1991

1

PROPRIETARY NOTICE

THIS DRAWING AND INFORMATION
CONTAINED WITHIN IS PROPRIETARY
TO THUNDER SCIENTIFIC AND
CANNOT BE COPIED OR REPRODUCED
WITHOUT WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

AH2

GENERATOR

REG

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Cart Pneumatic System Schematic

DWG. NO.

SIZE

A

SCALE

N/A

91S25921

WT.

N/A

SHEET 1 OF 1

REV

F

FRONT

DWN

DWF

REV.

D

REVISIONS

DESCRIPTION

Added funnel assembly - Drawn to SW

DATE

7/12/2013

APPROVED

REMOVE THIS PANEL

Chamber Fluid Filling Requires:

T10 Torx Driver
Funnel
3 U.S. gallons of propylene glycol
(4 U.S. gallons for 2500ST - supplied)

CHAMBER FLUID FILLING INSTRUCTIONS

Remove top right console panel (panel above chamber)

1.
Locate fluid fill port (under insulation and labeled "Fluid Fill Port").

2.
Remove red cap and insert funnel into fluid fill port.

3.
Using 3 U.S. gallons of -100° C propylene glycol mix

4.
(4 U.S. gallons for 2500ST) fill until level is approximately
1/4" below bottom of fill port, or to bottom of funnel.
Remove funnel and replace fluid fill port cap and insulation.

5.
Replace top right console panel.

6.
Chamber fluid filling is now complete.

7.

NEXT ASSY

APPLICATION

2500ST

2500

USED ON

TOP

FILL PORT

PRODUCTION
DESIGNATION

THIRD ANGLE
PROJECTION

25-Z-24

TOLERANCES

.X ±.015

.XX ±.010

.XXX ±.005

UNLESS NOTED OTHERWISE

±.50°

REAR VIEW

PROPRIETARY NOTICE

THIS DRAWING AND INFORMATION
CONTAINED WITHIN IS PROPRIETARY
TO THUNDER SCIENTIFIC AND
CANNOT BE COPIED OR REPRODUCED
WITHOUT WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

FISCHER

3/13/1997

3/13/1997

3/13/1997

NO PROPYLENE
GLYCOL IN THIS PORT

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Chamber Fluid Filling Instructions

DWG. NO.

SIZE

A

SCALE:

N/A

97D25924

WT.

203.05

SHEET 1 OF 1

REV

D

TOP VIEW

DWN

DWF

REV.

E

REVISIONS

DESCRIPTION

Drawn to SW - Added ST Cart Dimensions

DATE

7/29/2014

APPROVED

MODEL

2500

2500 ST

DIMENSIONS
A B C D

40.00" 23.00" 24.00" 33.25"

1.02M

584mm 609mm 845mm

43.00" 26.00" 24.00" 33.25"

1.09M

660mm 609mm 845mm

A

FRONT VIEW

NEXT ASSY

APPLICATION

2500

USED ON

C

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Fischer

4/14/1997

4/14/1997

4/14/1997

B

D

SIDE VIEW

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

Cart Mechanical Dimensions

SIZE

A

SCALE:

DWG. NO.

1 : 15

WT.

97D25926

163.04

SHEET 1 OF 1

REV

E

FOR 110V FS3 = 3.15A
FOR 240V FS3 = 1.6A

TB1

DWN

DWF

REV.

C

REVISIONS

DESCRIPTION

Drawn to SW

DATE

7/29/2014

APPROVED

TRANSFORMER

PRIMARY LINE IN

TRANSFORMER

SECONDARY LINE IN

24 VAC

TRANSFORMER

SECONDARY NEUTRAL

24 VAC

TRANSFORMER

PRIMARY

NEUTRAL

NEUTRAL IN

LINE IN

RED

RED

WHITE

WHITE

WHITE

RED

18
GA

16
GA

16 GA

18 GA

14 GA

14 GA

4A

FS3

18
GA

BROWN

RFI FILTER LINE OUT

7

16

6

FS2

GA

16
GA

5

18 GA

4

16 GA

16 GA

RED

RED

WHITE

WHITE

BLUE

24 VAC TO SSRB

24 VAC TO POWER
SUPPLY CARD

24 VAC NEUTRAL

24 VAC NEUTRAL TO
POWER SUPPLY CARD

RFI FILTER NEUTRAL OUT

3

14 GA

2

18 GA

14 GA

1

18 GA

WHITE

BLUE

RED

BROWN

NEUTRAL COMMON

RFI FILTER NEUTRAL IN

RELAY LINE IN

RFI FILTER LINE IN

NEXT ASSY

APPLICATION

2500

USED ON

THIRD ANGLE
PROJECTION

THIS DRAWING AND INFORMATION CONTAINED

WITHIN IS PROPRIETARY TO THUNDER SCIENTIFIC

AND CANNOT BE COPIED OR REPRODUCED WITHOUT

TOLERANCES

.XXX ±.010

UNLESS NOTED OTHERWISE

±.50°

PROPRIETARY NOTICE

SPECIFIC WRITTEN PERMISSION

DRAWN

CHECKED

ISSUED

Furry

10/3/2008

12/28/2008

12/30/2008

Thunder Scientific Corporation

623 Wyoming S.E. Albuquerque, NM 87123

2500 Fuse Upgrade Schematic

DWG. NO.

SIZE

A

SCALE:

1 : 1

08S25942

N/A

WT.

SHEET 1 OF 1

REV

C