Kaye CTR-40 User guide

Kaye CTR-40

Cold Temperature Reference
User’s Guide

M4436 Rev. B, 12/19

Kaye CTR-40

Cold Temperature
Reference

User's Guide

M4436 Rev. B, 12/19

Amphenol

Advanced Sensors

www.amphenol-sensors.com

©2019 Amphenol Thermometrics, Inc. All rights reserved.
Technical content subject to change without notice.

LIMITED WARRANTY AND LIMITATION OF LIABILITY

Each KAYE product is warranted to be free from defects in material and workmanship under normal use and
service. The warranty period is one year and begins on the date of shipment. Parts, product repairs, and
services are warranted for 90 days. This warranty extends only to the original buyer or end-user customer of
a KAYE authorized reseller, and does not apply to fuses, disposable batteries, or to any product which, in
KAYE’S opinion, has been misused, altered, neglected, contaminated, or damaged by accident or abnormal
conditions of operation or handling. KAYE warrants that software will operate substantially in accordance
with its functional specifications for 90 days and that it has been properly recorded on non-defective media.
KAYE does not warrant that software will be error free or operate without interruption.

KAYE authorized resellers shall extend this warranty on new and unused products to end-user customers
only but have no authority to extend a greater or different warranty on behalf of KAYE. Warranty support is
available only if product is purchased through a KAYE authorized sales outlet or Buyer has paid the
applicable international price. KAYE reserves the right to invoice Buyer for importation costs of
repair/replacement parts when product purchased in one country is submitted for repair in another country.

KAYE warranty obligation is limited, at KAYE's option, to refund of the purchase price, free of charge repair,
or replacement of a defective product which is returned to a KAYE authorized service center within the
warranty period.

To obtain warranty service, contact your nearest KAYE authorized service center to obtain return
authorization information, then send the product to that service center, with a description of the difficulty,
postage and insurance prepaid (FOB Destination). KAYE assumes no risk for damage in transit. Following
warranty repair, the product will be returned to Buyer, transportation prepaid (FOB Destination). If KAYE
determines that failure was caused by neglect, misuse, contamination, alteration, accident, or abnormal
condition of operation or handling, including overvoltage failures caused by use outside the product’s
specified rating, or normal wear and tear of mechanical components, KAYE will provide an estimate of repair
costs and obtain authorization before commencing the work. Following repair, the product will be returned to
the Buyer transportation prepaid and the Buyer will be billed for the repair and return transportation charges
(FOB Shipping Point).

THIS WARRANTY IS BUYER'S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. KAYE SHALL NOT BE LIABLE
FOR ANY SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES OR LOSSES,
INCLUDING LOSS OF DATA, ARISING FROM ANY CAUSE OR THEORY.

Since some countries or states do not all

ow limitation of the term of an implied warranty, or exclusion or
limitation of incidental or consequential damages, the limitations and exclusions of this warranty may not
apply to every buyer. If any provision of this Warranty is held invalid or unenforceable by a court or other
decision-maker of competent jurisdiction, such holding will not affect the validity or enforceability of any other
provision.

Asia, and Middle East
Amphenol Advanced Sensors Germany GmbH
Sinsheimer Strasse 6
D-75179 Pforzheim
T [phone]
F [phone]

[e-mail]
www.kayeinstruments.com

India:

Amphenol Interconnect India Pvt Ltd.
Plot no. 6, Survey No.64
Software Units layout
MAHAVEER TECHNO PARK
Hitech City, Madhapur
Hyderabad, Telangana – 500081
T: [phone]

U.S.A., and Europe
Kaye Thermometrics, Inc.
967 Windfall Road
St. Marys, PA 15857
Tel: [phone]
Fax: +[phone]

[e-mail]
www.kayeinstruments.com

China:
Sales and Service
Amphenol (Changzhou) Connector Systems
305 Room 5D
Jintong Industrial Park
Wujin, Changzhou, Jiangsu, China
T: [phone] x 50087
F: [phone]

Table of Contents

1

Before You Start ................................................................................................. 1

1.1 Symbols Used .................................................................................................................................... 1

1.2 Safety Information ............................................................................................................................ 2

1.2.1 Warning s ....................................................................................................................................................................................... 2

1.2.2 Cautions .......................................................................................................................................................................... 4

2

Introduction ........................................................................................................ 7

3

Specifications and Environmental Conditions ................................................ 9

3.1 Specifications ................................................................................................................................... 9

3.2 Environmental Conditions ............................................................................................................. 10

3.3 Hardware Warranty and Assistance ...................................................................................................... 10

3.3.1 Instrument Warranty ................................................................................................................................................................ 10

3.3.2 In-Warranty Repairs .................................................................................................................................................................. 10

3.3.3 After-Warranty Repairs ............................................................................................................................................................ 11

3.3.4 Equipment Maintenance Agreements .................................................................................................................... 11

3.3.5 Customer Support ........................................................................................................................................................ 11

3.3.6 Customer Support Agreement .................................................................................................................................. 12

3.3.7 Customer Site Assistance ............................................................................................................................................ 12

4

Quick Start ........................................................................................................ 13

4.1 Unpacking....................................................................................................................................... 13

4.2 Set Up ............................................................................................................................................... 13

4.3 Power ............................................................................................................................................................. 1 4

4.4 Setting the Temperature........................................................................................................................... 14

5

Installation ................................................................................................ 17

5.1 Bath Environment ........................................................................................................................... 17

5.2 “Dry-out” Period ......................................................................................................................................... 17

5.3 Bath Preparation and Filling .......................................................................................................... 17

5.3.1 Drain Valve Installation Instructions ........................................................................................................................... 17

5.3.2 Filling With Fluid .................................................................................................................................... 18

5.4 Power ............................................................................................................................................................. 1 9

6

Parts and Controls ........................................................................................... 21

6.1 Front Panel ......................................................................................................................................... 21

6.2 Bath Tank and Lid. ......................................................................................................................... 22

6.3 Back Panel .................................................................................................................................................. 22

ii

7

General Operation........................................................................................... 23

7.1

Heat Transfer Fluid ....................................................................................................23

7.1.1 Temperature Range ......................................................................................................................................................... 23

7.1.2 Viscosity.................................................................................................................................................................. 23

7.1.3 Specific Heat................................................................................................................................................................. 24

7.1.4 Thermal Conductivity ................................................................................................................................................... 24

7.1.5 Thermal Expansion ................................................................................................................................................ 24

7.1.6 Electrical Resistivity ........................................................................................................................................................... 25

7.1.7 Fluid Lifetime ......................................................................................................................................... 25

7.1.8 Safety ..................................................................................................................................................................... 25

7.1.9 Cost 26

7.1.10 Commonly Used Fluids ......................................................................................................................................... 26

7.1.11 Fluid Characteristics Charts................................................................................................................................. 27

7.1.10.1 Water .............................................................................................................................................................. 26

7.1.10.2 Ethylene Glycol ........................................................................................................................... 26

7.1.10.3 Mineral Oil ..................................................................................................................... 27

7.1.10.4 Silicone Oil ..................................................................................................................... 27

7.1.11.1 Limitations and Disclaimer ......................................................................................................... 27

7.1.11.2 About the Graph ............................................................................................................................... 28

7.2 Stirring ........................................................................................................................30

7.3 Power ............................................................................................................................................. 30

7.4 Heater ............................................................................................................................... 31

7.5 Temperature Controller ................................................................................................... 31

7.6 Refriger ation ............................................................................................................................. 32

8

Controller Operation ............................................................................. 35

8.1 Bath Temperature ...................................................................................................................... 35

8.2 Reset Cutout .............................................................................................................................. 35

8.3 Temperature Set-point .................................................................................................... 37

8.3.1 Programmable Set-points ......................................................................................................................... 37

8.3.2 Set-point Value ............................................................................................................................................................ 38

8.3.3 Set-point Vernier ................................................................................................................................................... 38

8.4 Scan .................................................................................................................................. 39

8.4.1 Scan Control .............................................................................................................................................. 39

8.4.2 Scan Rate ....................................................................................................................................................................... 39

8.5 Temperature Scale Units ................................................................................................. 40

8.6 Ramp and Soak Program ...................................................................................................... 40

8.6.1 Number of Program Set-points ................................................................................................................ 40

8.6.2 Set-points .................................................................................................................................................... 41

8.6.3 Program Soak Time .................................................................................................................................... 41

8.6.4 Program Function Mode ........................................................................................................................... 42

8.6.5 Program Control ........................................................................................................................................ 42

iii

8.7 Secondary Menu ...................................................................................................................... 43

8.8 Heater Power ............................................................................................................................... 4 3

8.9 Proportional Band ............................................................................................................ 43

8.10 Cutout ........................................................................................................................................ 46

8.11 Controller Configuration ................................................................................................. 47

8.12 Probe Parameters ................................................................................................................... 47

8.12.1 R0 ............................................................................................................................................... 47

8.12.2 ALPHA ........................................................................................................................................ 48

8.13 Operating Parameters .......................................................................................................... 48

8.13.1 Cutout Reset Mode ........................................................................................................................................... 48

8.13.2 Cooling Mode ................................................................................................................................................... 48

8.13.3 Hot Gas Bypass Mode .............................................................................................................................. 49

8.14 Serial Interface Parameters ...................................................................................................... 5 0

8.14.1 Baud Rate ............................................................................................................................................................... 5 0

8.14.2 Sample Period ....................................................................................................................................................... 50

8.14.3 Duplex Mode ............................................................................................................................................. 51

8.14.4 Linefeed ..................................................................................................................................................... 51

8.15 Calibration Parameters ......................................................................................................... 52

8.15.1 CTO .......................................................................................................................................................................... 52

8.15.2 CO and CG ....................................................................................................................................................... 52

8.15.3 H and L ........................................................................................................................................ 52

8.15.4 HGbt............................................................................................................................................................ 53

9

Digital Communication Interface ........................................................ 55

9.1 Serial Communications ................................................................................................... 55

9.1.1 Wiring .......................................................................................................................................... 56

9.1.2 Setup ........................................................................................................................................................... 56

9.1.2.1 Baud Rate ............................................................................................................................................... 5 6

9.1.2.2 Sample Period ....................................................................................................................................... 57

9.1.2.3 Duplex Mode .............................................................................................................................. 57

9.1.2.4 Linefeed ....................................................................................................................................... 57

9.1.3 Serial Operation ........................................................................................................................................ 57

9.2 Interface Commands .............................................................................................................. 57

9.3 Cooling Control ............................................................................................................... 58

10

Calibration Procedure .............................................................................. 63

10.1 Calibration Points ........................................................................................................................ 63

10.2 Measuring the Set-point Error ......................................................................................... 63

10.3 Computing R0 and ALPHA ............................................................................................. 63

10.4 Calibration Example ....................................................................................................... 65

iv

11

Maintenance .......................................................................................... 66

12

Troubleshooting ... ....................................................................................... 68

12.1 Troubleshooting .. ......................................................................................................................... 68

12.2 Comments .... .................................................................................................................... 71

12.2.1 EMC Directive . ........................................................................................................................................... 71

12.2.2 Low Voltage Directive (Safety) ................................................................................................................ 71

12.3 Wiring Diagram . ............................................................................................................... 72

iii

Figures

Figure 1 Drain Valve Installation —IMPORTANT: Do Not Over Tighten. ....................................................

Figure 2

Figure 3 Front Panel ...................................................................................................................................................

Figu re 4 C hart o f Various Bath Fluid s and T heir P roperties .............................................................................. 29

Figure 5
Figure 6
Figure 7
Figure 8
Figure 9

Tank Baffle Showing Minimum and Maximum Fill Levels ..................................................................

Controller Operation Flowchart .........................................................................................................................

Bath Temperature Fluctuation At Various Proportional Band Settings .............................................

Serial Communications Cable Wiring ................................................................................................... 56

Calibration Example .............................................................................................................................................. 64

Wiring Diagram ...................................................................................................................................... 75

18
19
21

36
44

vi

Tables

Table 1
Table 2
Table 3
Table 4
Table 5
Table 5
Table 5

International Electrical Symbols ......................................................................................... 1

Table of Various Bath Fluids and Their Properties ................................................................. 28

Program Mode Setting Actions ......................................................................................... 42

Typical Proportional Band Settings for Various Fluids ....................................................... 45

Interface Command Summary ........................................................................................ 59

Interface Command Summary Continued .................................................................... 60

Interface Command Summary Continued .................................................................... 61

v

1 Before You Start

1

Before You Start

1.1

Symbols Used

Table 1 lists the International Electrical Symbols. Some or all of these symbols
may be used on the instrument or in this manual.

Table 1

International Electrical Symbols

Symbol

Description

AC (Alternating Curre nt)

AC-DC

Battery

Complies with European Union directives

DC

Double Insulated

Electric Shock

Fuse

PE Ground

Hot Surface (Burn Hazard)

Read the User’s Manual (Important Information)

Off

On

1

1 Before You Start

1.2

1.2.1

Symbol

Safety Information

Use this instrument only as specified in this manual. Otherwise, the protection
provided by the instrument may be impaired. Refer to the safety information
below.

The following definitions apply to the terms “Warning” and “Caution”.

• “Warning” identifies conditions and actions that may pose hazards to the

user.

• “Caution” identifies conditions and actions that may damage the

instrument being used.

Warnings

Description

Canadian St

andards Association

To avoid personal injury, follow these guidelines.

GENERAL

• DO NOT use the instrument for any application other than calibration

work. The instrument was designed for temperature calibration. Any other
use of the unit may cause unknown hazards to the user.

• DO NOT use the unit in environments other than those listed in the user’s

guide.

• DO NOT overfill the bath. Overflowing extremely cold or hot fluid may

be harmful to the operator. See Section 5.3, Bath Preparation and Filling,
for specific instructions.

• Follow all safety guidelines listed in the user’s manual.

• Calibration Equipment should only be used by Trained Personnel.

2

1 Before You Start

• If this equipment is used in a manner not specified by the manufacturer,

the protection provided by the equipment may be impaired.

• Before initial use, or after transport, or after storage in humid or semi-hu-

mid environments, or anytime the instrument has not been en

ergized for
more than 10 days, the instrument needs to be energized for a "dry-out"
period of 2 hours before it can be assumed to meet all of the safety re­quirements of the IEC 1010-1. If the product is wet or has been in a wet
environment, take necessary measures to remove moisture prior to apply­ing power such as storage in a low humidity temperature chamber operat­ing at 50 degree centigrade for 4 hours or more.

• DO NOT operate high temperature baths (500°C) near flammable materi-

als. Extreme temperatures could ignite the flammable material.

• Overhead clearance is required. Do not place the instrument under a cabi-

net or other structure. Always leave enough clearance to allow for safe
and easy insertion and removal of probes.

• The instrument is intended for indoor use only.

BURN HAZARD

• Extremely cold temperatures may be present in this equipment. Freeze

burns and frostbite may result if personnel fail to observe safety precau­tions.

• High temperatures may be present in this equipment. Fires and severe

burns may result if personnel fail to observe safety precautions.

ELECTRICAL HAZARD

• These guidelines must be followed to ensure that the safety mechanisms

in this instrument will operate properly. This instrument must be plugge
into a 115 VAC, 60Hz (230 VAC, 50Hz optional), AC only electric outlet.
The power cord of the instrument is equipped with a three-pronged
grounding plug for your protection against electrical shock

hazards. It
must be plugged directly into a properly grounded three-prong receptacle.
The receptacle must be installed in accordance with local codes and ordi­nances. Consult a qualified electrician. DO NOT use an extension cord or
adapter plug.

• DO use a ground fault interrupt device. This unit contains a liquid. A

ground fault device is advised in case liquid is present in the

electrical

system and could cause an electrical shock.

• Always replace the power cord with an approved cord of the correct rat-

ing and type. If you have questions, contact Amphenol Advanced
Sensors Customer Service.

r

d

3

1 Before You Start

1.2.2

• High voltage is used in the operation of this equipment. Severe injury or

death may result if personnel fail to observe the safety precautions. Before
working inside the equipment, turn off the power and disconnect th
power cord.

BATH FLUIDS

• Fluids used in this unit may produce noxious or toxic fumes under certain

circumstances. Consult the fluid manufacturer’s MSDS (Material Safety
Data Sheet). Proper ventilation and safety precautions must be observed.

• The instrument is equipped with a soft cutout (user settable firmware) and

a hard cutout (set at the factory). Check the flash point, boiling point, or
other fluid characteristic applicable to the circumstances of the unit opera­tion. Ensure that the soft cutout is adjusted to the fluid characteristics of
the application. As a guideline, the soft cutout should be set 10°C to 15°C
below the flash point of the bath fluid. See Section 7.1, Heat Transfer
Fluid, for specific information on bath fluids and Section 8.10, Cutout.

e

Cautions

• THE DRAIN VALVE MUST BE INSTALLED ON THE BACK OF THE

BATH BEFORE ATTEMPTING TO FILL THE TANK WITH FLUID.
See Section 5.3, page 17 for drain installation instructions.

• Always operate this instrument at room temperature between 41°F and

122°F (5°C to 50°C). Allow sufficient air circulation by leaving at least
inches (15 cm) of clearance around the instrument.

• DO NOT overfill the bath. Overflowing liquid may damage the electrical

system. Be sure to allow for thermal expansion of the fluid as the bath
temperature increases. See Section 5.3, Bath Preparation and Filling,
specific instructions.

• DO NOT change the values of the bath calibration constants from the fac-

tory set values. The correct setting of these parameters is important to th
safety and proper operation of the unit.

• The refrigeration may be damaged or the lifetime shortened if the

set-point temperature is set above 60°C for more than one hour with the
refrigeration manually on. Ensure that the refrigeration is off when the
unit is used above 60°C.

• The Factory Reset Sequence should be performed only by authorized

personnel if no other action is successful in correcting a malfunction. You
must have a copy of the most recent Report of Test to restore the test pa­rameters.

4

6

for

e

1 Before You Start

• DO NOT operate this instrument in an excessively wet, oily, dusty, or

dirty environment.

• The unit is a precision instrument. Although it has been designed for opti-

mum durability and trouble free operation, it must be handled with
Position the unit before the tank is filled with fluid. Use the handles pro­vided to move the unit. Due to the weight of the compressor, it may re­quire two people to safely move the bath. If two people are used,

place
one person in the front and one person in the back of the unit, carefully
slide hands under the unit and lift in unison. The area containing the com­pressor will be heavier than the rest of the unit. Do not move a unit

with fluid.

• Most probes have handle temperature limits. Be sure that the probe handle

temperature limit is not exceeded in the air above the instrument.

• The instrument and any thermometer probes used with it are sensitive in-

struments that can be easily damaged. Always handle these devices with
care. Do not allow them to be dropped, struck, stressed, or overheated.

COLD BATHS

• Refrigerated baths require that the condensing coil be cleaned periodi-

cally. Accumulation of dust and dirt on the condenser will result in pre­mature failure of the compressor.

care.

filled

• This bath has been equipped with a brownout and over voltage protection

device as a safety feature to protect the system components.

• Mode of Operation: This bath needs to be plugged into the line voltage

for at least 2 minutes before operation. This is only necessary for the firs

t
time that the bath is energized or when it is moved from one location to
another. Turning the bath ON or OFF does not trigger the delay.

• If a High/Low voltage condition exists for longer than 5 seconds, the bath

de-energizes. An amber indicator on the back panel lights when this con­dition exists.

• Re-energization is automatic upon correction of the fault condition and af-

ter a delay cycle of about 2 minutes. If a fault condition exists upon appli­cation of power, the bath will not energize.

• Under and Over Voltage Protection at 115 VAC

♦

Voltage Cutout: ±12.5% (101 - 129 VAC)

♦

Voltage Cut In: ±7.5% (106 - 124 VAC)

• Under and Over Voltage Protection at 230 VAC

♦

Voltage Cutout: ±12.5% (203 - 257 VAC)

5

1 Before You Start

♦

Voltage Cut In: ±7.5% (213 - 247 VAC)

6

2 Introduction

2

Introduction

The Kaye Cold Temperature Reference is a bench-top constant temperature
bath useful in temperature calibration and other applications requiring stable
temperatures. An innovative state of the art solid-state temperature controller
has been incorporated which maintains the bath temperature with extreme sta­bility. The temperature controller uses a micro-controller to execute the many
operating functions.

User interface is provided by the 8-digit LED display and four key-switches.
Digital remote communications is standard with an RS-232 interface.

The CTR –40 bath was designed to be compact and low cost without compro­mising performance. The CTR –40 bath operates over a wide temperature range
from –40°C to 150°C. The refrigeration permits sub-ambient temperature
control.

The CTR –40 features:

• Rapid heating and cooling

• RS-232 (standard)

• Temperature scan rate control

• Ramp and soak functions

• Compact size

• Eight set-point memory

• Adjustable readout in °C or °F

• Automatic refrigeration control

7

2 Introduction

3

3.1

Specifications and Environmental Conditions

Specifications

Range

Stability (2 sigma)

Uniformity

Heating Time

Cooling Time
Stabilization Time

Temperature Setting

†

Set-point Resolution

Display Temperature Resolution

Digital Setting Accuracy

Digital Setting Repeatability

Heater

Access Opening

Depth

Wetted Parts

†

Power

Volume

Weight

Size

Safety

–40°C to 150°C
±0.005°C at –40°C (ethanol)

±0.005°C at 25°C (water)
±0.007°C at 150°C (5012 oil)

±0.006°C at –40°C (ethanol)
±0.005°C at 25°C (water)
±0.010°C at 150°C (5012 oil)

60 minutes, from 25°C to 150°C (5012 oil @ 115V)

110 minutes, from 25°C to –40°C (ethanol)
15-20 minutes

Digital display with push-button entry

0.01°; 0.00018° in high resolution

0.01°

±0.5°C

±0.01°C

1400 VA @ 115V (230V) Nominal

172mm x 94mm (6.8” x 3.7”)
234 mm (9.25”)
304 Stainless Steel

115 V ac (±10 %), 60 Hz, 15 A [230 V ac (±10 %), 50 Hz, 8 A optional], 1400 VA

Caution W

If the volt

age is outside ±10%, the compressor may be damaged.

back panel label for the correct voltage and frequency prior to energizing
the unit.

9.2 liters (2.4 gal.)

35.4 kg (78 lb.)

305 mm W x 622 mm D x 584 mm H (12” x 24.5” x 23”) (W x D x H)

IEC 61010-1; Overvoltage Category II, Pollution Degree 2; IEC 61010-2-010,

IEC 61010-2-011

Electromagnetic Compatibility

International ........................................IEC 61326-1: Basic Electromagnetic

Environment; CISPR 11: Group 1, Class A
Group 1: Equipment has intentionally generated and/or uses conductively-cou­pled radio frequency energy that is necessary for the internal function of the
equipment itself.
Class A: Equipment is suitable for use in all establishments other than domestic
and those directly connected to a low-voltage power supply network that supplies
buildings used for domestic purposes. There may be potential difficulties in
ensuring electromagnetic compatibility in other environments due to conducted
and radiated disturbances.
Caution: This equipment is not intended for use in residential environments and
may not provide adequate protection to radio reception in such environments.

Check the

Refrigeration

Interface Package

†

Rated at listed 115 V (or optional 230 V).

R-410A single stage

RS-232 included

9

3 Specifications and Environmental Conditions

3.2

Environmental Conditions

Although the instrument has been designed for optimum durability and trou­ble-free operation, it must be handled with care. The instrument should not be
operated in an excessively dusty or dirty environment. Maintenance and clean­ing recommendations can be found in the Maintenance Section of this manual.

The instrument operates safely under the following conditions:

• ambient temperature range: 5 °C to 35 °C (41 °F to 95 °F)

• ambient

creasing linearly to 50 % at 35°C

• pressure: 75kPa - 106kPa

• mains voltage within ±10% of nominal

• vibrations in the calibration environment should be minimized

• altitudes less than 2000 meters

• indoor use only

The Product can show some control sensitivity to moderate or severe
electromagnetic fields or conducted interference of certain frequencies. In
the presence of radiated EM disturbances, with frequencies of 250 MHz to
400 MHz and with amplitude >1 V/m to a maximum of 3 V/m, add

0.0025 °C to the stability specification. Stability is not guaranteed if
amplitude is >3 V/m. When subject to conducted disturbances of 8 MHz to
80 MHz, and amplitude >3 V, add 0.005 °C to the stability specification.

relative humidity: maximum 80% for temperatures < 31°C de-

Note

10

3.3

3.3.1

3.3.2

Hardware Warranty and Assistance

Instrument Warranty

Amphenol Thermometrics, Inc. warrants its products against defects in
materials and workmanship for a period of 12 months from the date of
shipment. Amphenol Thermometrics, Inc. will, at its option, repair or replace
products which prove defective during this warranty period provided
returned to our facility in St. Marys Pennsylvania, European warranty returns
are sent to Pforzheim, Germany. Repairs necessitated by misuse of this product
are not covered by this warranty. No other warranties are expressed or implied,
includ- ing but not limited to the implied warranties of merchantability and
fitness for a particular purpose. Amphenol Thermometrics, Inc. is not liable for
consequential damages.

In-Warranty Repairs

Customers are requested to discuss their problem with a Amphenol Advanced
Sensors to insure a prompt and accurate assessment of their needs. Frequently,
a problem can be resolved via phone or FAX with minimal inconvenience or
delay.

If necessary, the Customer Service Representative will send replacement parts
or authorize the return of the instrument to the factory for repair. Instruments

they are

3 Specifications and Environmental Conditions

serviced in this manner will be repaired, completely tested, and calibrated prior
to shipment.

When an instrument is returned to the factory, the customer must prepay the
freight charges. Amphenol Advanced Sensors will prepay freight charges for
the instrument's return via a comparable shipment method.

If Field Service is required under the warranty, the customer is responsible for
travel and living expenses incurred by the Field Service Representative.

3.3.3

3.3.4

3.3.5

After-Warranty Repairs

Customers are requested to discuss their problem with a Amphenol Advanced
Sensors Service Representative to insure a prompt assessment of their needs.
Frequently, a customer installed exchange part will solve the problem with
minimal inconvenience and expense.

Factory repairs can frequently be completed on a fixed price basis. A base ser­vice fee plus labor and materials will be charged in lieu of the fixed repair price
upon customer request or if extensive repairs are required.

Customers are requested to obtain a return authorization number prior to re­turning any instrument for service.

All instruments serviced at the factory will be repaired, updated, calibrated, and
completely tested prior to shipment.

Equipment Maintenance Agreements

An optional Equipment Maintenance Agreement provides an annual preventive
maintenance visit with certified recalibration, plus replacement parts through­out the year. Contact the Customer Service Department at [phone] for
details and prices. European customers contact the Customer Service Depart­ment at [phone].

Customer Support

Within 90 days of shipment from the factory, installation and initial configura­tion assistance will be provided by a Customer Service Representative via
phone or FAX at no charge.

After 90 days from shipment, technical assistance or consultation will be lim­ited to identification and resolution of instrument failures, unless a Customer
Support Agreement has been purchased.

11

3 Specifications and Environmental Conditions

3.3.6

3.3.7

Customer Support Agreement

An optional Customer Support Agreement provides additional phone or FAX
technical assistance for installation or program development. Contact the Cus­tomer Service Department for details.

Customer Site Assistance

Amphenol Advanced Sensors can provide optional onsite assistance with
installation, initial operation, and training of plant personnel. Contact the
Customer Service Department for details.

12

4 Quick Start

4

4.1

4.2

Quick Start

This chapter gives a brief summary of the steps required to set up and operate
the bath. This should be used as a general overview and reference and not as a
substitute for the remainder of the manual. Please read Section 5, Installation,
through Section 7, General Operation, carefully before operating the bath.

Unpacking

Unpack the bath carefully and inspect it for any damage that may have oc­curred during shipment. If there is shipping damage, notify the carrier immedi­ately. Verify that all components are present:

• CTR –40 Bath

• Access Hole Cover

• Manual

• RS-232 Cable

• Report of Test

• Drain Valve

Set Up

Caution: The drain valve must be installed on the back of the bath before

attempting to fill the tank with fluid. See Section 5.3, page 17 for drain in­stallation instructions.

strument is equipped with a soft cutout (user settable firm-

Warning: The

ware) and a hard cutout (set at the factory). Check the flash point, boiling
point, or other fluid characteristic applicable to the circumstances of the
unit operation. Ensure that the soft cutout is adjusted to the fluid charac­teristics of the application. As a guideline, the soft cutout should be set
10°C to 15°C below the flash point of the bath fluid. See Section 7.1, Heat
Transfer Fluid, for specific information on bath fluids and Section 8.10,
Cutout.

Set up of the bath requires careful unpacking and placement of the bath, install­ing the drain valve, filling the bath with fluid, and connecting power. Consult
Section 5, Installation, for detailed instructions for proper installation of the
bath. Install the drain valve onto the pipe fitting at the back of the bath and

in

13

4 Quick Start

make sure the valve is closed. See Section 5.3, Bath Preparation and Filling. Be
sure to place the bath in a safe, clean and level location.

Fill the bath tank with an appropriate liquid. Be sure to select the correct fluid
for the temperature range of the calibration. Bath fluids should be selected to
operate safely with adequate thermal properties to meet the application require­ments. For operation at moderate bath temperatures, clean distilled water works
well. Carefully pour the fluid into the bath tank through the large rectangular
access hole above the tank avoiding spilling any fluid. The fluid must not ex­ceed a height of 12.7–20.3 mm (0.5–0.8 inches) below the bottom of the lid
(NOT the access cover).

Note: As the temperature of the bath increases the fluid level will increase, see
Section 7.1.5 on page 24.

4.3

4.4

Power

Plug the bath power cord into a mains outlet of the proper voltage, frequency,
and current capability. Refer to Section 3.1, Specifications, for power details.
Refer to and read the CAUTION at the front of the manual concerning brown­out and over voltage protection. Check the back panel label for the correct
voltage and frequency prior to energizing the unit. Turn the bath on using
the front panel “POWER” switch. The bath will turn on and begin to heat or
cool to reach the previously programmed temperature set-point. The front panel
LED display will indicate the actual bath temperature. Set the cooling switch to
“ON” for below or near ambient temperatures.

Note: The actual temperature where cooling is required depends on the bath
fluid and whether a cover is used over the access well.

Setting the Temperature

In the following discussion and throughout this manual a solid box around the
word SET, UP, DOWN or EXIT indicates the panel button to press while the
dotted box indicates the display reading on the front panel. Explanation of the
button function or display reading is written at the right.

To view or set the bath temperature set-point proceed as follows. The front
panel LED display normally shows the actual bath temperature.

24.68 C

Bath temperature display

14

th

When “SET” is pressed the display shows
rently being used and its value. Eight set-point memories are available.

S

Access set-point selection

e set-point memory that is cur-

4 Quick Start

1. 25.0

Press “SET” to select this memory and access the

S

C 25.00

Press “UP” or “DOWN” to change the set-point value.

U

C 30.00

Press SET to accept the new value and display
gins heating or cooling to the new set-point.

S

0.00000

Press “EXIT” and the bath temperatu

E

24.73 C

Set-point 1, 25.0°C currently used

Access set-point value

Current value of set-point 1, 25.00°C

Increment display

New set-point value

Store new set-point, access vernier

Current vernier value

will be displayed again.

re

Return to the temperature display

Bath temperature display

set-point value.

the vernier value. The bath be-

The bath heats or cools until it reaches the new set-point temperature. Turn off
the cooling to reach an

When setting the set-point temperature be careful not to exceed the temperature
limit of the bath fluid. The over-temperature cutout should be correctly set for
added safety. See Section 8.10, Cutout.

To obtain optimum control stability adjust the proportional band as discussed in
Section 8.9, Proportional Band.

d control at higher temperatures.

15

5 Installation

5

5.1

5.2

Installation

Bath Environment

The CTR –40 Bath is a precision instrument, which should be located in an ap­propriate environment. The location should be free of drafts, extreme tempera­tures and temperature changes, dirt, etc. The surface where the bath is placed
must be level. Allow plenty of space around the bath for air circulation.

The top surface of the bath may become hot at high temperatures. Beware of
the danger of accidental fluid spills.

A fume hood should be used to remove any vapors given off by hot bath fluid.

“Dry-out” Period

If this equipment is used in a manner not specified by the manufacturer, the
protection provided by the equipment may be impaired.

Before initial use, or after transport, or after storage in humid or semi-humid
environments, or anytime the bath has not been energized for more than 10
days, the instrument needs to be energized for a "dry-out" period of 2 hours be­fore it can be assumed to meet all of the safety requirements of the IEC 1010-1.
If the product is wet or has been in a wet environment, take necessary measures
to remove moisture prior to applying power such as storage in a low humidity
temperature chamber operating at 50 degree centigrade for 4 hour or more.

5.3

5.3.1

Bath Preparation and Filling

Caution: Before filling the tank with fluid the drain valve must be installed

onto the fitting at the back of the bath.

Drain Valve Installation Instructions

The drain valve attaches to the swage fitting located on the lower backside of
the bath. (See Figure 1.)

1. Place the valve onto the drain fitting and hand tighten in place by turn­ing the hex nut (attached to the bath) counter clockwise while holding
the valve stationary.

2. Using open-end wrenches, hold the valve in place and tighten the he
nub one quarter turn from the hand tightened position above.

The valve should be secured in place at this point. If not, repeat step number 2
being careful not to over tighten the assembly.

x

17

5 Installation

Ensure the valve handle is in the closed position before attempting to add fluid
to the tank.

Figure 1

Drain Valve Installation —IMPORTANT: Do Not Over Tighten. Follow

the installation instructions above.

18

5.3.2

Filling With Fluid

The CTR –40 Bath is not provided with a fluid. Depending on the desired tem­perature range, any of the following fluids, as well as others, may be used in
the bath:

• Water

• Ethylene glycol/water

• Mineral oil

• Silicone oil

Fluids are discussed in detail in Section 7.1, Heat Transfer Fluid, on page 23.

Remove any access hole cover from the bath and check the tank for foreign
matter (dirt, remnant packing material, etc.).

Fill the bath with clean unpolluted fluid. Fill the bath carefully through the
large rectangular access hole to a level that will allow for stirring and thermal
expansion. Section 7.1.5, Thermal Expansion, explains fluid expansion. DO
NOT turn on the bath without fluid in the tank. Maximum and minimum fill
levels are indicated on the slotted baffle inside the tank. Carefully monitor the

5 Installation

bath fluid level as the bath temperature rises to prevent overflow or splashing.
Remove excess hot fluid if necessary with caution.

5.4

Figure 2

Tank Baffle Showing Minimum and Maximum Fill Levels

Power

With the bath power switch off, plug the bath into an AC mains outlet of the
appropriate voltage, frequency, and current capacity. Refer to Section 3.1,
Specifications, for power details. Refer to and read the CAUTION at the front
of the manual concerning brownout and over voltage protection. Check the

back panel label for the correct voltage and frequency prior to energizing
the unit.

19

1

t

6 Parts and Controls

6 Parts and Controls

6.1

Front Panel

The following controls and indicators are present on the controller front panel
(see Figure 3 below): (1) the digital LED display, (2) the control buttons, (3)
the bath on/off power switch, (4) the control indicator light, and (5) the cooling
on/off switch.

4

Figure 3

Front Panel

1. The digital display is an important part of the temperature controller. It dis-

plays the set-point temperature and bath temperature as well as the various
other bath functions, settings, and constants. The display shows temperatures
according to the selected scale units °C or °F.

Set Exi

2

CTR –40

O

3

5

O

2. The control buttons (SET, DOWN, UP, and EXIT) are used to set the bath

temperature set-point, access and set other operating parameters, and access
and set bath calibration parameters. A brief description of the functions of the
buttons follows:

SET - Used to display the next parameter in a menu and to set parameters to the
displayed value.

DOWN - Used to decrement the displayed value of parameters.

UP - Used to increment the displayed value.

EXIT - Used to exit from a menu. When EXIT is pressed any changes made to
the displayed value will be ignored.

3. The on/off switch controls power to the entire bath including the stirring

motor.

4. The control indicator is a two color light emitting diode (LED). This indica-

tor lets the user visually see the ratio of heating to cooling. When the indicator

20

6 Parts and Controls

is red the heater is on, and when it is green the heater is off and the bath is
cooling.

5. The cooling switch turns on the refrigeration for control below 50°C and
rapid cool down. The cooling shuts off automatically above 60°C. Manually
turn off the refrigeration at temperatures where it has been determined to be un­necessary. See Sections 7.6, Refrigeration, 8.13.2, Cooling Mode, and 8.13
Hot Gas Bypass Mode.

.3,

6.2

Bath Tank and Lid

The bath tank and lid assembly includes: the tank, the control probe, the stir­ring motor, the access hole, and the access hole cover. The stirring motor cover,
covers the stirring motor, cooling fan, and control probe.

• The bath tank is constructed of stainless steel. It is very resistant to oxida-

tion in the presence of most chemicals and over a wide range of tempera­tures.

• The control probe provides the temperature feedback signal to the con-

troller allowing the controller to maintain a constant temperature. Th
control probe is a precision platinum resistance thermometer (PRT). It is
delicate and must be handled carefully. The probe is placed in the small
hole in the top of the bath so that the probe tip is fully immersed in the
bath fluid.

• The stirring motor is mounted on the bath tank lid. It drives the stirring

propeller to provide mixing of the bath fluid. Proper mixing of the fluid is
important for good constant temperature stability.

• On the bath lid is a large access hole. This is used for filling the bath

fluids and placement of thermometers and devices into the bath. When
possible the access hole should be covered.

• An access hole cover should be used to cover the access opening in the

top of the bath. This improves bath temperature stability,
fluid evaporation or fumes and increases safety with hot fluid. The user
may drill or cut holes in the cover to accommodate the instruments to be
calibrated or immersed in the bath. Spare covers are available from
Amphenol Advanced Sensors.

e

with

prevents excess

22

6.3

Back Panel

On the back of the bath are the system fuses, removable power cord, high/low
voltage indicator, drain, and serial port.

7 General Ope ration

7 General Operation

7.1

7.1.1

Heat Transfer Fluid

Many fluids will work with CTR –40 bath. Choosing a fluid requires consider­ation of many important characteristics of the fluid. Among these are tempera­ture range, viscosity, specific heat, thermal conductivity, thermal expansion,
electrical resistivity, fluid lifetime, safety, and cost.

Temperature Range

One of the most important characteristics to consider is the temperature range
of the fluid. Few fluids work well throughout the entire temperature range of
the bath. The temperature at which the bath is operated must always be within
the safe and useful temperature range of the fluid used. The lower temperature
range of the fluid is determined either by the freeze point of the fluid or the
temperature at which the viscosity becomes too great. The upper temperature is
usually limited by vaporization, flammability, or chemical breakdown of the
fluid. Vaporization of the fluid at higher temperatures may adversely affect
temperature stability because of cool condensed fluid dripping into the bath
from the lid.

The bath temperature should be limited by setting the safety cutout (see Section

8.10, Cutout) or the high limit (see Section 8.15, Calibration Parameters) so

that the bath temperature cannot exceed the safe operating temperature limit of
the fluid.

7.1.2

Viscosity

Viscosity is a measure of the thickness of a fluid or how easily it can be poured
and mixed. Viscosity affects the temperature uniformity and stability of the
bath. With lower viscosity fluid mixing is better. This creates a more uniform
temperature throughout the bath. This improves the bath response time allow­ing it to maintain a more constant temperature. For good control the viscosity
should be less than 10 centistokes. 50 centistokes is the practical upper limit of
allowable viscosity. Viscosity greater than this causes very poor control stabil­ity because of poor stirring and may also overheat or damage the stirring motor.
Viscosity may vary greatly with temperature, especially with oils.

When using fluids with higher viscosities the controller proportional band (see
Section 8.9, Proportional Band) may need to be increased to compensate for the
reduced response time. Otherwise the temperature may begin to oscillate.

23

7 General Ope ration

7.1.3

7.1.4

7.1.5

Specific Heat

Specific heat is the measure of the heat storage ability of the fluid. Specific
heat, to a small degree, affects the control stability and the heating and cooling
rates. Generally, a lower specific heat means quicker heating and cooling. The
proportional band may require some adjustment depending on the specific heat
of the fluid.

Thermal Conductivity

Thermal conductivity measures how easily heat flows through the fluid. Ther­mal conductivity of the fluid affects the control stability, temperature unifor­mity, and temperature settling time. Fluids with higher conductivity distribute
heat more quickly and evenly improving bath performance.

Thermal Expansion

Thermal expansion describes how much the volume of the fluid changes with
temperature. Thermal expansion of the fluid must be considered since the in­crease in fluid volume as the bath temperature increases may cause overflow. It
may be dangerous to permit the fluid to overflow the tank. It may also cause
loss of valuable bath fluid. Excessive thermal expansion may also be undesir­able in applications where constant liquid level is important.

Thermal expansion coefficients of several fluids are shown in Table 2 on page

. Fluid manufacturers can also provide this information. The thermal expan-

28
sion coefficients are shown in units of cm/cm/°C. However, the values are the
same for any unit of length. Divide the value by 1.8 for °F coefficients. The fol­lowing equation may be used to find the desired depth:

24

= DS [K(TE–TS)+1]

D

E

Or

Where:

= DE / [K(TE–TS)+1] where D

D

S

≤ The Maximum Fill Depth

E

K=Expansion coefficient

T

=Ending temperature

E

=Starting temperature

T

S

=Ending depth

D

E

=Starting depth

D

S

The maximum fill depth is typically 0.5 to 0.8 inches below the level of the
gasket at the top of the bath tank (not the top of the bath lid). Judgement must
be made with different stirring arrangements to prevent splashing on the gasket
or lid of the bath.

7 General Ope ration

Example:

The final depth of Dow Corning 710 silicone oil in the bath tank is to be 9.2
inches when heated from 25 to 300°C. What should the starting depth be?

Expansion coefficient for 710 oil on Table 2, K= 0.00077 inch/inch/°C

7.1.6

7.1.7

7.1.8

Ending temperature, T

Starting temperature, T

Ending depth, D

D

= 9.2/[0.00077 (300-25) + 1] = 7.59 inches

S

E

Electrical Resistivity

Electrical resistivity describes how well the fluid insulates against the flow of
electric current. In some applications, such as measuring the resistance of bare
temperature sensors, it may be important that little or no electrical leakage oc­cur through the fluid.

In such conditions choose a fluid with very high electrical resistivity.

Fluid Lifetime

Many fluids degrade over time because of vaporization, water absorption, gel­ling, or chemical break-down. Often the degradation becomes significant near
the upper temperature limit of the fluid, substantially reducing the fluid’s
lifetime.

Safety

When choosing a fluid always consider the safety issues associated. Obviously
where there are extreme temperatures there can be danger to personnel and
equipment. Fluids may also be hazardous for other reasons. Some fluids may
be considered toxic. Contact with eyes, skin, or inhalation of vapors may cause
injury. A proper fume hood must be used if hazardous or bothersome vapors
are produced.

= 300°C

E

= 25°C

S

= 9.2 inches

at high temperatures may pose danger from BURNS,

Warning: Fl

FIRE, and TOXIC FUMES. Use appropriate caution and safety equip­ment.

Fluids may be flammable and require special fire safety equipment and proce­dures. An important characteristic of the fluid to consider is the flash point. The
flash point is the temperature at which there is sufficient vapor given off so that
when there is adequate oxygen present and an ignition source is applied the va-

uids

25

7 General Ope ration

por will ignite. This does not necessarily mean that fire will be sustained at the
flash point. The flash point may be either of the open cup or closed cup type.
Either condition may occur in a bath situation. The open cup flash point is mea­sured under the condition of vapors escaping the tank. The closed cup flash
point is measured with the vapors being contained within the tank. Since oxy­gen and an ignition source is less available inside the tank the closed cup flash
point will be lower than the open cup flash point.

Environmentally hazardous fluids require special disposal according to applica­ble federal or local laws after use.

7.1.9

7.1.10

7.1.10.1

Cost

Cost of bath fluids may vary greatly, from cents per gallon for water to hun­dreds of dollars per gallon for synthetic oils. Cost may be an important consid­eration when choosing a fluid.

Commonly Used Fluids

Below is a description of some of the more commonly used fluids and their
characteristics.

Water

Water is often used because of its very low cost, its availability, and its excel­lent temperature control characteristics. Water has very low viscosity and good
thermal conductivity and heat capacity, which make it among the best fluids for
good control stability at lower temperatures. Temperature stability is much
poorer at higher temperatures because water condenses on the lid, cools and
drips into the bath. Water is safe and relatively inert. The electrical conductivity
of water may prevent its use in some applications. Water has a limited tempera­ture range, from a few degrees above 0°C to a few degrees below 100°C. At
higher temperatures evaporation becomes significant. Water used in the bath
should be distilled or deionized to prevent mineral deposits. Consider using an
algicide chemical in the water to prevent contamination.

Note: Water used at temperatures greater than 75°C (167°F) may have stability
problems.

26

7.1.10.2

Ethylene Glycol

The temperature range of water may be extended by using a solution of one
part water and one part ethylene glycol (antifreeze). The characteristics of the
ethylene glycol-water solution are similar to water but with higher viscosity.
Use caution with ethylene glycol since this fluid is very toxic. Ethylene glycol
must be disposed of properly.

7 General Ope ration

7.1.10.3

7.1.10.4

7.1.11

Mineral Oil

Mineral oil or paraffin oil is often used at moderate temperatures above the
range of water. Mineral oil is relatively inexpensive. At lower temperatures
mineral oil is quite viscous and control may be poor. At higher temperatures
vapor emission becomes significant. The vapors may be dangerous and a fume
hood should be used. As with most oils, mineral oil expands as temperature in­creases. Be careful not to fill the bath too full to avoid overflows when heated.
The viscosity and thermal characteristics of mineral oil is poorer than water so
temperature stability will not be as good. Mineral oil has very low electrical
conductivity. Use caution with mineral oil since it is flammable and may also
cause serious injury if inhaled or ingested.

Silicone Oil

Silicone oils are available which offer a much wider operating temperature
range than mineral oil. Like most oils, silicone oils have temperature control
characteristics, which are somewhat poorer than water. The viscosity changes
significantly with temperature and thermal expansion also occurs. These oils
have very high electrical resistivity. Silicone oils are fairly safe and non-toxic,
but can be fairly expensive.

Fluid Characteristics Charts

Table 2 and Figure 4 on pages 28 and 29 have been created to provide help in
selecting a heat exchange fluid media for your constant temperature bath.
These charts provide both a visual and numerical representation of most of the
physical qualities important in making a selection. The list is not all inclusive.
There may be other useful fluids not shown in this listing. The charts include
information on a variety of fluids, which are often used as heat transfer fluid in
baths. Because of the temperature range some fluids may not be useful with
your bath.

7.1.11.1

Limitations and Disclaimer

The information given in this manual regarding fluids is intended only to be
used as a general guide in choosing a fluid. Though every effort has been made
to provide correct information we cannot guarantee accuracy of data or assure
suitability of a fluid for a particular application. Specifications may change and
sources sometimes offer differing information. Amphenol Advanced Sensors
cannot be liable for any personal injury or damage to equipment, product or
facilities resulting from the use of these fluids. The user of the bath is
responsible for collecting correct in- formation, exercising proper judgment,
and insuring safe operation. Operating near the limits of certain properties
such as the flash point or viscosity can compromise safety or performance.
Your company’s safety policies regarding

27

Table 2

)

Table of Various Bath Fluids and Their Properties

7 General Ope ration

Halocarbon 0.8
#5019

Methanol

Water

Ethylene
Glycol—50%
#5020

Mineral Oil No.7
#5011

Silicone Oil Type

200.05 #5010

Silicone Oil Type

200.10 #5012

Silicone Oil Type 10°C (v) 230°C (fl, cc)

200.20 #5013 0.393 @ 100°C

Silicone Oil Type 30°C (v) 278°C (fl, cc)

200.50 #5014

Silicone Oil Type 550 70°C (v) 230°C (fl, cc)
#5016

Silicone Oil Type 710 80°C (v)
#5017

Silicone Oil Type 66°C (v) 313°C (fl, oc)
210-H 14@204°C 1 @ 150°

Heat Transfer Salt
#5001

*Limiting Factors — b - boiling point e - high evaporation fl - flash point fr - freeze point v - viscosity — Flash point test oc = open cup cc = closed cup
**Very low water solubility, ice will form as a slush from condensation below freezing.

–100°C (v)** 70°C (e)

–96°C (fr)

0°C (fr)

–30°C (fr)

10°C (v)

–40°C (v)** 130°C (fl, cc)

–30°C (v)** 209°C (fl, cc)

180°C (fr)

10°C (fl,cc) 12°C

95°C (b)

90°C (b)

166°C (fl)

300°C(fl, oc

300°C (fl, oc)

550°C NONE

NONE 5.7 @ –50°C

0.8 @ 40°C

0.5 @ 70°C

1.3 @ –35°C

0.66 @ 0°C

0.45 @ 20°C

NONE 1 @ 25°C 1.00 1.00 0.0014

0.4 @ 75°C

7 @ 0°C

NONE

2 @ 50°C

0.7 @ 100°C

168°C

15 @ 75°C
5 @ 125°C

133°C 5 @ 25°C

211°C

10 @ 25°C
3 @ 135°C

232°C 20 @ 25°C

280°C

50 @ 25°C

232°C

50 @ 70°C
10@104°C

302°C 50 @ 80°C

7 @ 204°C

315°C

50 @ 66°C

34 @ 150°C

6.5 @ 300°C

2.4 @ 500°C 1.7 @ 500°C

1.71 @ 40°C

0.810 @ 0°C

0.792 @ 20°C

1.05 0.8 @ 0°C 0.001

0.87 @ 25°C 0.48 @ 25°C

0.84 @ 75°C 0.53 @ 75°C

0.81@125°C 0.57@125°C

0.92 @ 25°C

0.934 @ 25°C 0.43 @ 40°C 0.00032 @ 25°C 0.0 0108 1000 @ 25°C

0.949 @ 25°C 0.370 @ 40°C 0.00034 @ 25°C 0.00107 1000 @ 25°C

0.96 @ 25°C

1.07 @ 25°C 0.358 @ 40°C 0.00035 @ 25°C 0.0 0075

1.11 @ 25°C 0.363 @ 40°C 0.00035 @ 25°C 0.00077

0.96 @ 25°C 0.34 @ 100°C

2.0 @ 150°C

1.9 @ 300°C

0.2

0.6

0.4

0.45 @ 100°C

0.482 @200°C

0.420 @200°C

0.4

0.386 @ 100°C

0.433 @200°C

0.454 @ 100°C

0.505 @200°C

0.33 0.0014 0.00041

0.0004 0.0011

0.0005 @ 20°C 0.0014 @ 25°C

0.00025 @ 25°C 0.0007 @ 50°C 5 @ 25°C

0.00028 @ 25°C 0.00105 1000 @ 25°C

0.00037 @ 25°C 0.00104 1000 @ 25°C

0.0003 0.00095 100 @ 25°C

0.0002 @ 25°C

10 @ 150°C

50 @ 150°C

50 @ 150°C

50 @ 150°C

100 @ 25°C
1 @ 150°C

100 @ 25°C
1 @ 150°C

1.7 Ω /cm

C

3

flash points, toxicity, and such issues must be considered. You are responsible
for reading the MSDS (material safety data sheets) and acting accordingly.

7.1.11.2

About the Graph

The fluid graph visually illustrates some of the important qualities of the fluids
shown.

28

7 General Ope ration

PP

PP

Figure 4

Chart of Various Bath Fluids and Their Properties

Temperature Range: The temperature scale is shown in degrees Celsius. The
shaded bands indicate the fluids’ general range of application. Qualities includ­ing pour point, freeze point, important viscosity points, flash point, boiling
point and others may be shown.

Freezing Point: The freezing point of a fluid is an obvious limitation to stir­ring. As the freezing point is approached high viscosity may also limit
performance.

29

7 General Ope ration

Pour Point: This represents a handling limit for the fluid.

Viscosity: Points shown are at 50 and 10 centistokes viscosity. When viscosity

is greater than 50 centistokes stirring is very poor and the fluid is unsatisfactory
for bath applications. Optimum stirring generally occurs at 10 centistokes and
below.

Fume Point: Indicates the point at which a fume hood should be used. This
point is very subjective in nature and is impacted by individual tolerance to dif­ferent fumes and smells, how well the bath is covered, the surface area of the
fluid in the bath, the size and ventilation of the facility where the bath is located
and other conditions. This is also subject to company policy. In the graph we
assume the bath is well covered at this point.

Flash Point: The point at which ignition may occur. The point shown may be
either the open or closed cup flash point. Refer to the flash point discussion in
Section 7.1.8, Safety.

Boiling Point: At or near the boiling point of the fluid the temperature stability
is difficult to maintain. Fuming or evaporation is excessive. Large amounts of
heater power may be required to maintain the temperature because of the heat
of vaporization.

Decomposition: The temperature may reach a point at which decomposition of
the fluid begins. Further increasing the temperature may accelerate decomposi­tion to the point of danger or impracticality.

30

7.2

7.3

Stirring

Stirring the bath fluid is very important for stable temperature control. The
fluid must be mixed well for good temperature uniformity and fast controller
response. The stirrer is precisely adjusted for optimum performance.

Power

Power to the bath is provided by an AC mains supply. Refer to Section 3.1,
Specifications, for power details. Refer to and read the CAUTION at the front
of the manual concerning brownout and over voltage protection. Check the

back panel label for the correct voltage and frequency prior to energizing
the unit. Power to the bath passes through a filter to prevent switching spikes

from being transmitted to other equipment.

To turn on the bath press the control panel power switch to the ON position.
The stirring motor will turn on, the LED display will begin to show the bath
temperature, and the heater will turn on or off until the bath temperature
reaches the programmed set-point.

7 General Ope ration

When powered on the control panel display will briefly show a four digit num­ber. This number indicates the number of times power has been applied to the
bath. Also briefly displayed is data, which indicates the controller hardware
configuration. This data is used in some circumstances for diagnostic purposes.

7.4

7.5

Heater

The temperature controller precisely controls the bath heater to maintain a con­stant bath temperature. Power is controlled by periodically switching the heater
on for a certain amount of time using a solid-state relay.

The front panel red/green control indicator shows the state of the heater. The
control indicator glows red when the heater is on and green when the heater is
off. The indicator pulses at a constant rate when the bath is maintaining a stable
temperature.

Temperature Controller

A unique hybrid digital/analog temperature controller controls the bath temper­ature. The controller offers the tight control stability of an analog temperature
controller as well as the flexibility and programmability of a digital controller.

The bath temperature is monitored using a platinum resistance sensor as the
control probe. The signal is electronically compared with the programmable
reference signal, amplified, and then passed to a pulse-width modulator circuit
that controls the amount of power applied to the bath heater. The bath is opera­ble within the temperature range given in the specifications. For protection
against a solid-state relay failure or other circuit failure, the micro-controller
automatically turns off the heater with a second mechanical relay anytime the
bath temperature is more than a certain amount above the set-point temperature.
In addition to this protection, the controller is also equipped with a separate
thermocouple temperature monitoring circuit that shuts off the heater if the
temperature exceeds the cutout set-point.

The controller allows the operator to set the bath temperature with high resolu­tion, set the cutout temperature, adjust the proportional band, monitor the
heater output power, and program the controller configuration and calibration
parameters. The controller may be operated in temperature units of degrees
Celsius or Fahrenheit. The controller is operated and programmed from the
front control panel using the four key switches and digital LED display. Re­mote digital operation with the controller is possible via the standard RS-232
serial port. Operation of the controller using the front control panel is discussed
following in Section 8, Controller Operaton. Operation using the digital inter­face is discussed in Section 9, Digital Communication Interface.

When the controller is set to a new set-point, the bath heats or cools to the new
temperature. Once the new temperature is reached, the bath usually takes 15–20

31

7 General Ope ration

minutes for the temperature to settle and stabilize. There may be a small over­shoot or undershoot of about 0.5°C during this process.

7.6

Ref rigeration

Cooling is provided by a compact refrigeration system utilizing the ozone safe
R-410A HFC refrigerant. Refrigeration is often not needed when the bath is
above 45 to 60°C. The automated system automatically turns the system off
when above 60°C. The refrigeration system automatically changes modes de­pending upon bath temperature and operation needs as described below. The re­frigeration system is activated when the switch on the front panel is turned on.

If the bath is below the 60°C cutoff point and is set to a temperature above
60°C, the refrigeration shuts off to protect it from overheating and creating ex­cessive internal pressures. If the bath is above 60°C and is set to a new temper­ature below the cutoff temperature, the refrigeration turns on again at 59°C.

When the bath is controlling at temperatures between the 60°C and 0°C, the
bath operates in a low cooling capacity mode with the hot gas bypass valve on
(HGb on). The HGb system reduces the cooling capacity and helps to improve
the bath stability within that temperature range. Since more cooling capacity is
generally required below 0°C, the hot gas bypass is turned off (HGb off) pro­viding more cooling capacity.

When the bath is cooled from temperatures below the cutoff point to 0°C and if
the new set-point is at least 2°C below the current bath temperature, the cooling
turns to maximum capacity (HGb off) until the bath is within about 0.5°C of
the new set-point. This provides the fastest cooling possible to achieve the new
set-point temperature. As indicated, the cooling is always maximum below
0°C.

32

When heating the bath from temperatures of –40°C and the new set-point is at
least 10°C above the current bath temperature, the refrigeration turns off until
the bath is about 1°C below the new set-point. This permits the maximum heat­ing rate to reach the higher temperatures as quickly as possible. The cooling re­mains off at temperatures above 60°C.

The automatic cooling mode may not be ideal for all circumstances. The auto­matic mode may be turned off permitting manual control. These controls are
available through the front panel as described in Section 8.13, Operating Pa­rameters, or through the digital interface as described in Sections 9.2, Interface
Commands and 9.3, Cooling Control. The cooling mode control may be set to
automatic, on, or off. With these selections the refrigeration is either in auto­matic as described above, always on, or always off. The hot gas bypass modes
are similarly selectable between automatic, on, or off. This system is either in
automatic as described above, always on (low cooling capacity) or always off
(high cooling capacity).

7 General Ope ration

The following situations benefit by changing cooling modes.

• If the scan mode has been selected and the desired cooling scan requires

maximum cooling capacity in a range where the hot gas bypass would
normally be on.

• The application requires maximum cooling capacity when the hot gas by-

pass would normally be on.

• When using the bath at temperatures below 0°C in an ambient of less than

23°C, a small benefit to stability may be realized by using the hot gas by­pass.

• The refrigeration may be beneficially used for short times (less than one

hour) above 60°C but less than 100°C.

This list is not intended to be complete, but only suggests some of the situa­tions when automatic modes may not be best. Most of the time, the automatic
functions are adequate and should be used.

33

8 Controller Operation

8 Controller Operation

This chapter discusses in detail how to operate the bath temperature controller
using the front control panel. Using the front panel key switches and LED dis­play the user may monitor the bath temperature, set the temperature set-point in
degrees C or F, monitor the heater output power, adjust the controller propor­tional band, set the cutout set-point, and program the probe calibration parame­ters, operating parameters, serial interface configuration, and controller
calibration parameters. Operation is summarized in Figure 5 on page 36.

8.1

8.2

Bath Temperature

The digital LED display on the front panel allows direct viewing of the actual
bath temperature. This temperature value is what is normally shown on the dis­play. The units, C or F, of the temperature value are displayed at the right. For
example,

25.00 C

The temperature display function may be accessed from any other function by

ng

pressi

the “EXIT” button.

Reset Cutout

Bath temperature in degrees Celsius

If the over-temperature cutout has been triggered then the temperature display
will alternately flash,

Cut-out

The message continues to flash between the actual temperature and

the temperature is reduced and the cutout is reset.

until

The cutout has two modes — automatic reset and manual reset. The mode de­termines how the cutout is reset which allows the bath to heat up again. When
in automatic mode, the cutout will reset itself as soon as the temperature is low­ered below the cutout set-point. With manual reset mode the cutout must be re­set by the operator after the temperature falls below the set-point.

When the cutout is active and the cutout mode is set to manual (“reset”) then
the display will flash “cutout” until the user resets the cutout. To access the re­set cutout function press the “SET” button.

S

The display indicates the reset function.

Indicates cutout condition

Access cutout reset function

Cut-out

35

8 Controller Operation

T

Figure 5

Controller Operation Flowchart

36

Calibration

Menu

SET

X 5

CTO

SET

EXIT

C0

SET

EXIT

CG

H

SET EXIT

L

HGbt

EXIT

Linefeed

MANUAL

SEE

SEE

.

MANUAL

.

SET EXIT

UE

UES

S

AL
V

AL
V

THESE

THESE

CHANGE

CHANGE

T

T

NO

SET EXIT

DO

NO
DO

SET

Adj. bt

SET/EXIT

8 Controller Operation

8.3

8.3.1

rESEt ?

Press “SET” once more to reset the cutout.

S

This action switches the display to the set temperature function. To return to
displaying the temperature display press the “EXIT” button. If the cutout is still
in the over-temperature fault condition, the display continues to flash “cutout”.
The bath temperature must drop a few degrees below the cutout set-point be­fore the cutout can be reset.

Temperature Set-point

The bath temperature can be set to any value within the range and with resolu­tion as given in the specifications. The operator must know the temperature
range of the particular fluid used in the bath and the bath should only be oper­ated well below the upper temperature limit of the liquid. In addition, the cutout
temperature should also be set below the upper limit of the fluid.

Setting the bath temperature involves three steps: 1) selecting the set-point
memory, 2) adjusting the set-point value, and 3) adjusting the vernier, if
desired.

Programmable Set-points

Cutout reset function

Reset cutout

The controller stores 8 set-point temperatures in memory. The set-points can be
quickly recalled to conveniently set the bath to a previously programmed tem­perature set-point.

To set the bath temperature one must first select the set-point memory. This
function is accessed from the temperature display function by pressing “SET”.
The number of the set-point memory currently being used is shown at the left
on the display followed by the current set-point value.

25.00 C

S

1.

To change the set-point memory press “UP” or “DOWN”.

U

4.

Bath temperature in degrees Celsius

Access set-point memory

25.0

Set-point memory 1, 25.0°C currently used

Increment memory

40.0

New set-point memory 4, 40.0°C

37

8 Controller Operation

Press “SET” to accept the new selection and access the set-point value.

S

8.3.2

Set-point Value

After selecting the set-point memory and pressing “SET”, the set-point value
may be adjusted in increments of 0.01° (C or F). The set-point value is dis­played with the units, C or F, at the left.

C

If the set-point value does not need to be changed, press “EXIT” to resume dis­playing the bath temperature. Press “UP” or “DOWN” to adjust the set-point
value.

U

C

When the desired set-point value is reached, press “SET” to accept the new
value and access the set-point vernier. If “EXIT” is pressed, any changes made
to the set-point are ignored.

S

8.3.3

Set-point Vernier

Accept selected set-point memory

40.00

Set-point 4 value in °C

Increment display

42.50

New set-point value

Accept new set-point value

The user may want to adjust the set-point slightly to achieve a more precise
bath temperature. The set-point vernier allows one to adjust the temperature be­low or above the set-point by a small amount with very high resolution. Each of
the 8 stored set-points has an associated vernier setting. The set-point vernier
can be set in increments of 0.00018°C. The vernier is accessed from the
set-point by pressing “SET”. The vernier setting is displayed as a 6 digit num­ber with five digits after the decimal point. This is a temperature offset in de-

38

grees of the selected units, C or F.

0.00000

To adjust the vernier, press “UP” or “DOWN”. Unlike most functions the ver­nier setting has immediate effect as the vernier is adjusted. “SET” need not be
pressed. This allows the bath temperature to be continually adjusted as it is
displayed.

U

Current vernier value in °C

Increment display

8 Controller Operation

8.4

8.4.1

0.00090

Next press “EXIT” to return to the temperature display or “SET” to access the
temperature scale units selection.

S

Scan

The scan rate can be set and enabled so that when the set-point is changed the
instrument heats or cools at a specified rate (degrees per minute) until it reaches
the new set-point. With the scan disabled the instrument heats or cools at the
maximum possible rate.

Scan Control

The scan is controlled with the scan on/off function that appears in the main
menu after the set-point function.

ScAn=OFF

Press “UP” or “DOWN” to toggle the scan on or off.

ScAn=On

Press “SET” to accept the present setting and continue.

New vernier setting

Access scale units

Scan function off

Scan function on

8.4.2

S

Scan Rate

The next function in the main menu is the scan rate. The scan rate can be set
from 0.001 to 5.0 °C/min. The maximum scan rate however is actually limited
by the natural heating or cooling rate of the instrument. This is less than

2.5°C/min, especially when cooling. The scan rate function appears in the main

menu after the scan control function. The scan rate units are in degrees per
minute, degrees C or F depending on the selected units.

Sr=0.010

Press “UP” or “DOWN” to change the scan rate.

Sr=2.0

Press “SET” to accept the new scan rate and continue.

Accept scan setting

Scan rate in °C/min

New scan rate

39

8 Controller Operation

8.5

8.6

Temperature Scale Units

The temperature scale units of the controller may be set by the user to degrees
Celsius (°C) or Fahrenheit (°F). The units are used in displaying the bath tem­perature, set-point, vernier, proportional band, and cutout set-point.

The temperature scale units selection is accessed after the vernier adjustment
function by pressing “SET”. From the temperature display function access the
units selection by pressing “SET” 4 times.

Un= C

Press “UP” or “DOWN” to change the units.

U

Un= F

Press “SET” to accept the new selection and resume displaying the bath
temperature

S

Change units

.

Set the new units and resume temperature display

Scale units currently selected

New units selected

Ramp and Soak Program

The ramp and soak program feature allows the user to program a number of
set-points and have the instrument automatically cycle between the tempera­tures, holding at each for a length of time. The user can select one of four dif­ferent cycle functions.

40

The program parameter menu is accessed by pressing “SET” and then “UP”.

|

100.00 C

S+U

ProG

Press “SET” to enter the program menu

S

8.6.1

Number of Program Set-points

The first parameter in the program menu is the number of set-points to cycle
through. Up to 8 set-points can be used in a ramp and soak program. These

Enter program menu

Well temperature

Access program menu

Program menu

8 Controller Operation

set-points are independent from the programmable set-points described in Sec­tion 8.3.1, Programmable Set-points.

Pn=8

Use the “UP” or “DOWN” buttons to change the number from 2 to 8.

Pn=3

Press “SET” to continue. Press “EXIT” to ignore any changes and to continue.

Number of program set-points

New number of program set-points

8.6.2

S

Set-points

The next parameters are the program set-points.

1 50.0

Use the “UP” or “DOWN” buttons to select any of the set-points.

3 30.0

Press “SET” to be able to change the set-point.

C 30.00

Use “UP” and “DOWN” to change the set-point value.

C 40.00

Press “SET” to save the ne

The other set-points can also be set in the same manner. Once the set-points are
programmed as desired press “EXIT” to continue.

Save new setting

First set-point

Third set-point

Set-point value

New set-point value

w set-po

int value.

8.6.3

E

Program Soak Time

The next parameter in the program menu is the soak time. This is the time, in
minutes, that each program set-point is maintained after settling before pro­ceeding to the next set-point. The duration is counted from the time the temper­ature reaches the set-point.

Continue to next menu function

Pt=15

Soak time in minutes

41

8 Controller Operation

Use the “UP” or “DOWN” buttons to change the time.

Pt=5

Press “SET” to continue.

New soak time

S

8.6.4

Program Function Mode

The next parameter is the program function or cycle mode. There are four pos­sible modes which determine whether the program scans up (from set-point 1
to n) only or both up and down (from set-point n to 1), and also whether the
program stops after one cycle or repeats the cycle indefinitely. Table 3 below
shows the action of each of the four program mode settings.

1

2

3

4

Save new setting

Pf=1

up-stop

up-down-stop

up-repeat

up-down-repeat

Program mode

Use the “UP” or “DOWN” buttons to change the mode.

Pf=4

New mode

Press “SET” to continue.

S

8.6.5

Program Control

The final parameter in the program menu is the control parameter. Three op­tions are available for controlling the ramp and soak program. The options are
to start the program from the beginning, (GO), continue the program from
where it was when it was stopped (

Pr=OFF

Enter program menu

Program presently off

Cont

), or stop the program (

OFF).

Use the “UP” or “DOWN” buttons to change the status.

42

8 Controller Operation

Pr=Cont

Press “SET” to activate the new program control command and return to the
temperature display.

Start cycle from beginning

Activate new command

8.7

S

Secondary Menu

Functions, which are used less often, are accessed within the secondary menu.
The secondary menu is accessed by pressing “SET” and “EXIT” simulta­neously and then releasing. The first function in the secondary menu is the
heater power display.

8.8

Heater Power

The temperature controller controls the temperature of the bath by pulsing the
heater on and off. The total power being applied to the heater is determined by
the duty cycle or the ratio of heater on time to the pulse cycle time. This value
may be estimated by watching the red/green control indicator light or read di­rectly from the digital display. By knowing the amount of heating the user can
tell if the bath is heating up to the set-point, cooling down, or controlling at a
constant temperature. Monitoring the percent heater power lets the user know
the stability of the bath temperature. With good control stability the percent
heating power should not fluctuate more than ±1% within one minute.

The heater power display is accessed in the secondary menu. Press “SET” and
“EXIT” simultaneously and release. The heater power is displayed as a percent­age of full power.

S+E

12 Pct

To exit out of the secondary menu press “EXIT”. To continue on to the propor­tional band setting function press “SET”.

E

8.9

Proportional Band

In a proportional controller such as this the heater output power is proportional
to the bath temperature over a limited range of temperatures around the
set-point. This range of temperature is called the proportional band. At the bot­tom of the proportional band the heater output is 100%. At the top of the pro-

Access heater power in secondary menu

Heater power in percent

Return to temperature display

43

8 Controller Operation

portional band the heater output is 0. Thus as the bath temperature rises the
heater power is reduced, which consequently tends to lower the temperature
back down. In this way the temperature is maintained at a fairly constant
temperature.

The temperature stability of the bath depends on the width of the proportional
band (see Figure 6). If the band is too wide, the bath temperature deviates ex­cessively from the set-point due to varying external conditions. This is because
the power output changes very little with temperature and the controller cannot
respond very well to changing conditions or noise in the system. If the propor­tional band is too narrow, the bath temperature may swing back and forth be­cause the controller overreacts to temperature variations. For best control
stability the proportional band must be set for the optimum width.

Proportional Band too Narrow Proportional Band too Wide

Figure 6

Bath Temperature Fluctuation At Various Proportional Band Settings

Optimum Proportional Band

The optimum proportional band width depends on several factors among which
are fluid volume, fluid characteristics (viscosity, specific heat, thermal conduc­tivity), heater power setting, operating temperature, and stirring. Thus the pro­portional band width may require adjustment for best bath stability when any of
these conditions change. Of these, the most significant factors affecting the op­timum proportional band width are heater power setting and fluid viscosity.
The proportional band should be wider when the higher power setting is used
so that the change in output power per change in temperature remains the same.
The proportional band should also be wider when the fluid viscosity is higher
because of the increased response time.

The proportional band width is easily adjusted from the bath front panel. The
width may be set to discrete values in degrees C or F depending on the selected
units. The optimum proportional band width setting may be determined by
monitoring the stability with a high resolution thermometer or with the control-

44

8 Controller Operation

ler percent output power display. Narrow the proportional band width to the
point at which the bath temperature begins to oscillate and then increase the
band width from this point to 3 or 4 times wider. Table 4 lists typical propor­tional band settings for optimum performance with a variety of fluids at se­lected temperatures.

Table 4

Typical Proportional Band Settings for Various Fluids

Fluid Temperature

Water

Water

Eth-Gly 50%

Eth-Gly 50%

Eth-Gly 50%

Oil 200, 10cs

Oil 200, 10cs

Oil 200, 10cs

Oil 710

The proportional band adjustment may be accessed within the secondary menu.
Press “SET” and “EXIT” to enter the secondary menu and show the heater
power. Then press “SET” to access the proportional band.

S+E

12 Pct

S

Access proportional band

30°C 0.31°C

60°C 0.31°C

35°C 0.31°C

60°C 0.31°C

100°C 0.4°C

35°C 0.6°C

60°C 0.6°C

100°C 0.6°C

200°C 0.4°C

Access heater power in secondary menu

Heater power in percent

Proportional Band

Stability

±0.003°C

±0.003°C

±0.005°C

±0.005°C

±0.010°C

±0.004°C

±0.004°C

±0.004°C

±0.008°C

Pb=0.101C

To change the proportional band press “UP” or “DOWN”.

D

Pb=0.060C

To accept the new setting and access the cutout set-point press “SET”. Pressing
“EXIT” will exi
proportional band value.

Proportional band setting

Decrement display

New proportional band setting

t the secondary menu ignoring any changes just made to the

45

8 Controller Operation

8.10

S

Cutout

As a protection against software or hardware fault, shorted heater triac, or user
error, the bath is equipped with an adjustable heater cutout device that shuts off
power to the heater if the bath temperature exceeds a set value. This protects
the heater and bath materials from excessive temperatures and, most impor­tantly, protects the bath fluids from being heated beyond the safe operating
temperature preventing hazardous vaporization, breakdown, or ignition of the
liquid. The cutout temperature is programmable by the operator from the front
panel of the controller. It must always be set below the upper temperature limit
of the fluid and no more than 10 degrees above the upper temperature limit of
the bath.

If the cutout is activated because of excessive bath temperature, power to the
heater is shut off and the bath cools. The bath cools until it reaches a few de­grees below the cutout set-point temperature. At this point the action of the cut­out is determined by the setting of the cutout mode parameter.

The cutout has two selectable modes — automatic reset or manual reset. If the
mode is set to automatic, the cutout automatically resets itself when the bath
temperature falls below the reset temperature allowing the bath to heat up
again. If the mode is set to manual, the heater remains disabled until the user
manually resets the cutout.

Accept the new proportional band s etting

The cutout set-point may be accessed within the secondary menu. Press “SET”
and “EXIT” to enter the secondary menu and show the heater power. Then
press “SET” twice to access the cutout set-point.

+

S

E

12 Pct

S

Pb=0.101C

S

CO= 110C

To change the cutout set-point press “UP” or “DOWN”.

D

46

Access heater power in secondary menu

Heater power in percent

Access proportional band

Proportional band setting

Access cutout set-point

Cutout set-point

Decrement display

8 Controller Operation

CO= 75C

To accept the new cutout set-point press “SET”.

New cutout set-point

8.11

8.12

S

The next function is the configuration menu. Press “EXIT” to resume display­ing the bath temperature.

Controller Configuration

The controller has a number of configuration and operating options and calibra­tion parameters, which are programmable via the front panel. These are ac­cessed from the secondary menu after the cutout set-point function by pressing
“SET.” There are 5 sets of configuration parameters - probe parameters, operat­ing parameters, serial interface parameters, and controller calibration parame­ters. The menus are selected using the “UP” and “DOWN” keys and then
pressing “SET”. Pressing “EXIT” in any secondary menu exits and returns to
displaying the temperature (see Figure 5 on page 36, Controller Operation
Flowchart).

Probe Parameters

The probe menu is indicated by,

PrObE

Press “SET” to enter the menu. The probe parameters menu contains the pa­rameters, R0 and ALPHA, which characterize the resistance-temperature rela­tionship of the platinum control probe. These parameters may be adjusted to
improve the accuracy of the bath. This procedure is explained in detail in Sec­tion 10, Calibration Procedure.

Accept cutout set-point

Probe parameters menu

8.12.1

The probe parameters are accessed by pressing “SET” after the name of the pa­rameter is displayed. The value of the parameter may be changed using the
“UP” and “DOWN” buttons. After the desired value is reached press “SET” to
set the parameter to the new value. Press “EXIT” to skip the parameter ignoring
any changes that have been made.

R0

This probe parameter refers to the resistance of the control probe at 0°C.
Normally this is set for 100.000 ohms.

47

8 Controller Operation

8.12.2

8.13

8.13.1

ALPHA

This probe parameter refers to the average sensitivity of the probe between 0
and 100°C. Normally this is set for 0.00385°C

Operating Parameters

The operating parameters menu is accessed by pressing “UP” when the probe
menu is displayed.

The operating parameters menu is indicated by,

Press “UP” to enter the menu. The operating parameters menu contains the cut­out

Cutout Reset Mode

The cutout reset mode determines whether the cutout resets automatically when
the bath temperature drops to a safe value or must be manually reset by the
operator.

The parameter is indicated by,

–1

.

PAr

mode parameter, cooling mode, and hot gas bypass mode.

reset

CtorSt

Operating parameters menu

Cutout reset mode parameter

48

Press “SET” to access the parameter setting. Normally
tomatic mode.

Cto=Auto

To change to manual reset mode press “UP” and then “SET”.

Cto=rSt

8.13.2

Cooling Mode

The cooling mode determines whether refrigeration is in Auto mode, On, or
Off. Normally the cooling mode is set to Auto mode. In the Auto mode, the re­frigeration is ‘On’ below approximately 60°C. Note: If the fluid is cooling
from above 60°C, the refrigeration turns on at approximately 59°C. If the fluid
is heating from below 60°C, the refrigeration shuts off at 60°C. There may be
times when Auto mode is undesirable. In that case, the refrigeration may be set
to On or Off. When the refrigeration is set to On or Off, the refrigeration is on
or off for all temperatures.

Cutout set for automatic reset

Cutout set for manual reset

the cutout is set for au-

8 Controller Operation

Caution: The refrigeration may be damaged or the lifetime shortened if

used above 60°C for more than one hour.

The parameter is indicated by,

CooL

Press “SET” to access the parameter setting.

Cooling mode parameter

8.13.3

C=Auto

To change to On or Off mode, press “DOWN” until the desired mode appears
and the

C=On

C=Off

Individual steps may be skipped by pressing “EXIT”

Hot Gas Bypass Mode

The hot gas bypass (HGb) system is a method of reducing cooling or refrigera­tion capacity. It is normally used above approximately 0°C. Reducing cooling
capacity helps improve temperature stability in the bath and reduces energy
consumption. The HGb system is normally in the automatic mode which
switches on (reducing capacity) when at set-points above 0°C. When the bath is
scanning to lower temperatures (greater than 2°C below the starting tempera­ture) the HGb turns off for full cooling capacity for all temperatures below the
maximum refrigeration limit even above 0°C.

There are three HGb modes; Auto, On, or Off. Normally HGb mode is set to
Auto mode. If for some reason the automatic mode is undesirable, the HGb
mode can be set to always On or Off.

press “SET”.

n

Cooling mode set for automatic

Cooling mode set to on

Cooling mode set to off

The parameter is indicated by,

Hgb

Press “SET” to access the parameter setting.

Hgb=Auto

To change to On or Off mode, press “DOWN” until the desired mode appears

n

and the

press “SET”.

HGb mode parameter

HGb mode set for automatic

49

8 Controller Operation

8.14

Hgb=On

Hgb=Off

Serial Interface Parameters

The serial interface menu is accessed by pressing “UP” from the operating pa­rameters menu.

HGb mode set to on

HGb mode set to off

The serial RS-232 interface parameters menu is indicated by,

SErIAL

The serial interface parameters menu contains parameters which determine the
operation of the serial interface. The parameters in the menu are—baud rate,
sample period, duplex mode, and linefeed.

Serial RS-232 interface parameters menu

8.14.1

Baud Rate

The baud rate is the first parameter in the menu. The baud rate setting deter­mines the serial communications transmission rate.

The baud rate parameter is indicated by,

Press “SET” to choose to set the baud rate. The current baud rate value will
then be displayed.

The baud rate of the bath serial communications may be programmed to 300,
600, 1200, 2400, or 9600 baud. Use “UP” or “DOWN” to change the baud rate
value.

Press “SET” to set the baud rate to the new value or “EXIT” to abort the opera­tion and skip to the next parameter in the menu.

bAUd

9600 b

2400 b

Serial baud rate parameter

Current baud rate

New baud rate

8.14.2

Sample Period

The sample period is the next parameter in the serial interface parameter menu.
The sample period is the time period in seconds between temperature measure­ments transmitted from the serial interface. If the sample rate is set to 5, the
bath transmits the current measurement over the serial interface approximately

50

8 Controller Operation

every five seconds. The automatic sampling is disabled with a sample period of

0. The sample period is indicated by,

8.14.3

SAnPLE

Press “SET” to choose to set the sample period. The current sample period
value

will be displayed.

SA= 1

Adjust the value with “UP” or “DOWN” and then
rate to the displayed value.

SA= 60

Duplex Mode

The next parameter is the duplex mode. The duplex mode may be set to full du­plex or half duplex. With full duplex any commands received by the bath via
the serial interface are immediately echoed or transmitted back to the device of
origin. With half duplex the commands are executed but not echoed. The du­plex mode parameter is indicated by,

dUPL

Press “SET” to access the mode setting.

dUP=FULL

Serial sample period parameter

Current sample period (seconds)

New sample period

use “SET” to set the sample

Serial duplex mode parameter

Current duplex mode setting

8.14.4

The mode may be changed using “UP” or “DOWN” and pressing “SET”.

dUP=HALF

Linefeed

The final parameter in the serial interface menu is the linefeed mode. This pa­rameter enables (on) or disables (off) transmission of a linefeed character (LF,
ASCII 10) after transmission of any carriage-return. The linefeed parameter is
indicated by,

Press “SET” to access the linefeed parameter.

LF

LF= On

New duplex mode setting

Serial linefeed parameter

Current linefeed setting

51

8 Controller Operation

The mode may be changed using “UP” or “DOWN” and pressing “SET”.

8.15

8.15.1

LF= OFF

Calibration Parameters

The operator of the bath controller has access to a number of the bath calibra­tion constants namely CTO, C0, CG, H, L, and HGbt. These values are set at
the factory and must not be altered. The correct values are important to the ac­curacy and proper and safe operation of the bath. These parameters should not
be adjusted. In the event the controller’s memory fails, the user may restore
these values to the factory settings. A list of these constants and their settings
are supplied to the user on the Report of Test with the manual.

Caution: DO

from the factory set values. The correct setting of these parameters is im­portant to the safety and proper operation of the bath.

The calibration parameters menu is indicated by,

CAL

Press “SET” five times to enter the menu.

CTO

New linefeed setting

NO

T change the values of the bath calibration constants

Calibration parameters menu

52

Parameter CTO sets the calibration of the over-temperature cutout. This is not
adjustable by software but is adjusted with an internal potentiometer. This pa­rameter is set at the factory.

8.15.2

8.15.3

CO and CG

These parameters calibrate the accuracy of the bath set-point. These are pro­grammed at the factory when the bath is calibrated. Do not alter the value of
these parameters. If the user desires to calibrate the bath for improved accuracy,
calibrate R0 and ALPHA according to the procedure given in Section 10, Cali­bration Procedure.

H and L

These parameters set the upper and lower set-point limits of the bath.

Note: A high limit (H) setting below the flash point of the fluid in the bath is
highly recommended.

8 Controller Operation

8.15.4

HGbt

This parameter is the temperature where the hot gas bypass activates. This pa­rameter is factory set. To insure the bath's best performance without damaging
its compressor, DO NOT alter the value of this parameter.

53

9Digital Communication Interface

9 Digital Communication Interface

The CTR –40 bath is capable of communicating with and being controlled by
other equipment through the digital interface.

With a digital interface the bath may be connected to a computer or other
equipment. This allows the user to set the bath temperature, monitor the tem­perature, and access any of the other controller functions, all using remote com­munications equipment. In addition the cooling may be controlled using the
interface. To control the cooling with the interface the cooling power switch
must be ON.

9.1

Serial Communications

The RS-232 serial interface allows serial digital communications over fairly
long distances (15.24 meters). With the serial interface the user may access any
of the functions, parameters and settings discussed in Section 8, Controller Op­eration with the exception of the baud rate setting. The serial interface operates
with eight data bits, one stop bit, and no parity.

55

9 Digital Communication Interface

9.1.1

9.1.2

Wiring

The serial communications cable
attaches to the bath through the
DB-9 connector on the back of the

RS-232 Cable Wiring for
IBM PC and Compatibles

instrument. Figure 7 shows the
pin-out of this connector and the
suggested cable wiring. To elimi­nate noise, the serial cable should
be shielded with low resistance be­tween the connector (DB-9) and
the shield.

Setup

Instrument
Connector
(DB 9-Pin)

1 NC
2 RxD
3 TxD
4 NC
5 GND
6 NC
7

RTS

8

CTS

9 NC

Computer (DTE)

Connector
(DB 9-Pin)

1

DCD
2 RxD
3 TxD
4

DTR
5 GND
6

DSR
7

RTS
8

CTS
9 NC

Before operation the serial inter­face of the bath must first be set up
by programming the baud rate and
other configuration parameters.
These parameters are programmed
within the serial interface menu.

To enter the serial parameter pro­gramming menu, press “EXIT”
while holding down “SET”, then
release both buttons to enter the
secondary menu. Press “SET” re-

Connector
(DB 9-Pin)

1 NC
2 RxD
3 TxD
4 NC
5 GND
6 NC
7

RTS

8

CTS

9 NC

Figure 7

Serial Communications Cable Wiring

Computer (DTE)

Connector
(DB 25-Pin)

2

TxD

3

RxD

4

RTS

5

CTS

6

DSR

7

GND

8

DCD
20 DTR

Instrument

peatedly until the display reads
“ProbE”. This is the menu selec-

tion. Press “UP” repeatedly until the serial interface menu is indicated with
“SErIAL”. Finally press “SET” to enter the serial parameter menu. In the serial
interface parameters menu are the baud rate, the sample rate, the duplex mode,
and the linefeed parameter.

56

9.1.2.1

Baud Rate

The baud rate is the first parameter in the menu. The display prompts with the
baud rate parameter by showing “BAUd”. Press “SET” to choose to set the
baud rate. The current baud rate value is displayed. The baud rate of the bath
may be programmed to 300, 600, 1200, 2400, or 9600 baud. The baud rate is
pre-programmed to 9600 baud. Use “UP” or “DOWN” to change the baud rate
value. Press “SET” to set the baud to the new value or “EXIT” to abort the op­eration and skip to the next parameter in the menu.

9Digital Communication Interface

9.1.2.2

9.1.2.3

9.1.2.4

Sample Period

The sample period is the next parameter in the menu and prompted with
“SAMPLE”. The sample period is the time period, in seconds, between
temperature measurements transmitted from the serial interface. If the sample
period is set to 5, the bath transmits the current measurement over the serial
interface approximately every five seconds. The automatic sampling is
disabled with a sample period of 0. Press “SET” to choose to set the sample
period. Adjust the period with “UP” or “DOWN”. Press “SET” to set the
sample period to the new value or “EXIT” to abort and skip to the next
parameter.

Duplex Mode

The next parameter is the duplex mode indicated with “dUPL”. The duplex
mode may be set to half duplex (“HALF”) or full duplex (“FULL”). With full
duplex any commands received by the bath via the serial interface are executed
and immediately echoed or transmitted back to the device of origin. With half
duplex the commands are executed but not echoed. The default setting is full
duplex. The mode may be changed using “UP” or “DOWN”. Press “SET” to
save the new setting or “EXIT” to abort and skip to the next parameter.

Linefeed

The final parameter in the serial interface menu is the linefeed mode. This pa­rameter enables (“On”) or disables (“OFF”) transmission of a linefeed charac­ter (LF, ASCII 10) after transmission of any carriage-return. The default setting
is with linefeed on. The mode may be changed using “UP” or “DOWN”. Press
“SET” to set the sample period to the new value or “EXIT” to abort and skip to
the next parameter.

9.1.3 Serial Operation

Once the cable has been attached and the interface set up properly the control­ler will immediately begin transmitting temperature readings at the pro­grammed rate. The set-point and other commands may be sent to the bath via
the serial interface to set the bath and view or program the various parameters.
The interface commands are discussed in Section 9.2, Interface Commands.

9.2

Interface Commands

The various commands for accessing the bath controller functions via the digi­tal interfaces are listed in this section (see Table 5 starting on page 59). These
commands are used with the RS-232 serial interface. The commands are termi­nated with a carriage-return character. The interface makes no distinction be­tween upper and lower case letters, hence either may be used. Commands may
be abbreviated to the minimum number of letters, which determines a unique

57

9 Digital Communication Interface

command. A command may be used to either set a parameter or display a pa­rameter depending on whether or not a value is sent with the command follow­ing a “=” character. For example an “s” <cr> returns the current set-point and
an “s=50.00" <cr> sets the set-point to 50.00 degrees.

In the list of commands, characters or data within brackets, “[” and “]”, are op­tional for the command. A slash, “/”, denotes alternate characters or data. Nu­meric data, denoted by “n”, may be entered in decimal or exponential notation.
Characters are shown in lower case although upper case may be used. Spaces
may be added within command strings and will simply be ignored. Backspace
(BS, ASCII 8) may be used to erase the previous character. A terminating CR is
implied with all commands.

9.3

Cooling Control

The CTR –40 bath has a fully automated refrigeration control system when the
cooling power switch on the front panel is activated. Under normal conditions,
the refrigeration is on at any temperature below approximately 60°C (see Sec­tion 7.6, Refrigeration). When the bath is controlling at temperatures between
0°C and 60°C, the refrigeration is in the hot gas bypass or reduced cooling
mode. Below 0°C the refrigeration is in the high cooling mode, the hot gas by­pass is turned off automatically. When the bath is cooling from one temperature
to another below 60°C, cooling is at maximum until the bath is within 1 degree
C of the set-point. These conditions are the default conditions but may be al­tered in the following ways.

• The cooling (refrigeration) may be set to operate in the auto, on, or off

modes. See Section 8.13.2, Cooling Mode.

• The hot gas bypass or reduced cooling mode may also be set to on, off, or

auto.

The “auto” modes allow the bath to operate automatically in the manner de­scribed above. The cooling “on” function eliminates this auto feature and the
refrigeration is on at all times unless the front panel switch is turned off or until
some other menu selection is made. The hot gas bypass mode selection works
the same way. The “auto” function is the default and active until off or on is se­lected. “On” means it is always on with no automatic selection and “off” is al­ways off (or cooling always on maximum). It may desirable for different
reasons to eliminate the automatic functioning; therefore, these selections are
made available either through the front panel or through the digital communica­tions interface.

58

Table 5

}

}

p

Interface Command Summary

9Digital Communication Interface

Command Description
Display Temperature

Read current set-point

Set current set-point to

Read vernier

Set vernier to

Read scan function

Turn scan function on

Turn scan function off

Read scan rate

Set scan rate to n degrees per
minute

Read temperature

Read temperature units

Set temperature units:

Set temperature units to Celsius

Set temperature units to
Fahrenheit

Ramp and Soak Menu

Read number of programmable
set-points

Set number of programmable
set-points to n

Read programmable set-point

n

number

Set programmable set-point num­ber n to n

Read program set-point soak time

Set program set-point soak time to

n minutes

Read program control mode

Set program control mode:

Start program

n

n

Command
Format

s[etpoint]

s[etpoint]=n

v[ernier]

v[ernier]=n v=.00001

sc[an]

sc[an]=on

sc[an]=of[f]

sr[ate]

sr[ate]=

t[emperature] t t: 9999.99 {C or t: 55.69 C

u[nits]

u[nits]=c/f

u[nits]=f

pn pn pn: 9 pn: 2

pn=

ps

psn=

pt pt

pt=

pc pc

pc=g[o]/s[top]/c[ont]

pc=g[o] pc=g

u[nits]=c

n

n

n

n

n

Command
Example

s

s=150

v v: 9.99999 v: 0.00000

sc

sc=on

sc=of

sr srat: 9.999 {C or srat: 0.010 C/ min

sr=5

u

u=c

u=f

pn=4

ps3

s3=50

pt=5

Returned

set: 9999.99 {C set: 150.0 0 C

orF

scan: {ON or
OFF}

F}/min

F

u: x

ps

n

: 9999.99 {C

or F}

ti: 999

prog: {OFF or prog: OFF

ON}

Returned
Example

scan: ON

u: c

ps1: 50.00 C

ti: 5

Acceptable Values

Instrument Range

Depends on Configuration

0.001 to 5.000°C/min

0.002 to 9.000°F/min

C or F

2 to 8

1 to 8, Instrument Range

0 to 500

GO or STOP or CONT

59

9 Digital Communication Interface

Interface Command Summary Continued

Command Description

Stop program

Continue program
Read program function

Set program function to

Secondary Menu

Read proportional band setting

Set proportional band to

Read cutout setting

Set cutout setting:

Set cutout to n degrees

Reset cutout now
Read heater power

(duty cycle)

Probe Menu

Read R0 calibration parameter

Set R0 calibration parameter to

Read ALPHA calibration parameter al[pha] al

Set ALPHA calibration parameter to al[pha]=n

n

Operating Parameters Menu

Read cutout mode

Set cutout mode:

Set cutout to be reset manually-

Set cutout to be reset

automatically

n

n

Command
Format

pc=s[top]

pc=c[ont]

pf

pf=

pr[op-band] pr

pr[op-band]=n

c[utout]

c[utout]=n/r[eset]

c[utout]=n
c[utout]=r[eset]

po[wer]

r[0]

n

cm[ode]

cm[ode]=r[eset]/a[uto]

cm[ode]=r[eset]

cm[ode]=a[uto]

n

r[0]=n

Command
Example

pc=s

pc=c

pf

pf=2

pr=0.326

c

c=160
c=r

po

r

r=100.324

al=0.0038433

cm

cm=r

cm=a

Returned

Returned

pf: 9 pf: 3

pr: 999.999 pr: 0.326

cu: 9999
{x},{xxx}

po: 9999 po: 1

r0: 999.999 r0: 100.578

al: 9.9999999 al: 0.0038573

cm: {xxxx}

Example

cu: 160 C, in

cm: AUTO

Acceptable Values

1 to 4

Depends on Configuration

Temperature Range

98.0 to 104.999

.00370 to .0039999

RESET or AUTO

Read serial sample setting

Set serial sampling setting to
seconds

Set serial duplex mode:

Set serial duplex mode to full

Set serial duplex mode to half

Set serial linefeed mode:

Set serial linefeed mode to on

Set serial linefeed mode to off

60

sa[mple]

n

sa[mple]=n

du[plex]=f[ull]/h[alf]

du[plex]=f[ull]

du[plex]=h[alf]

lf[eed]=on/of[f]

lf[eed]=on

lf[eed]=of[f]

sa sa: 9999

sa=0

du=f

du=h

lf=on

lf=of

sa: 1

0 to 4000

FULL or HALF

ON or OFF

9Digital Communication Interface

Interface Command Summary Continued

Command Description
Calibration Menu

Read C0 calibration parameter

Set C0 calibration parameter to

Read CG calibration parameter

Set CG calibration parameter to

Read Cool mode

Set Cool mode:

Set Cool mode to Off

Set Cool mode to On

Set Cool mode to Auto

Read HGb mode

Set HGb mode:

Set HGb mode to Off

Set HGb mode to On

Set HGb mode to Auto
Read low set-point limit value

Set low set-point limit to

Read high set-point limit value

Set high set-point limit to

Miscellaneous (not on menus)

Read firmware version number

Read structure of all commands

Legend:

Note:

n

n

n

Command
Format

*c0 *c0

n

*c0=n *c0=0

*cg *cg

*cg=n

co[ol]

co[ol]=of[f]/on/au[to]

co[ol]=of[f]

co[ol]=on

co[ol]=au[to]

hg[b]

hg[b]=of[f]/on/au[to]

hg[b]=of[f]

hg[b]=on

hg[b]=au[to]
*tl[ow]

*tl[ow]=n

*th[igh] *th

*th[igh]=n *th=150

Command
Example

*cg=406.25

co

co=of

co=on

co=au

hg

hg=of

hg=on

hg=au
*tl

*tl=–40

Returned

c0: 9.9999 c0: 0.0002

cg: 999.999 cg: 406.25

co:xxx

hgb:xxx

tl: 999

th: 999 th: 150

Returned
Example

co: Auto

hgb: Auto

tl: –40

Acceptable Values

Unlimited

Unlimited

On, Off, Auto

On, Off, Auto

–60 to 20

–150 to 30

*ver[sion]

h[elp] h

[] Optional Command data

{} Returns either information

n Numeric data supplied by user

9 Numeric data returned to user

x Character data returne d to user
When DUPLEX is set to FULL and a command is sent to READ, the command is returned followed by a car-

riage return and linefeed. Then the value is returned as indicated in the RETURNED column.

*ver ver.9999,9.99

list of commands

ver.7340,1.00

61

10 Calibration Procedure

10

10.1

Calibration Procedure

In some instances the user may want to calibrate the bath to improve the tem­perature set-point accuracy. Calibration is done by adjusting the controller
probe calibration constants R0 and ALPHA so that the temperature of the bath
as measured with a standard thermometer agrees more closely with the bath
set-point. The thermometer used must be able to measure the bath fluid temper­ature with higher accuracy than the desired accuracy of the bath. By using a
good thermometer and carefully following procedure the bath can be calibrated
to an accuracy of better than 0.02°C over a range of 100 degrees.

Calibration Points

In calibrating the bath R0 and ALPHA are adjusted to minimize the set-point
error at each of two different bath temperatures. Any two reasonably separated
bath temperatures may be used for the calibration however best results will be
obtained when using bath temperatures which are just within the most useful
operating range of the bath. The further apart the calibration temperatures, the
greater the calibrated temperature range and the calibration error. If, for in­stance, 0°C and 100°C are chosen as the calibration temperatures, the bath may
achieve an accuracy of ±0.03°C over the range –10 to 110°C. Choosing 30°C
and 70°C may allow the bath to have a better accuracy of ±0.01°C over the
range 25 to 75°C, but, outside that range the accuracy may be only ±0.05°C.

10.2

10.3

Measuring the Set-point Error

The first step in the calibration procedure is to measure the temperature errors
(including sign) at the two calibration temperatures. First set the bath to the
lower set-point, t
to stabilize at that temperature. Check the bath stability with the thermometer.
When both the bath and the thermometer have stabilized, measure the actual
bath temperature and compute the temperature error, err
perature minus the set-point temperature). For example, set the bath to 0°C.
The bath reaches a measured temperature of –0.3°C giving an error of –0.3°C.

Next, set the bath for the upper set-point, t
bath temperature and compute the error err
100°C, the thermometer measures 100.1°C giving an error of +0.1°C.

. Wait for the bath to reach the set-point and allow 15 minutes

L

Computing R0 and ALPHA

Before computing the new values for R0 and ALPHA the current values must
be known. The values may be found by either accessing the probe calibration
menu from the controller panel or by inquiring through the digital interface.
The user should keep a record of these values in case they may need to be re-

(the actual bath tem-

L

, and after stabilizing, measure the

H

. For example, set the bath to

H

63

R

10 Calibration Procedure

R0 = 100.000

ALPHA = 0.0038500

t

= 30.00°C

L

measured t = 29.843°C

t

= 80.00°C

H

measured t = 79.914°C

Compute errors,

err

= 29.843 - 30.00°C = -0.157°C

L

err

= 79.914 - 80.00°C = -0.086°C

H

Compute R0′,

ϒ

(−0.086) × 30.0 − (−0.157) ×

80.0

′ =

′

0

≤

Compute ALPHA′,

ϒ

ALPHA

Figure 8

′ =

′

≤

Calibration Example

⁄

0.00385 + 1 ∞100.000 = 100.077

80.0 − 30.0

(1 + 0.00385 × 80.0 )( −0.157) − (1 + 0.00385 × 30.0 )( −0.086 )

ƒ

80.0 − 30.0

stored in the future. The new values R0′ and ALPHA′ are computed by entering
the old values for R0 and ALPHA, the calibration temperature set-points t

, and the temperature errors errL and errH into the following equations,

t

H

R

′ =

0

≤

ALPHA

ϒ

err

−

err

H tL

′

t

ϒ

(1

′ = ′

L tH

− t

H

L

)

ALPHA t

+

ALPHA

H

≤

⁄

R

+

1

∞

ƒ

(1 )

err

− +

L

tH −

t

L

0

ALPHA t

⁄

+

1∞ 0.00385 = 0.0038416

ƒ

⁄

err

L

H

+

1∞ ALPHA

ƒ

L

and

64

10 Calibration Procedure

If R0 and ALPHA were previously set for 100.000 and 0.0038500 respectively
and the data for t

R0′ and ALPHA′ would be computed as 110.116 and 0.0038302 respectively.
Program the new values R0 and ALPHA into the controller. Check the calibra-
tion by setting the temperature to t
desired, the calibration procedure may be repeated again to further improve the
accuracy.

, tH, errL, and errH were as given above then the new values

L

and tH and measuring the errors again. If

L

10.4

Calibration Example

The bath is to be used between 25°C and 75°C and it is desired to calibrate the
bath as accurately as possible for operation within this range. The current val­ues for R0 and ALPHA are 100.000 and 0.0038500 respectively. The calibra­tion points are chosen to be 30.00 and 80.00°C. The measured bath
temperatures are 29.843 and 79.914°C respectively. Refer to Figure 8 for ap­plying equations to the example data and computing the new probe constants.

65

11 Maintenance

11

Maintenance

• The calibration instrument has been designed with the utmost care. Ease

of operation and simplicity of maintenance have been a central theme in
the product development. Therefore, with proper care the instrument
should require very little maintenance. Avoid operating the instrument in
dirty or dusty environments.

• If the outside of the bath becomes soiled, it may be wiped clean with a

damp cloth and mild detergent. Do not use harsh chemicals on the sur­face, which may damage the paint.

• Periodically check the fluid level in the bath to ensure that the level has

not dropped. A drop in the fluid level affects the stability of the bath.
Changes in fluid level are dependent upon several factors specific to the
conditions in which the equipment is used. A schedule cannot be outlined
to meet each set of conditions. Therefore, the bath should be checked
weekly and adjustments made as required.

• Heat transfer medium lifetime is dependent upon the type of medium and

the conditions of use. The fluid should be checked at least every month
for the first year and regularly thereafter. This fluid check provides a
baseline for knowledge of bath operation with clean, usable fluid. Once
some fluids have become compromised, the break down can occur rap­idly. Particular attention should be paid to the viscosity of the fluid. A sig­nificant change in the viscosity can indicate that the fluid is contaminated,
being used outside of its temperature limits, contains ice particles, or is
close to a chemical breakdown. Once data has been gathered, a specific
maintenance schedule can be outlined for the instrument. Refer to Section
7, General Operation, for more information about the different types of
fluids used in calibration baths.

• Depending on the cleanliness of the environment, the internal parts (parts

behind the front cover only) of the cold bath should be cleaned and/or
checked at least every six months for dust and dirt. Particular attention
should be paid to the condensing coil fins. The fins should be vacuumed
or brushed free of dust and dirt on a regular basis. Dust and dirt inhibit the
operation of the condensing coil and thus compromise the performance
and lifetime of the cooling system.

To clean or check the internal parts, remove the four screws on the fornt
panel display. Remove the two screws under the front panel on the left
and right sides. Pull the front panel up and out to remove.

• If a hazardous material is spilt on or inside the equipment, the user is re-

sponsible for taking the appropriate decontamination steps as outlined by
the national safety council with respect to the material. MSDS sheets ap-

66

11 Maintenance

plicable to all fluids used in the baths should be kept in close proximity to
the instrument.

• If the mains supply cord becomes damaged, replace it with a cord of the

appropriate gauge wire for the current of the bath. If there are any ques­tions, call Amphenol Advanced Sensors Customer Service for mo

re

information.

• Before using any cleaning or decontamination method except those rec-

ommended by Hart, users should check with Amphenol Advanced
Sensors Customer Service to be sure that the proposed method will not
damage the equipment.

• If the instrument is used in a manner not in accordance with the equip-

ment design, the operation of the bath may be impaired or safety hazards
may arise.

• The over-temperature cutout should be checked every 6 months to see that

it is working properly. In order to check the user selected cutout,

follow
the controller directions (Section 8.2, Reset Cutout) for setting the cutout.
Both the manual and the auto reset option of the cutout should be
checked. Set the bath temperature higher than the cutout. Check to see if
the display flashes cutout and if the temperature is decreasing. Note:
When checking the over-temperature cutout, be sure that the temperature
limits of the bath fluid are not exceeded. Exceeding the temperature limits
of the bath fluid could cause harm to the operator, lab, and instrument.

67

12 Troubleshooting

12

12.1

Troubleshooting

This section contains information on troubleshooting, CE Comments, and a
wiring diagram. This information pertains to a number of bath models and cer­tain specifics may not pertain to your model.

Troubleshooting

In the event that the instrument appears to function abnormally, this section
may help to find and solve the problem. Several possible problem conditions
are described along with likely causes and solutions. If a problem arises, please
read this section carefully and attempt to understand and solve the problem. If
the probe seems faulty or the problem cannot otherwise be solved, contact
Amphenol Advanced Sensors Customer Service for assistance. Be sure to have
the instrument model number, serial number, voltage, and problem description
available.

The heater indicator LED stays red
but the temperature does not
increase

If the display does not show “
temperature, and the controller otherwise appears to operate normally,
the problem may be insufficient heating, no heating at all, or too much
cooling.

•

The heater power setting being too low, especially at higher operating
temperature

•

One or more burned out heaters or blown heater fuses may also cause
this problem. If the heaters seem to be burned out, c ontact Amphenol
Advanced Sensors Customer Service for assistance.

Cut-out

” nor displays an incorrect bath

68

12 Troubleshooting

Problem

The controller display flashes “Cut-

”

and the heater does

out

operate

The display flashes “cutout” and an
incorrect process temperature

not

Causes and Solutions

The display flashs “
temperature.

If the process temperature displayed seems grossly in error, consult the

•

following problem:

process temperature’.

•

Normally, the cutout disconnects power to the heater when the bath
temperature exceeds the cutout set-point causing the temperature to
drop back down to a safe value. If the cutout mode is set to “AUTO”, the
heater switches back on when the temperature drops. If the mode is set
to “RESET”, the heater only comes on again when the temperature is re­duced and the cutout is manually reset by the oper ator, see Section
Cutout. Check that the cutout set-point is adjusted to 10 or 20°C above
the maximum bath operating temperature and that the cutout mode is
set as desired.

•

If the cutout activates when the bath tempe rature is well below the cut­out set-point or the cutout does not reset when the bath temperat ure
drops and it is manually reset, then the cutout circuitry or the cutout
thermocouple sensor may be faulty or disconnected. Contact
Advanced Sensors

The problem may be that the controller’s voltmeter circuit is not function­ing properly.

•

A problem could exist with the memory back-up battery. If the battery
voltage is insuffic ient to maintain the mem ory, data may become s cram­bled causing problems. A nearby large static discharge may also affect
data in memory. Verify that the parameters on the Report of Test. are
accurate. Cycle the power off, disconnect the bath from AC, and then re­start the bath.

•

If the problem reoccurs, the battery should be replaced. Contact
Amphenol Advanced Sensors Customer Service for assistance.

•

If initializing the memory does not remedy the problem, there may be a
failed electronic component. Contact
Customer Service for assis

•

The controller may need to be reset. Perform the following Factory Re­set Sequence.

Factory Reset Sequence.

same time while powering up the instrument. The instrument display
shows '
the controller parameters and c alibration constants must be repro­grammed. The values can be found on the Report of Test that was
shipped with the instrument.

Cut-out

” alternately with the process

‘The display flashes “

Cus

tomer Service for assistance.

tance.

Hold the SET and EXIT buttons down at the

-init-

', the model number, and the firmware version. Each of

Cut-out

Amphenol Advanced Sensors

” and an incorrect

Amphenol

8.10,

69

12 Troubleshooting

The displayed process temperature
is in error and the controller re­mains in the cooling or the heating
state at any set-point value

The controller controls or attempts
to control at an inaccurate
temperature

Possible causes may be either a faulty control probe or erroneous data in
memory.

•

The probe may be disconnected, burned out, or shorte d. The probe is lo­cated inside the stirrer motor cover.

•

Check that the probe is connected properly. The probe may be checked
with an ohmmeter to see if it is open or shorted. The probe is a plati­num 4-wire Din 43760 type. The resistance should read 0.2 to 2.0 ohms
between pins 1 and 2 on the probe connector and 0.2 to 2.0 ohms be ­tween pins 3 and 4. It should read 100 to 300 ohms between pins 1 and
4 depending on the temperature. If the probe appears to be defective,
contact Amphenol Advanced Sensors Customer Service for assistance.

•

If the problem is not the probe, erroneous data in memory may be the
cause. Re-initialize the memory as discussed in the problem

flashes “cutout” and an incorrect process temperature’.

remains, the cause may be a defective electronic component, contact
Amphenol Advanced Sensors Customer Service for assistance.

The controller operates normally except when controlling at a specified
set-point. At this set-point, the temperature displayed does not agree
with the temperature measured by the user’s reference thermometer to
within the specified accuracy. This problem may be caused by an actual
difference in temperature betwee n the points where the control p robe
and thermometer probe measure temperature, by erro neous bath cali­bration parameters, or by a damaged c ontrol probe.

•

Check that the bath has an adequate amount of fluid in the tank and
that the stirrer is operating properly.

•

Check that the thermometer probe and co ntrol probe are both fully in­serted into the bath to minimize temperature gradient errors.

•

Check that the calibration parameters are all correct according to the
Report of Test. If not, re-program the constants. The memory backup
battery may be weak causing errors in data as described in the prob­lem:

‘The display flashes “cutout” and an incorrect process temperature’.

•

Check that the control probe has not been st ruck, bent, or damaged. If
the cause of the problem remains unknown, contact
Advanced Sensors

Customer Ser- vice for assistance.

‘The display

If the problem

Amphenol

The controller shows that the out­put power is steady but the proc ess
temperature is unstable

Possible causes are an improper proportional band setting or the fluid
being used.

•

•

If the bath temperature does not achieve the expected degree of stabil­ity when measured using a thermometer, try adjusting the proportional
band to a narrower width as discussed in Section 8.9, Proportional
Band.

Check to ensure the fluid has not deteriorated or is not too thick.

70

12 Troubleshooting

Problem

The controller alternately heats for
a while then cools

The controller erratically heats then
cools, control is unstable

The bath does not achieve low
temperatures

Causes and Solutions

The bath is not stable and the duty cycle is not constant.

•

The proportional band being too narrow typically causes this oscillation.
Increase the width of the proportional band until the temperature stabi ­lizes as discussed in Section 8.9, Proportional Band.

If both the bath temperature and output power do not vary periodically
but in a very erratic manner, the problem may be excess noise in the sys­tem. Noise due to the control sensor should be less than 0.001°C. How­ever, if the probe has been damaged or has developed an intermittent
short, erratic behavior may exist. The probe is located inside the stirrer
motor cover.

•

•

Too much heatin g or not enough cooling c an cause this proble m.

•

Check for a damaged probe or poor connection between the probe and
bath.

Intermittent shorts in the heater or controller electronic circuitry may
also be a possible cause. Contact Amphenol Advanced Sensors
Customer Service for assistance.

Check th at the control indicator glows green showing that the controller
is attempting to cool. The heaters may be disabled as a test by tempo­rarily removing the heater fuses.

71

12.2

12.2.1

Comments

EMC Directive

This equipment has been tested to meet the European Electromagnetic Compat­ibility Directive (EMC Directive, 89/336/EEC). The Declaration of Conformity
for your instrument lists the specific standards to which the unit was tested.

12.2.2

Low Voltage Directive (Safety)

In order to comply with the European Low Voltage Directive (73/23/EEC),
This equipment has been designed to meet the IEC 1010-1 (EN 61010-1) and
the IEC 1010-2-010 (EN 61010-2-010) standards.

12 Troubleshooting

12.3

Wiring Diagram

Figure 9 Wiring Diagram

72

Customer Support Centers

U.S.A.
For Sales and Services
(Repair/Calibration):

Amphenol Thermometrics, Inc.
St Marys Center
967 Windfall Road
St Marys, Pennsylvania 15857
U.S.A.
T: [phone]

U.S.A.
For Technical Support:

Amphenol Thermometrics, Inc.
St Marys Center
967 Windfall Road
St Marys, Pennsylvania 15857
U.S.A.
T: [phone]
F: [phone]

F: [phone]

Europe, Asia and Middle East
Sales and Service:

Amphenol Advanced Sensors GmbH
Sinsheimer Strasse 6
D-75179 Pforzheim
Germany
T: [phone]

4335 0

F: [phone]

When contacting Amphenol Advanced Sensors Customer Service, please have the
following information available:

Model Number, Serial Number, Voltage and Complete description of the problem.

China:

Amphenol (Changzhou)
Connector Systems
305 Room, 5D
Jintong Industrial Park
Wujin, Changzhou, Jiangsu, China
T:[phone] ext. 50087
F:[phone]

M4436 Rev. B, 12/19

www.amphenol-sensors.com

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Technical content subject to change without notice.