High pressure liquids an d gases a re pot ential ly haz ardous. En erg y stored in th ese
liquids and gases can be released unexpectedly and with extreme force. High
pressure systems sh ould b e assemb led and op erated only by p ersonnel w ho hav e
Information in this document is subject to change without not ice. No part of t his document may be reproduced or transm itt ed in any
form or by any means, electronic or mechanic al, for any purpos e, wit hout t he express written perm iss ion of Fl uke Corporation, DH
Instruments Division 4765 East Beautiful Lane Phoenix AZ 85044-5318 USA.
DH Instruments makes sincere efforts to ensure accuracy and quality of its’ publ ished materials; however, no warranty, expressed
or implied, is provided. DH Instruments disclaims any responsibility or liability for any direct or indirect damages resulti ng from the
use of the information in this manual or products described in it. Menti on of any product does not constitut e an endorsement by DH Instruments of that product. This manual was originally composed in English and was subsequently translated into other
languages. The fidelity of the translation cannot be guaranteed. In case of conflict between the English version and other language
versions, the English version predominates.
1.2.1 General Specifications ............................................................................................................................. 3
1.2.6 Front and Rear Panels ........................................................................................................................... 24
1.2.6.1 Front Panel .......................................................................................................................................... 24
2.2 Site Requirements ................................................................................................................................ 25
2.3.1 Preparing for Operation ......................................................................................................................... 26
2.3.2 Power Connection .................................................................................................................................. 26
2.3.3 molbox1+ to molbloc Connections ....................................................................................................... 27
2.3.4 Gas Supply and Flowpath Connections ............................................................................................... 27
2.3.7 MFC Control Option Connection ........................................................................................................... 29
2.4 Power UP and Verification ................................................................................................................... 29
2.4.1 Powe r UP ................................................................................................................................................ 29
2.5 Additional Precautions to Take Before Making Flow Measurements .............................................. 30
2.6 Short Term Storage .............................................................................................................................. 31
3.2 Main Run Screen .................................................................................................................................. 36
3.3.1 Keypad Layout and Protocol ................................................................................................................. 39
3.3.2 Direct Function Keys Summary ............................................................................................................ 40
3.4 Direct Function Keys............................................................................................................................ 41
3.6.6.1 COM1 and COM2 ...............................................................................................................................105
4.4 Statu s System ..................................................................................................................................... 138
4.4.1 Status Reporting System ......................................................................................................................138
4.4.1.1 Status Byte Register............................................................................................................................138
4.4.1.2 Standard Event Register .....................................................................................................................140
5. Maintenance, Adjustments and Calibration ...................... 141
5.2.1.1 PA and PM Coefficients ......................................................................................................................142
5.2.2 Equipme nt Require d .............................................................................................................................143
5.2.3 Set-Up and Preparation ........................................................................................................................143
5.2.4 Viewing and Editing RPT Readings and Calibration Information .......................................................144
7.1.2 Temperature ..........................................................................................................................................163
7.3.1.1 Detailed Signal Descriptions ................................................................................................................168
7.3.1.2 Popular Configurations ........................................................................................................................169
This manual pr ovides the user with the information necessar y to operate a molbox1+ and a molbox1 +S
molbloc terminal with molbloc mass flow elements to make mass flow measurements. Unless stated
otherwise, references to molbox1+ also include molbox1+S. It a lso includes a great d eal of additional
information provided to he lp you optimize use of a molbloc/ molbox1+ system and take full advantage of
its many features and functions.
Before using the manual, take a moment to familiarize yourself with the Table of Contents structure.
All first tim e molbox1+ users should rea d Sect ion 1. S ection 3.1 pr ovides a com prehensi ve desc ription of
general molbox1+ operating principles. Section 4. is for remote operation from an external computer.
Section 5 provides m aintenance and calibratio n information. Section 6 is a quick troub leshooting guide.
Use this section to troubleshoot unexpected molbox1+ behavior based on the symptoms of that behavior.
Cross references are used extensively to direct you towards additional information on a topic.
Cross references ar e generally in parentheses an d give the reference’s sect ion number. For example:
(see Section 11).
Certain words and expressions have specific meaning as they pertain to molbox1+. The Glossary
Section is useful as a quic k reference for exac t definition of specific words and expressions as they are
used in this manual.
Note
For those of you who “don’t read manuals”, go directly to section 2.3, initial setup,
to set up your molbox1+. Then go to section 2.4, power up and verification. This
will get you running quickly with minimal risk of causing damage to yourself or
your molbox1+. Then… when you have questions or start to wonder about all the
great features you might be missing, get into the manual!
Manual Conventions
Caution
“Caution” is used in throughout the manual to identify conditions or actions that
could cause harm to the molbox1+ or to the devices that are connected to the
molbox1+.
Warning
“Warning” is used in throughout the manual to identify actions that could pose a
hazard to the user of the molbox1+.
Note
“Note” is used throughout the manual to identify operating and applications advice
[ ] Indicates direct function keys (e.g., [RANGE]).
< > Indicates molbox1+ screen displays (e.g., <1yes>).
molbox1+ a nd m olbox1+S are support units for making gas f low m easurem ents using m olbloc m ass f low
elements. Although the molbox1+ and the molbox1+S are separate products their functions and
operation are virtua lly identical. The ke y difference is that molbox1+ S is designed f or higher flo ws and it
only supports molbloc-S mass f low elements. A molbox1+ sup ports bot h molbloc -L and m olbloc-S. Each
product reads calibration data from a molbloc EEPROM and measures molbloc upstream and
downstream pressur e using built-in high precision Referenc e Pressure Transducers (RPTs). There are
several RPT range specific m odels in the molbox1+ product line: molbox1+ A350K, molbox1+ A700K,
molbox1+S A1.4M and molbox1+ S A2M .
An ohmic measurement s ystem reads the resistance of the molbloc platinum resistance thermometers
from which the molbloc temperature is calculated. Using the molbloc calibration data, measured
pressures and temper ature and gas prop erties s tored in m emory, the flo w rate of the gas f lowing throug h
the molbloc is calculated.
Internal molbox1+ valves support on-board PRESSURE TRANSDUCER TARING, molbloc-S BPR MODES,
LEAK TESTING and SELF PROTECT ION functions as we ll as a GAS PURGE r outine. The m olbox1+S
does not support PRESSURE TRANSDUCER TARING as it does not support m olbloc -L oper ation a nd does
not include a bypass valve to conn ect the up strea m and downs tream RPTs.
molbox1+ provides a local user interf ace via a front panel key pad and displa y and includes advanced
on-board functions. Remote communication capability is supported with RS232 and IEEE-488 interfaces.
molbox1+ is equippe d to handle molblocs on two s ep ar ate cha nnels. This allows easy switching between
two different molblocs as well as certain special dual channel functions. Internal valving switches the
molbox1+ pressure transducers from one molbloc to the other as needed.
molbox1+ is intended f or a pplicati ons i n which minimizing meas urem ent uncer taint y is the m os t important
requirement and/or integrated control of mass flow controllers (MFCs) is needed. A second model,
molbox RFM, is available for applications where a compact presentation and lower cost are the most
dominant requirements.
molbox1+ replaces the Fluke/DHI molbox1 product line. molbox1+ introduces several product
improvements over molbox1 including:
•Support for Q-RPT pressure sensor technology to improve linearity and precision on pressure
measurements.
•Improved gas property uncertainty using data from NIST Reference Fluid Thermodynamic and
Transport Properties Database (REFPROP).
•Support of expanded molbloc modelization and polynomial linearization data structure and
calculations. This new molbloc data structure allows greatly improved flow measurement
performance across the supported operat ing pressure and flow /Reynolds number ranges. This new
model makes the Premium calibration option and resulting specifications possible.
•Support for “named” molbloc calibrations – allowing storage of multiple pressure-dependent
calibrations in each gas o n a molbloc. Also pr ovides for s tated operating lim its of pressure, f low and
Reynolds number to be stored on the molbloc so the molbox1+ can alert the user of operating
conditions that are outside of the calibrated parameters, avoiding out of tolerance measurements.
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
For easy identification, ne w molbox1+ terminals are produced with serial num bers of 2000 and higher.
Older molbox1 term inals may be eligible for upgrade to m olbox1+ hardware, softwar e and specifications
by Fluke/DHI.
1.1.1 molbloc Flow Elements
Two different types of molblocs may be used with molbox1+; molbloc-L (laminar) and
molbloc-S (sonic). m olbox1+ supports operation with new or upgraded molblocs that have
the updated data str ucture to tak e advant age of m olbox1+ version 6. 00 or later features, a nd
also supports operation with older molblocs that do not have a version 6.00 data format.
Premium calibrations and a ssociated specif ications ar e only an option for m olblocs that have
the version 6.00 format.
1.1.1.1 molbloc-L Flow Element
molbloc-L is the original molbloc laminar flow element. molbloc-L covers the
lower portion of the molbloc/molbox1+ system flow range. The key molbloc-L
measurement is the differential pressure across the element, which is roughly
proportional to the mass flow rate through it. molbloc-L elem ents are calibrated
to be used at an absolute pressure which remains nearly constant, while the
differential pressure varies with flow rate. Different operating pressure options
and their effect on molbloc flow range are described in Section 1.2.5.1.1.
In addition to the new data structure and modelization methods that became
available for molblocs with the introduction of m olbox1+, all molbloc-L elem ents
of range 1E1-L to 3E4-L produced or upgrad ed af ter the rele ase of m olbox1+ are
equipped standard with an upstream ¼” VCR flange, or f lowpath conn ectio n, that
has an integrated sint ered m etal filter. T his filter is intende d to be a l ast defens e
against particulate contamination of the molbloc-L internal flowpath which can
affect molbloc-L measurements. Every effort should still be made to supply clean
dry gas to the molbloc to ensure its measurement performance and long-term
stability. molblocs that have the integrated upstrea m filter are recognizable by
the visible filter element as shown below.
Figure 1: molbloc-L Upstream End Flange with Integrated Filter
New molbloc-L elements produced with molbox1+ calibration data structure,
premium calibration options, and integrate d filter hardware can be identified b y
having a serial number of 6000 or higher. Most older molbloc-L elements are
eligible for upgrade to this hardware/v er sion 6.0 0 format by Fluke/DHI.
Quick connectors equivalent to Swagelok® QM Series (M2-B200)
Ω
Stability of 100 and 110 Ω reference resistors
1.1.1.2 molbloc-S Flow Element
molbloc-S elements use critical (sonic) flow venturi nozzle technology to measure
flows which overlap with th e ranges of molbloc-L an d cover the hig her end of the
molbloc/molbox1+ system flow range. T he mass flow rate through a molbloc-S
element is roughly propor tional to the upstr eam absolute pres sure when the f low
is “choked”, so the m olbloc-S operating pressure can vary widely as the mass
flow rate is changed throug hout t h e f lo w range. T he li mits of molbloc-S operatin g
pressure and flow ranges are defined by the molbloc-S calibration type,
described in Section 1.2.5.2.2.
New calibration data structure and premium calibration options for molbloc-S
were also introduce d along with molbox1+. m olbloc-S elements produced with
this support will h av e s eri al number of 4000 or h igh er. O ld er molbloc-S elem ents
are eligible for upgrade to version 6.00 format by Fluke/DHI.
1.2 Specifications
1.2.1 General Specifications
Power Requirements
Fuse
Operating Temperature Range
Storage Temperature Range
Vibration
Weight
Dimensions
Microprocessor
Communication Ports
Reference Pressure
Transducers(RPTs)
Pressure Limits molbox1+ A350K
85 to 264 VAC, 50 to 60 Hz, 22 VA max. consumption
1A/250V, slow blow, 5x20mm, NSN: 5920008930491
15 to 35 °C
- 20 to 70 °C
Meets MIL-T-28800D
6.8 kg (15 lb) max.
32 cm W x 12 cm H x 30 cm D
(12.6 in. x 4.7 in. x 11.8 in.) approx.
Motorola 68302, 16 MHz
RS232 (COM1), RS232 (COM2), IEEE-488
molbox1+ A350K 2 x 300 kPa (44 psia) calibrated range
oscillating quartz crystal
molbox1+ A700K 2 x 600 kPa (87 psia) calibrated range
oscillating quartz crystal
molbox1+S A1.4M 1 x 1200 kPa (174 psia) calibrated range
oscillating quartz crystal, 1 x 300 psi silicon based
molbox1+S A2M 1 x 2000 kPa (290 psia) calibrated range
oscillating quartz crystal, 1 x 300 psi silicon based
Maximum working pressure 300 kPa absolute (36 psia)
Maximum pressure without damage 350 kPa absolute (50 psia)
molbox1+ A700K
Maximum working pressure 600 kPa absolute (87 psia)
Maximum pressure without damage 700 kPa absolute (115 psia)
molbox1+S A1.4M
Maximum working pressure 1200kPa absolute (203 psia)
Maximum pressure without damage 1500 kPa absolute (218 psia)
molbox1+S A2M
Maximum working pressure 2000 kPa absolute (290 psia)
Maximum pressure without damage 2200 kPa absolute (320 psia)
1.2.4 MFC Control Function (Optiona l) Specifications
Analog Output
Voltage Range
Analog Input
Valve Test Point
0 to 6.000 VDC
± 0.1 % FS
0.4 µA
± 0.1 % FS
± 0.1 % FS
0.4 µA
+ 2 to + 15 VDC (in reference to - 15 VDC)
2.5 mVDC
1.2.5 Flow Measurement Specifications
molbox1+ meas ures the f lo w t hrou gh molbloc flow elements. There are two di f ferent types of
molblocs, molbloc-L (laminar) (see Section 1.1.1.1) and molbloc-S (sonic) (see Section
1.1.1.2). Flow measurement specifications, calibration types, ranges and dimensions are
detailed separately for each molbloc type in section 1 .2.5.1 and 1.2.5.2. For both molbloc-L
and molbloc-S elements, there are separate performance specifications given for the
premium and standard calibr ation types that are offered. All f low measurem ent uncertainties
are valid only for measurents in a gas for which the molbloc is calibrated, and within the
range of pressures for which the calibration is specified.
1.2.5.1 molbloc-L
The flow range, useable operating pressure and absolute and differential
pressure associated with molbloc -L operation depend on the molbloc used and
its pressure-dependent calibration options (see Section1.2.5.1.3).
1.2.5.1.1 Standard molbloc-L Calibrations
Rate
0 to molbloc full scale depending on gas and molbloc pressure
dependent calibration type (see Section 1.2.5.1.3)
± 0.05 % of reading from 10 to 100 % FS,
± 0.005 % FS under 10 % FS
± 0.005 % FS under 10 % FS
± 0.07 % of reading from 10 to 100 % FS,
± 0.007 % FS under 10 % FS
± 0.09 % of reading from 10 to 100 % FS,
± 0.009 % FS under 10 % FS
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
Measurement
± 0.2 % of reading from 10 to 100 % FS,
(N2 and any molbox1+
Uncertainty
supported gas for which
the molbloc in use is
calibrated)
1 Precision: Combined linearity, hysteresis, repeatability.
2 Stability: Maximum change in zero and span over specified time period for typical molbox1+ and molbloc used
under typical conditions. As stability can only be predicted, stability for a specific molbloc and molbox1+ should
be established from experience.
3 Measurement uncertainty (accuracy): Maximum deviation of the molbox1+ flow indication from the true value of
the flow through the molbloc including precision, stability and DHI calibration standard measurement
uncertainty.
3
± 0.02 % FS under 10 % FS
1E5 molbloc
± 0.5% of reading from 25 to 100 % FS,
± 0.125 % FS under 25 % FS
1.2.5.1.2 Premium molbloc-L Calibrations
Measurement Update
1 second
Rate
Range
0 to molbloc full scale depending on gas and molbloc pressure
dependent calibration type (see Section 1.2.5.1.2)
Resolution
Linearity
0.0015 % FS
± 0.05 % of reading from 10 to 100 % FS,
± 0.005 % FS under 10 % FS
Repeatability
± 0.05 % of reading from 10 to 100 % FS,
± 0.005 % FS under 10 % FS
1
Precision
± 0.07 % of reading from 10 to 100 % FS,
± 0.007 % FS under 10 % FS
(1 year)
2
± 0.03 % of reading from 10 to 100 % FS,
± 0.003 % FS under 10 % FS
± 0.125 % of reading from 10 to 100 % FS,
3
± 0.0125 % FS under 10 % FS
1E5 molbloc-L Premium cal i brat i on not avail abl e
Stability
Measurement
Uncertainty
(N2 and any molbox1+
supported gas for which
the molbloc in use is
calibrated)
1 Precision: Combined linearity, hysteresis, repeatability.
2 Stability: Maximum change in zero and span over specified time period for typical molbox1+ and molbloc used
under typical conditions. As stability can only be predicted, stability for a specific molbloc and molbox1+ should
be established from experience.
3 Measurement uncertainty (accuracy): Maximum deviation of the molbox1+ flow indication from the true value of
the flow through the molbloc including precision, stability and DHI calibration standard measurement
uncertainty.
See your molbloc’s Calibration Report to determine the
calibration type of the molbloc y o u ar e using.
Different pressure dependent c alibration options for molbloc-L elements determine
the range of operating pressures over which a molbloc can be used within its
mass flow measurement specifications. The calibration option also affects the
molbloc flow range and the differential pressure associated with the flow range.
Measurement uncertainty (accuracy) specifications fo r molbloc-L are valid only
for gases with which the molbloc has been calibrated. All molbloc-L elements
are calibrated for N2. Calibratio ns with other gases ar e optional. DHI calibration
capability is not maintained at all times for all gases on all m olbloc designations .
A bold value indicates that the maximum flow is limited by the maximum Reynolds number value of 1 200 which is reached
before the normal differential pressure range is reached. In that case, the second value gives the minimum flow for which
measurement uncertainty (accuracy) is equal to the nominal uncertainty specification. Divide the second value by 10 when
using molbox RFM microrange option.
Where there is no value in the field (–), this indicates that the maximum Reynolds number is reached before the differential
pressure reaches 5 kPa (1 kPa in the case of the 1E5 molbloc), therefore calibration with that gas is not useful.
1
Due to low vapor pressure, only downstream calibration type is available.
2
The operating pressure range is greater than the vapor pressure value for this gas.
The flow range and operating pressure associated with molbloc-S operation
depend on the molbloc and molbox used and the the m olbloc calibration option
selected (see Section 1.2.5.2.3)
1 second
Depends on molbloc-S pressure dependent calibration type
(see Section 1.2.5.2.2)
0.0015 % of FS
± 0.05 % of reading
± 0.05 % of reading
1
± 0.06 % of reading
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
(1 year)
0.2 % of 200 kPa flow from 50 to 200 kPa
0.2 % of 50 kPa flow from 20 to 50 kPa
0.125 % of 200 kPa flow from 50 to 200 kPa
Predicted Stability
Measurement Uncertainty
With SP molbloc-S
calibration
2
± 0.05 % of reading
3
A350K ± 0.2 % of reading from 50 to 200 kPa
A700K ± 0.2 % of reading from 50 to 500 kPa
S A1.4M ± 0.2 % of reading from 100 to 500 kPa
± 0.2 % of 100 kPa flow from 50 to 100 kPa
S A2M ± 0.2 % of reading from 200 to 500 kPa
±
Measurement Uncertainty
With LP molbloc-S calibration
3
A350K ± 0.2 % of reading from 20 to 200 kPa
A700K ± 0.2 % of reading from 50 to 200 kPa
±
Measurement Uncertainty
With HP molbloc-S
calibration
[1] Precision: Combined linearity, hysteresis, repeatability.
[2] Stability: Maximum change in zero and span over specified time period for typical molbox1+ and molbloc used
under typical conditions. As stability can only be predicted, stability for a specific molbloc and molbox1+ should
be established from experience.
[3] Measurement uncertainty (accuracy): Maximum deviation of the molbox1+ flow indication from the true value of
the flow through the molbloc including precision, stability and DHI calibration standard measurement
uncertainty.
3
A700K ± 0.2 % of reading from 200 to 500 kPa
S A1.4M ± 0.2 % of reading from 200 kPa to 1.2 MPa
S A2M ± 0.2 % of reading from 200 kPa to 2 MPa
1.2.5.2.2 Premium molbloc-S Calibrations
Measurement Update
Range
Resolution
Linearity
Repeatability
Precision
Predicted Stability
(1 year)
Measurement
Uncertainty
With SP molbloc-S
calibration
Measurement
Uncertainty
With LP molbloc-S
calibration
Measurement
Uncertainty
With HP molbloc-S
calibration
[1] Precision: Combined linearity, hysteresis, repeatability.
[2] Stability: Maximum change in zero and span over specified time period for typical molbox1+ and molbloc used
under typical conditions. As stability can only be predicted, stability for a specific molbloc and molbox1+ should
be established from experience.
[3] Measurement uncertainty (accuracy): Maximum deviation of the molbox1+ flow indication from the true value of
the flow through the molbloc including precision, stability and DHI calibration standard measurement
uncertainty.
1 second
Rate
Depends on molbloc-S pressure dependent calibration type
(see Section 1.2.5.2.2)
0.0015 % of FS
± 0.05 % of reading
± 0.05 % of reading
1
± 0.06 % of reading
2
± 0.03 % of reading
A350K ± 0.125 % of reading from 50 to 200 kPa
3
A700K ± 0.125 % of reading from 50 to 500 kPa
S A1.4M ± 0.125 % of reading from 100 to 500 kPa
± 0.125 % of 100 kPa flow from 50 to 100 kPa
S A2M ± 0.125 % of reading from 200 to 500 kPa
±
A350K ± 0.125 % of reading from 20 to 200 kPa
3
A700K ± 0.125 % of reading from 50 to 200 kPa
± 0.125 % of 50 kPa flow from 20 to 50 kPa
A700K ± 0.125 % of reading from 200 to 500 kPa
3
S A1.4M ± 0.125 % of reading from 200 kPa to 1.2 MPa
S A2M ± 0.125 % of reading from 200 kPa to 2 MPa
See your molbloc’s Calibration Report to determine the
calibration type of the molbloc y o u are u sing .
Measurement uncertain ty ( accurac y) spec ificati ons f or molbl ocs ar e valid o nl y for
gases with which the molbloc has been calibrated. All molbloc-S elements are
calibrated in one standard gas, either air or N2, and may be calibrated in other
gases. Calibrations with other gases are optional. The l ist of gases which can
be measured by molbloc-S is the same as molbloc-L. DHI calibrat ion capability
is not maintained at all tim es for all gases on all molb loc desi gnations . Check for
availability before or dering cal ibra tions.
molbloc-S calibrations are performed over flow ranges corresponding to one of
three pressure ranges, summarized in Table 15.
Table 4: molbloc-S Calibration Types
CAL IBRATION TYPE
(CALIBRAT ION NAME)
Low pressure
(LP)
Standard pressure
(SP)
High pressure
(HP)
OPERATING PRESSURE
20 to 200 kPa absolute
(3 to 30 psia)
upstream of molbloc
50 to 500 kPa absolute
(7 to 70 psia)
upstream of molbloc
200 to 2000 kPa absolute
(29 to 290 psia)
upstream of molbloc
Note
molbloc-S flow measurements are valid only when the ratio of
pressure downstream to the pressure upstream of the nozzle is
low enough to assure a critical (choked) flow (see Section 3.1.5).
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
1.2.5.2.4 molbloc-S Ranges
molbloc-S flow ranges are def ined by the m olbloc’s Press ure to Flow Conver sion
Ratio, K
molbloc-S, the downstream pressure and the acceptable back pressure ratio
(see Section 3.1.5). K
relationship betwee n mass flow in nitrogen and the absolute ups tream pressure
delivered to the molbloc-S. molbloc-S sizes are defined by the nom inal K
molbloc-S nozzle, using scientific notation, for example a 1E3 molbloc-S has a K
of 1,000 sccm/kPa. To differentiate from molbloc-L size designations, this
molbloc size is designated 1E3-S.
The molbox1+ press ur e r a nge, the molb l oc -S cal ibra ti on type (s ee Sec t ion 1. 2.5. 2.2)
and the back pres sure ratio (BPR) requirements lim it the pressures, and flows,
over which a molbloc-S can be used within known measurement uncertainty
limits. In practice, the us able range of a molbloc -S in a given application also may
depend on the available gas supply pressure, th e presence and flow capacity of a
vacuum pump downstream or the allowable back pressure on an upstream DUT.
The mass flow range of a molbloc-S element is dependent on the properties of the gas
used, so the range of a molbloc-S is dif ferent for each supported gas. The flow ranges
for each molbloc-S size at various typical operating pressures are summarized
separate ly for each mo lbloc-S supported gas in the Tables below. For the com mon
applicat ion of using a molb loc-S with i ts do wnstre am pr essur e at or near atmosph eric
pressure , it is helpful to know what m inimum flow can be meas ured before viol ating
back pressure ratio requirements (see Section 3.1.5). In the tables below, this
minimum flow value is given in the “Mini mum withou t vacuu m” column.
, the gas used, th e absolute pr essure t hat can be delivered ups tream of
F
is expressed in units of sccm/kPa and defines the
F
of the
F
F
DHI calibra tion capability may not be ava ilable for some of the gases listed, or
may be limited to less than the m aximum flow rate listed. Check for availabilit y
before ordering calibrations.
The following notes apply to the range tables below:
Ratio = Inverse square root density ratio of the current gas to Nitrogen
KF = Pressure to Flow Conversion Ratio, sccm/kPa
To estimate a flow in a given gas at a gi v en pres s ure: F lo w(slm) = KF * Pressure
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
Table 6: Ar. molbloc-S Flow in Argon at Various molbloc Upstream Pressures
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
molbloc-S MASS FLOW RATE (slm @ 0 °C) WHEN molbloc-S UPSTREAM PRESSURE IS:[1][2]
20 kPa
50 kPa
100 kPa
Minimum
witout
(3)
200 kPa
500 kPa
700 kPa
1.2 MPa
2 MPa
10 0.5 1.3 2.6 9.4 5.3 13.2 18.5 31.8 52.9
20 1.1 2.6 5.3 13.1 10.6 26.5 37.1 63.5 105.9
50 2.6 6.6 13.2 25.7 26.5 66.2 92.6 158.8 264.7
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
Table 8: SF6. molbloc-S Flow in Sulfur Hexafluoride at Various molbloc Upstream Pressures
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximatel y 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures du e to the gas vap or pr essure.
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pr es su re to achieve critical flow with atmospheric pressure (approximately 100 kPa)
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
2 MPa
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
Table 16: CF4. molbloc-S Flow in Carbon Tetrafluoride at Various molbloc Upstream Pressures
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
2 MPa
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
n/a
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
Table 18: CHF3. molbloc-S Flow in Trifluoromethane at Various molbloc Upstream Pressures
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
[1] Flow values in table are valid only when critical flow is establishe d.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pr es su re to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximatel y 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are approximately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
downstream of molbloc-S (no vacuum).
[4] Operation in this gas is limited to lower pressures due to the gas vapor pressure.
[1] Flow values in table are valid only when critical flow is established.
[2] When volumetrically based mass flow units with reference temperatures other than 0°C are used, flow values
will generally be higher; the flow values for a given molbloc and upstream pressure are ap pro x im ately 7%
higher when expressed in slm at 20°C. Flow values at a given pressure may vary by up to ± 2% due to
flowpath machining tolerances.
[3] Minimum upstream pressure to achieve critical flow with atmospheric pressure (approximately 100 kPa)
nozzle extends beyond the molbloc
downstream flange, making the overall
length dimension, F, longer than the fitting
to fitting length dimension, K. The nozzle
overhang may interfere with some
molbloc-S downstream connections or the
connection of a blank off cap for leak
testing, so a 40 mm diameter ISO-KF
nipple is supplied with 5E3-S and 1E4-S
molblocs.
[2] Default connector type is listed. Additional
upstream connector options may be
available. Contact your DHI Sales
Representative for details.
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
1.2.6 Front and Rear Panels
1.2.6.1 Front Panel
The front panel assembly provides a 2 x 20 vacuum fluorescent display, a
membrane keypad for local user interface and other LED indicators.
2x20 Display
Multi-Function Keypad
Figure 1. molbox1+Front Panel
Channel Indicator
Remote Operation Indicator
1.2.6.2 Rear Panel
The rear panel assembly provides pressure and electrical connections for two molbloc
mass flow elements, communications interfaces and the power connection module.
Connection for External DMM (Option)
External Drivers Connection (Option)
MFC Switchbox Connection
RS485 Connection (not used)
Host Communications (IEEE-488)
MFC Analog Control Connection
Remote Communication for External Device (RS232)
Host Communications (RS232)
On/Off Sw i tch
Fuse
molbloc Electrical Connection (Channel B)
molbloc Pressure Connections (Channel B)
molbloc Pressure Connections (Channel A)
molbloc Electrical Connection (Channel A)
molbox1+ is delivered, along with its standard accessories, in a corrugated container with
foam end caps to hold it in place.
Remove the molbox1+ and its accessories from the shipping container and remove each
element from its protective plastic bag.
2.1.2 Inspecting Contents
Check that all items are present and have NO visible damage.
A molbox1+ includes:
ACCESSORIES INCLUDING:
1 Operation and Maintenance Manual 3540962
1 Power Cord (7.5 ft.) 3133781
4 molbox to molbloc pressure connecting tubes 3069560
2 molbox to molbloc electrical/data connection cables 3068683
2 Straight through quick connector stems 3068652*
1 Rubber Feet Cap Set (4) 3125347
1 MFC Cable and Connections Kit (if MFC Option
1 External 12 V Drivers Connector 3069839
1 General Accessories Disk (white)
* Equivalent to Swagelok P/N SS-QM2-S-200
Table 25: molbox1+ Parts List
DESCRIPTION PAR T #
molbox1+ mass flow terminal 3499975
molbox1+S mass flow terminal 3499975
Report of Calibration 3152121
included)
(Important: Includes system support software and
documentation.)
or 3153005-CE
or 3072220-CE
3114778
or 3114784-CE
3139043
2.2 Site Requirements
Install the molbox1+on any stable surface at a convenient height. The front feet are extendible so that the
unit can be inclined for eas ier vie wing. F our rub ber f eet caps ar e prov ided in the acces sories and can be
installed if desired. These prevent the unit from slipping on smooth surfaces.
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
The molbox1+ can also be mounted in a standard 19 in. rack mount using the optional rack mount
kit (P/N 3069903). For additional information, contact your DHI Representative.
When installing the molbox1+, consideration should be given to where the molbloc flow measuring
element and associated hardware will be located. molbox1+ may be placed on a shelf or cart at a
different height than the molbloc, but the distance between the molbloc and molbox is limited by the
length of the cable and pneumatic lines connecting them. If you will locate the molbox at a different
height than the m olbloc, the sm all errors that wou ld be assoc iated with th e difference in pr essure can b e
removed using the molbox1+ head correction (see Section 3.6.8).
If the molbloc/molbox system is being used to calibrate other devices (DUTs), the molbloc may need to be
connected upstream or downstream of the DUT to operate within the pressure limits of the molbloc’s
calibration type (see Se ctions 1.2.5.1.3, 1.2.5.2.3) and to accommodate the pressure requirements of the DUT.
See the molbloc’s Calibration Report to determine the calibration type of the molbloc you are using.
If the molbloc is connected upstream of the DUT, it is important to supply the molbloc with a stable
regulated gas sourc e. The volume pr esent between t he molbloc and the device to be cali brated should
be minimized, particularly for low flows.
In some cases, m olbloc-S is used with a vacuum source downstream to r educe the pressure at which
critical fl ow is reached. Cons ider the placemen t of the vacuum pum p and connections. G enerally, a larg e
vacuum pump is needed that should be isolated from the work area due to noise and oil vapor
considerations. If the vacuum pump and/or vacuum kit was purchased from DHI, see the instruction
sheets and/or manuals that are included with the hardware.
Optional molstics are offered for mounting molblocs. They provide a convenient means of addressing
supply regu lation, filterin g and interconnec tion issues with h igh quality, conf igured hardwar e. For additional
information, contact your DHI Representative.
Caution
If a DUT is located upstream of the molbloc and is contaminated, contaminates
may flow from the DUT to the molbloc and alter the molbloc calibration. If the DUT
must be connected upst ream of the molbloc, be sure it is clean before flowing and
consider installing a filter between the D UT and the molbloc.
2.3 Initial Setup
2.3.1 Preparing for Operation
To prepare molbox1+ for check out and operation:
Remove the plastic caps from the molbox1+ rear panel pressure connections.
Remove the protective plastic sheet from the front panel display.
Familiarize yourself briefly with the front and rear panels (see Section 1.2.6).
Follow the steps described in Sections 2.3.2 to 2.3.7.
2.3.2 Power Connection
Connect the power cable s upplied to molbox1+ an d to a power sourc e. Power requirem ents
are 85 to 264 VAC, 50 to 60 Hz, 22 VA max. consumption.
There are two molbloc connection channels on molbox1+. Each has two pressure
connections (upstream and downstream) and one electrical/data connection. Select a
channel to use or connect a separate molbloc to each channel.
For the pressure con nections, use the molbox1+ to molbloc pr essure tubes (P/N 3069560)
supplied with the molbox1+. Following the color c oding on the pressure lines, connect th e
upstream (HI) molbox1+ re ar panel quick connector to the ups tream port of the molbloc and
the downstream (LO) quick connector to the downstream port. To connect the quick
connectors, first pull back the knurled sleeve on the quick connector body, then insert the
quick connector stem and push firmly on the quick connectors until the y click into place to
assure that the connection is properly completed.
For the electrical/data conn ection , use t he m olbox to m olbloc elec trical/ data c onnect ion cab le
(P/N 3068683). Con nec t th e c able t o the molbloc and then to molbox1+ rear panel c onnec tor
labeled molbloc.
Caution
Avoid making or breaking molbl oc electrical connections to the molbox1+
while the molbox power is ON. Damage to the molbloc EEP ROM may resul t.
2.3.4 Gas Supply and Flowpath Conne c t ions
Connect a gas supply to the molbloc. Gas supply requirements are:
•T he gas supply mus t be clean and dry (espec ially free f rom oil and part iculates) to avoid
contaminating the molbloc.
•For c orrect meas urements, the gas must be of the sam e species as that selected b y the
molbox1+ GAS function (see Section 3.4.2). Gas purity affects the measurement
uncertainty of flow measurements as molbox1+ uses the thermodynamic properties of
the flowing gas in its flow calculatio ns. Generally, gases with purit y of 99.9 % or better
are used for molbloc measurem ents. Except when usi ng ambient air with molbloc -S, the
test gas should be free of any humidity (dewpoint less than – 40 °C).
•If the m olbloc is connect ed upstream of the DUT, the s upply pressure m ust be regulated
and stable within the limits of the molbloc-L pressure dependent calibration type (see
Section 1.2.5.1.2.1) or molbloc-S cal ibra tio n t ype (s ee s ec tion 1.2. 5.2. 2). If the molb loc is
connected downstream of the DUT, use regulators and valves to make sure that the
pressure that is delive red to the molbloc will be within th e limit s of the molbloc calibration type.
•Care should also be taken to make sure that the pressure and flow supplied to the
molbloc are always low enough to avoid over pressuring the molbox1+ RPTs(see
Sections 1.2.2, 3.1.4). If a DUT upstream of the molbloc is operated at high press ure, a
pressure reducing regulat or should be connected between the DUT and the m olbloc to
ensure that even momentary high pressure spikes do not reach the molbox RPTs.
Caution
•The gas supp lied to the molbloc should be clean and dry. Contam ination
of the molbloc flow passage with liquids, particulates or any other matter
will alter the molbloc calibration and can lead to out of tolerance flow
measurements.
•NEVER connect a pressure source to the molbloc that is greater than the
overpressure limit of your molbox1+. molbox1+ A350K overpressure limit
is 300kPa absolute/200 kPa gauge (44 psig/29 psig). molbox1+ A700K
overpressure limit is 650 kPa absolute/550 kPa gauge (95 psia/80 psig).
Overpress ure can d amage the molbox1+ intern al RPTs (see S ection 1. 2.2,
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
If you are using a DHI molstic: Install the molbloc into the molstic and connect a gas
supply following th e molstic instruc tion sheet or m anual. The f low through the m olbloc must
be in the direction of the arrow engraved on the molbloc.
If you are NOT using a DHI molstic: Connect a gas supply to the molbloc acc ording to the
molbloc instruction sheet and the pressure limits of the molbloc calibration type. A valve
should be installed betw een the press ure suppl y and the m olbloc to allo w flow to the m olbloc
to be interrupted. The flow through the molbloc must be in the direction of the arrow
engraved on the molbloc.
Adaptor kits are a vailable from DHI to m ake connections f rom the molbloc or m olstic fittings
to other common c onnector types. Ask you DHI Sales Repr esentative about your specific
adaptor requirements.
Caution
Operating at pressures other than those of the molbloc-L pressure
dependent calibration typ e (see Section 1.2.5.1.2) or molbloc-S calibration
type may result in out of tolerance flow measurements. Refer to the
molbloc Calibration Report to determine its calibration type.
2.3.5 Vacuum Supply (molbloc-S only)
In some cases m olbloc-S is operated with a vacuum downstre am of the molbloc to reduce
the back pressure so that critical flow can be reached at a lower upstream pressure (see
Section 3.1.5).
There is no lower limit to the pressure that may safely be applied to molbox1+ RPTs.
If you are using DHI supplied downstream vacuum connect kit and vacuum pump:
Install the kit and pump following the supplied instruction sheet or m anual. Carefully follow
the pump manufacturer’s recommendations for pump operation.
If you are NOT using DHI supplied downstrea m vacuum connect kit and vacuum pump:
Carefully evaluate vacu um pump specifications to be sur e that the vacuum source available
has the pumping speed necessary to safely handle the planned flows and to maintain low
enough pressure at planned flow rates.
Be sure to provide facilities to avoid flowing into the pum p when the pump is not ON as this
will cause pressure to build up on the pump and may dam age it. Norm ally, a shut-off valve
should be included between the pump and the molbloc-S.
It is preferable to install a check valve with very low cracking press ure between the molbloc
and the vacuum shut-off valve.
Adaptor kits are a vailable from DHI to m ake connections f rom the molbloc or m olstic fittings
to other common c onnector types. Ask you DHI Sales Repr esentative about your specific
adaptor requirements.
Caution
Operating at pressures other than tho se of the molbloc-S calib ration type
may result i n out of tolera nce flow measu rements (see Section 1.2.5. 2.2).
Refer to the m ol blo c Ca li bra t ion Rep ort to d eter m in e its ca li bra ti on ty pe .
2.3.6 Communications Connections
If molbox1+ is being interfaced to a com puter, connect an RS 232 cable to molbox1+ COM1
or an IEEE-488 cab le (cables not supplied) to the molbox1+ IEEE-488 interf ace. Configure
the interface (see Section 3.6.6).
If the molbox1+ is equippe d with the MFC c ontrol option, a c able and connec tion kit will ha ve
been supplied with t he molbox1+ acc essor ies. C onf igure th e cab le c orrectl y us ing the p inout
information provided in Section 7.3 and information from the MFC manufacturer.
2.4 Power UP and Verification
2.4.1 Power UP
Actuate the power s witch on the molbox1+ r ear panel. Observe the front panel d isplay as
molbox1+ initializes, error checks, calibrates its internal ohmic measurement system and
goes to the main run screen (see Section 3.2). The top left side of the main run screen
should display a flo w value near zero or <BPR HI >. If <NO BLOC> is displayed, molbox1+
has not been able to identif y a molbloc connection and loa d molbloc inform ation. Verify that
a valid molbloc is pro per ly connected (see Secti on 2.3.3) and press [SETUP], <1molbloc> to
load the molbloc (see Section 3.5.1). If molbox1+ is still unable to identif y a molbloc, the
molbloc may require reloading of EEPROM information or molbox1+ may require repair.
If the molbox1+ fails to reach the main run screen: Service may be required. Rec ord the
sequence of operations and displays observed and contact a DHI Authorized Service
Provider (see Section 7.4).
2.4.2 Check Proper Pressure Measurement Operation
Check that the molbox pressure measurements are operating properly. Proceed as follows:
Connect the molbloc to the molbox1+ (see Secti on 2.3.3).
Shut off the gas supply to the molbloc and open both molbloc ends to atmospheric
(ambient) pressure.
Press [P&T] and observe the display of the pressure measured by the upstream and
downstream absolute RPTs (see Section 3.4.5). Observe the upstream and
downstream pressures. These should indicate cur rent atmospheric pressure and be in
agreement within ± 0.02% of the nominal full scale calibrated range listed in section
1.2.2. If the two readings disagree b y more than this, one or both RPTs may be out of
calibration and service may be required.
Press [ESCAPE] to return to the main run screen.
Note
The pressure measurements indicated in the [P&T] screen are corrected
for TARE and AUTOZERO values. If the pressure readings disagree more
than the values indicated above refer to the manual sections regarding
these f unc tio ns be fore cons i der in g ca lib ra ti on or ser vi ce .
2.4.3 Check Proper Temperature Measurement Operation
Check that the molbox1+ temperature measurement is operating properly. Proceed as follows:
Connect a molbloc to the molbox1+ (see Section 2.3.3).
From the molbox1+ main run sc reen, press [P&T] twice to arrive at t he temper ature display
screen. Observe the temperature readings of the two molbloc PRTs (see Section 3.4.5).
If the molbloc has been in a stable temperature environment for 30 to 60 m inutes, the
temperature indicatio ns should be roughly ambient te mperature and the two indications
should agree withi n ± 0.2 °C. If the two r eadings disagr ee by more than ± 0.2 °C, there
may be a problem with t he molbloc or the molbox1+ TEMPERAT URE MEASUREM ENT
function and service may be required.
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
2.4.4 Check the MFC Control Function (Optional )
Using the front panel k eypad, display select MFC profile #1 f or a voltage MFC or #2 for a
current MFC (see Sect ion 3.4.8). Usin g [ENTER] to s elect MFC se tpoints a nd obser ving the
MFC display screens, chec k that the MFC control ope ration is normal. If operation does not
appear to be correct, check the MFC cable configuration and connection. Check the
recommendations in Section 2.5 and the Troubleshooting Guide in Section 6 prior to
contacting a DHI Authorized Service Provider (Section 7.4).
2.4.5 Leak Check
It is recommended that a ne w molbox1+ be leak check ed at s tar t-up to as s ure t hat no interna l
leaks developed during shipping and handling. See Section 3.4.4.3 to run the molbox1+
on-board INTERNAL LEAK CHECKING function.
2.4.6 Check/Set Security Level
molbox1+ has a security system based on user levels. By default, the securi ty system is s et
to “low”, which includes certain access restrictions, and there is no password required to
change the securit y lev el. See S ection 3.6.2 f or inf or m ation on th e secur ity le vel s ystem . As
part of the molbox1+ startup, set your desired security level and a password.
Caution
molbox1+ is delivered with the security level set to “low” to avoid
inadvertent altering of critical internal settings but with access to changing
security levels unrestricted. It is recommended that at least the low
security level be maintained at all times and password protection be
implemented if control over setting of security levels is desired.
2.5 Additional Precautions to Take Before Makin g Flow
Measurements
Before using the molbox1+ to make meaningful flow measurements, consider the following:
• The pressure measuring RPTs must be tared at the operating line pressure (see Section 3.4.4.1).
• Operating pressure and flow range should be within the limits of the molbloc calibration type and
molbloc size for the flowing gas (see Section 1.2.5).
•Be sure that the gas pressure connected to the molbloc is not great enough to overpressure the
molbox1+ internal RPT s.
• The gas type selected should be the gas flowing through the molbloc (see Section 3.4.2).
• For flow measurement uncertainty within molbox1+ specifications, the gas type should be a gas with
which the m olbloc has been calibr ated (s ee molb loc Cal ibratio n Repor t) or pr ess [SETUP], <1molbloc>,
[ENTER] to see if the gas is included in the molbloc calibration gas list (see Section 3.5.1).
•Be sure the flo w unit of m easure you are using is correct. The d efault f low units of s ccm and s lm for
any molbox1+ are referenc ed to 0°C and 101.325k Pa per SEMI E12-96. Man y diff erent types of f low
units of meas ure are commonly used and have simil ar names. Before selecting a unit of measure,
familiarize yourself with Section 3.4.3 and its subsections thoroughly.
•Do not su pply a gas or connect a DUT upstr eam of the molbloc that ma y contaminate the molbloc.
The filter assembly inside a molbloc-L is designed to work with a clean gas supply with limited
contaminants. T his f ilter a ss em bl y should b e c ons idered a last line of defens e a gai nst c ontamination
and additional filtration should always be considered.
•Troubleshooting: For information on typically encountered start-up and operational issues, see Section 6.
molbox1+ sup ports two m olbloc inp ut channels . The main pur pose of this c apabili ty is to switc h
conveniently between t wo molblocs without making and break ing connections, for example,
to switch between two ranges. It also allows two molblocs to be used simultaneously
(see Section 3.5.4).
The active molbox1+ channel is indicated by the lit LED under the display. The active
channel can be change d by pres sing t he [A/B] direc t func tion k ey (see Sec tion 3.4.7). When
a molbloc channel is activated, molbox1+ operates internal valves to connect the molbloc
pressure ports for that c hannel to the molbox1+ pressure transducer s. The temperature of
the molbloc connec ted to t he act ive cha nnel is m easured an d th e flo w calibr ation dat a f or the
molbloc most recently activated on that channel is used for calculating flow.
Channel A High Isolation: Open
Channel A Low Isolation: Open
Channel B High Isolation: Closed
Channel B Low Isolation: Closed
Bypass: Closed, molbox1+-S does not use this valve
or connection.
User-selected s e tti ngs s uch as g as, u nits , K f ac tor, etc . a re al l com m on b etwe en channels A and
B. When one of these settings is changed while channel A is active, that setting will also be made
for channel B, even if different molbloc types are connected to the two channels. The only setting
that is not common to both molbloc channels is the tare value (See Section 3.4.4).
3.1.2 molbloc-L and molbloc-S Operation
molbox1+ operates s omewhat differently dep ending on whether a molbl oc-L or molbloc-S is
connected to the active molbox1+ channel. m obloc-L and molbloc -S operation use dif ferent
displays and flow calculations and some menu items are present for only one type of molbloc.
Most molbox1+ s ett in gs, s uc h as gas, uni ts , K f ac tor , e tc ., are c om mon to both molbloc-L and
molbloc-S operation. C hanges made to these settings while operating one type of molbloc
will still be in eff ect when th e other t ype of m olbloc is connec ted. T he onl y setting that exists
for both molbloc types, but is stored independently for each type, is the tare value. See
section 3.4.4.1 for details on the tare function.
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
Several of the molbox1+ sc reen displa ys and functions described in this section are different
for molbloc-L and m olbloc-S operation. Where the dif ferences are major, the description of
these functions is divided into two parts.
3.1.3 Flow Ready/Not Read y Indicati on
The character to the left of the measured flow on the MAIN run screen provides a flow
Ready/Not Ready indicatio n. This indication is inte nded to provide the us er with a clear and
objective indication of when a stable flow has been achieved.
Ready <*> is indicated when the current stability (rate of change) of flow is less than the
stability limit. The us er can set t he stability lim it (see Section 3.5 .2). The Read y/Not Ready
indication is often used when comparing the molbox1+ and a test device to help deter mine
when steady state flow conditions are present so that a valid comparison reading can be made.
In addition to the co nditions listed in s ections 3.1.3.1 and 3.1.3.2 molblocs that have named
calibration support will flash the flow display and indicate a Not Ready condition when the
measured flow exc eeds the c alibrated f low ran ge by 5% or the m easured upstream pressure
exceeds the calibrate d pressure range b y 10 kPa above the maxim um pressure or 10 kPa
below the minimum pressure. The downsream pressure is used when a molbloc-L
downstream calibration is active.
3.1.3.1 molbloc-L Operation
In molbloc-L operation, t he Ready/N ot Ready indication also he lps guard against
using molblocs above th eir va lid rang e by monitoring the Reynolds number of the
flow. If the Reynolds num ber of the cur rent flow excee ds 1 300, the Ready (<*>)
indicator flashes. The current Reynolds number value can be viewed using
[P&T] (see Section 3.4.5). If molblocs are used within the pressure and flow
range limits for the flowing gas and the pressure dependent calibration type
(see Section 1.2.5), a Re ynolds number of 1 200 will never be exc eeded (1 300
is used as the warning limit to allow for individual molbloc differences).
↓> Flow Not Ready ( uns t ab le and decr eas ing) .
<
<
↑> Flow Not Ready (unstable and increasing).
<P> Flow Not Ready, flow flashes (pressure exceeds calibrated
pressure range by 10kPa)
<F> Flow Not Ready, flow flashes (flow exceeds calibrated max flow b y 5 %)
3.1.3.2 molbloc-S Operation
In molbloc-S operati on, the Ready/ Not Ready indicatio n is also used t o warn the
user when the BPR (back pressure ratio) is too high to ensure critical flow (see
Section 3.1.5). When the BPR is beyond the choking limit, molbloc-S flow
measurements may not be valid and the Ready indicator becomes <P>. The
Ready/Not Ready indicators based on flow stability are also used in molbloc-S
operation, but the <P> indicator takes priority over other indicators.
molbox1+ has two absolute RPTs, one measures molbloc upstream pressure,
the other measures molbloc downstream pressure and may provide a second
measurement of m olbloc upstream pressure in molbloc -S operation. In normal
operation, they are not used at pressures greater than the following maximum
working pressures:
Exposing the molbox1+ RPTs to pressures greater than the m aximum operating
pressure may dam age them . molbox1+ has a syste m of warnings and alarm s to
protect itself from overpressure (see Section 3.6.3.1).
3.1.5 molbloc-S BPR Limits
To make flo w measurem ents wit hin pred ictabl e measur ement unc erta inty limi ts with a molbloc -S
flow element, critica l (sonic) flow conditions m ust be present. Critical flow ex ists when the
gas velocity reaches the local speed of sound at the throat of the molbloc-S Venturi nozzle.
molbox1+ uses the back pressure ratio, or BPR (the ratio of the molbloc-S downstream
absolute pr essure to the ups tream absolute pres sure) to determin e whether the flo w is critical.
For Venturi nozzles in gener al, the BPR mus t remain below a certain va lue for critical flo w to
exist. Commonly accepted practice f or critical flo w orifice use s uggests that this limiting BPR
value, or “chok ing ratio”, is approximate ly 0.5. That is, the absolu te pressure downstre am of
the nozzle must be less than one half of the absolute pressure upstream of the nozzle.
Empirical study of the Vent uri nozzles used in molbloc-S shows that the actual chok ing ratio,
or maximum BPR for critical flow, varies between about 0.4 and 0.9 as a function of the
Reynolds number (Re) over which the molblocs are u sed. molbox1+ cont inually calculates
Re during flow measur ement and can m onitor the BPR to ensure t hat it does not exceed the
choking ratio at the current Re conditions. molbox1+ uses a conservative BPR limit to
indicate to the user when the BPR approaches the choking ratio, to ensure that flow
measurements are only made under “safe” critical flow conditions. molbox1+ includes
features to measure BPR, automatically alert the operator when the BPR is too high and
prevent measurements when flow is not critical (see Sections 3.1.3.1, 3.4.4.5, 3.6.9).
Maintaining a sufficiently low BPR must be considered by molbloc-S users when selecting
molbloc-S sizes and hardware setups to use for flow measurements. For example, if a
molbloc-S will be us ed with atmos pheric pressur e downs tream , then the m olbloc c an onl y be
used over a range of upstr eam pres sures starting at t he max imum pressur e for its calibrat ion
type down to a minim um pressure value at which the BPR becomes equal to th e BPR limit
calculated by molbox1+. S ince mass flow through m olbloc-S is proportion al to the upstream
absolute pressure, the f low range for the molbloc in this applicati on is defined by the BPR
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
limit also. To max im ize the r ange of a molbloc-S element, a vacu um pump can be connected
downstream to reduce the downstream pressure while flowing. When the downstream
pressure is kept suf ficiently low, the upstream pres sure, and thus the mass f low rate, can be
adjusted all the way down to the minimum value for the molbloc’s pressure dependent
calibration type without being limited by the BPR value.
Depending on the p lac ement of the molbloc-S in relation to the D UT and other hardw are, and
the availabilit y and capac it y of a vac uum pum p that m ay be used, the m olbloc -S d ownstr eam
pressure will var y in different applications. C alculating Re for dif ferent molbloc-S sizes and
flow rates, and estimating the choking ratio (maximum BPR limit) as a function of Re is
somewhat complex, s o Table 17 is offered as an exam ple of the minimum flow that can be
achieved with each molbloc-S size in nitroge n, witho ut ex ceeding molbox1+ BPR l imits, when
the molbloc-S downstr eam pressure is known: In actual operation, molbox1+ calcula tes the
Re and BPR ratio and can automatically provide an indication of whether the BPR is adequate for
measurem ents to be m ade. For an es timate of the min imum critical f low at various do wnstream
pressures in gases other than N2, conta ct y our DHI Representative.
Table 26: Minimum molbloc-S Critical Flow (slm) in Nitrogen at Various molbloc-S Downstream Pressures
[1] When volumetrically based mass flow units with reference temperatures other than 0 °C are used, flow values will
generally be higher; for example, the flow values for a given molbloc and upstream pressure are approximately 7 % higher
when expressed in slm @ 20 °C. Flow values at a given pressure may vary by up to 2 % due to flowpath machining
tolerances.
[2] Limited by 20 kPa minimum calibration pressure rather than back pressure ratio
3.2 Main Run Screen
The molbox1+ MAIN r un screen is its home displa y that is reached on power up an d from which other
functions and menus are accessed. It is the top level of all menu structures.
The MAIN run screen is displayed in normal operation. It indicates the current measured flow as well as a
variety of additional information, if desired.
The MAIN run sc reen display applies t o the molbloc on the active molbloc chann el indicated by the re d
LED below the molbox1+ display (A or B). T he appearance of the MAIN run scr een diff ers depending on
whether the active molbloc is a molbloc-L or a molbloc-S.
Some item s in the molbloc-L MAIN run screen may change or flash at times, to indicate that
certain limit s a re e x ceede d, a s de scr ibed in t he te xt a ccompanying the follow ing s cree n d i splay :
1. <*> Ready/Not Ready indication; <*> when Ready (flashes if
Reynolds number of the flow exceeds 1 300), <
(increasing) or <
rate evolution when Not Ready (see Sectio n 3.1.3).
2. <FLOWWWW>: Numerical value and sign of the flow
measured by molbox1+. Result of last flow averaging cycle if in
AVERAGE displa y (see Section 3.4.6.2). Flas hes if Reynolds
number of the flow exceeds 1,300. Flashing also occurs when a
named calibrat ion is acti ve an d the flow exceeds the calibrated
range by 5%, or t he m eas ur ed u ps tream p ress ur e e xceeds t he
calibrated pressure range by 10 kPa above the maximum
pressure or 10 kPa below the minimum pressure. The
downsream pressure is used when a m olbloc-L downstream
calibration is active. The fiel d displays “PMODEL” when the
pressure exceeds the molbox internal pres sure model for the
active calibration gas.
3. <UNIT> Current flow unit of measure (see Section 3.4.3). Flashes if BPR is higher than the choking limit.
4. <K>: Indication whether a gas conversion factor or ADJ flow adjustment is applied to the displayed flow
measurement. Possible indications include:
<K>: Indicates that a gas correction factor (K factor) is currently being applied to the measured flow (see
Section 3.4.1). <K> if a factor is being applied, blank if no factor is being applied.
<A>: Indicates that a flow adjustment adder and/ or m ultiplier) is c urrently being applied t o the m easured flow
using the ADJ function (see Section 3.5.3). <A> if ADJ is being applied, blank if no ADJ is
being applied. Alternating When both ADJ and a K fact or are appl i ed, t he i ndication alternates between
<k> and <A> at each screen update.
5. <GGGG>: Indic ates the current molbox gas selection (see Section 3.4.2). This should be the gas that is
flowing through the molbloc. The field will alternate with the named calibration name when a named
calibration is active and more than one calibration is available for the selected gas.
6. <D>: Indication of what is being displayed on the bottom line of the display as set by the DISPLAY function
(see Section 3.4.6). Possible indications include:
<R>: Current DISPLAY mode is RATE (see Section 3.4.6.1); or if <n avg> is in the bottom right hand corner
of the display, current DISPLAY mode is “average” and this is the instantaneous reading AVERAGE
screen (see Section 3.4.6.2).
> (decreasing)indicat ing direction of flow
>
<
<H> Current DISPLAY mode is HI/LO (see Section 3.4.6.3).
<
<=> Current DI SP LAY m ode is UNIT (see Section 3.4.6.5).
<D> Current DISPLAY mode is DEVIATION (see Section 3.4.6.6).
<F> Current DISPLAY mode is FREEZE (see Section 3.4.6.7).
Blank, No character Current DISPLAY mode is CLEAN (see Section 3.4.6.8).
7. <DISPLAY MODE DATA>: Information displayed depends on current display mode (see
Section 3.4.6).
8. <MFC1R>: If the molbox1+ has the MFC control option, MFC profile and MFC switchbox channel number are
displayed when MFC function is on. Foll owed by R if MFC is in reg ulation mode. This display is overridden
by < DI S PL AY M O DE D AT A> if the space is needed to display < DI SP L AY M O DE D AT A> ( Av er ag e , H i/ Lo , Total, Unit, Deviation).
• The M AIN run screen may be slightly different when MFC control is in use
• When a number is too large to show in the allocated display space,
> Current DISPLAY mode is AVERAGE (see Section 3.4.6.2).
> Current DISPLAY mode is TOTAL (see Section 3.4.6.4).
Note
or an A_B f unc ti on i s i n use (se e Sections 3.4.8, 3.4.7).
molbox1+ displays <********>.
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
↓
measured upstream pressure exceeds the calibrated
*FLOWWWW unitk GGGG
D DISPLAY MODE DATA MFC1R
•molbox1+ h as a SCREEN S AVER function that causes the display to dim if
NO key is pressed for 10 minutes. Pressing a key restores full powe r to
the displa y. The screen save r activation tim e can be changed or s creen
saving can be completely suppressed (see Section 3.6.5.1).
3.2.2 molbloc-S Operation
As with molb loc-L th ere are lim its on som e of the conditi ons that m ay exist if the u ser expects
to make accurate flow measurements with molbloc-S. The key condition that can be m onitored is
the back pressure ratio, or BPR , which determines whether critical flow through the molbloc is
achieved (see Section 3.1.5).
When the BPR is in a “safe” region for critical flow measurements, the appearance of the
MAIN run screen is identical to the MAIN run screen in molbloc-L operation (see Section
3.1.3.1). When the molbox1+ BPR limit is exc eede d, t her e ar e t wo pos sib le MAI N r un s cr een
indicators. A flashing flo w value and unit indicate that the BPR limit has been ex ceeded. In
this condition, the flow ma y not be critica l and flow m easurements should not be relied on to
meet specifications. W hen the BPR limit is exc eeded by a large margin, th e flow is almost
certainly not critical and t he calculated value may be non-sensical, so the f low value is not
shown and is replaced b y <BPR HI>. In this state, the BPR value rep laces the display field
on the second line of the molbox1+ terminal.
Note
When molbloc-S is in the BPR OFF mode (see Section 3.6.9), BPR is not
monitored and invalid flow values may be displayed in the molbloc-S MAIN
run screen with no indication that a the BPR value is high.
1. <*>Ready/Not Ready indication; <*> when Ready <↑>
(increasing) or <
rate evolution when Not Ready; <P>when BPR is higher
than choking limit. (see Section 3.1.5).
2. <FLOWWWW>: Numerical value and sign of the flow
measured by molbox1+. Result of last flow averaging cycle
if in AVERAGE display (see Section 3.4.6.2). Flashes if
BPR is higher than the choking limit. If BPR exceeds the
choking limi t by a large margin, <BPR HI> replac es the flow
value. The flow will f lash when a nam ed calibrat ion is active
and the flow exceeds the calibrated range by 5% or the
pressure range by 10 kPa above the maximum pressure or
10 kPa below the minimum pressure. The field displays
“PMODEL” when the pressure exceeds the molbox internal
pressure model for the active calibration gas.
3. <UNIT> Current flow unit of measure (see Section 3.4.3). Flashes if BPR is higher than the choking limit.
4. <K>: Indic ation whether a gas conversion factor or ADJ flow adjustment is applied t o the displayed flow
measurement. Possible indications include:
<K>: Indicates that a gas correction factor (K factor) is currently being applied to the measured flow (see
Section 3.4.1). <K> if a factor is being applied, blank if no factor is being applied.
<A>: Indicates that a flow adjustment adder and/ or m ultiplier) is c urrently being applied t o the m easured flow
using the ADJ function (see Section 3.5.3). <A> if ADJ is being applied, blank if no ADJ is
being applied. Alternating When both ADJ and a K fact or are appl i ed, the i ndic at i on alt ernat es between
<k> and <A> at each screen update.
5. <GGGG>: Indic ates the current molbox gas selection (see Section 3.4.2). This should be the gas that is
flowing through the molbloc. <AirW> indicates that air is selected and a humidity correction is being applied
(see Section 3.4.2.2). The f ield will alternate with the nam ed calibration name when a nam ed calibration is
active and more than one calibration is available for the selected gas.
6. <D>: Same as molbloc-L (see Section 3.1.3.1).
7. <D ISPLAY MOD E DATA>: Information displayed depends on current display mode (see Section 3.4.6).
8. <MFC1R>: Same as molbloc-L (see Section 3.1.3.1).
•The M AIN run screen may be slightly different when MFC control is in use
or an A_B f unc ti on i s i n use (see Sections 3.4.8, 3.4.7).
•When a number is too large to show in the allocated display space,
molbox1+ displays <********>.
•molbox1+ has a SCREEN SAVER function that causes the display to dim if
NO key is pre ssed for 10 minut es. Pressing a ke y restores fu ll power to
the displa y. The screen save r activation tim e can be changed or s creen
saving can be completely suppressed (see Section 3.6.5.1).
3.3 Manual Operation
molbox1+ is des igned to offer the optim um balance between sim ple, intuitive operation and
the availabilit y of a w ide var iet y of f unc tions w ith a high level of op er ator discretion. The loc a l
operator interface is thr ough the front panel’s 2 x 20 charac ter alpha-numeric display and a
4 x 4 multi-function keypad. Remote operation by RS232 or IEEE-488 interface is also
available (see Section 4).
3.3.1 Keypad Layout and Protocol
molbox1+ has a 4 x 4 keypad for local operat or access to direct functions, function m enus
and for data entry.
The Editing and Execution keys are for
execution, suspending execution, backing up in
menus and editing entries.
The Menu/Data keys provide access to function
menus from the MAIN run screen. The menu
name is on the bottom half of the key. The SETUP
menu is for more frequently used functions. The
SPECIAL menu is for less frequently used and
internal functions. These keys enter numerical
values when editing.
The Function/Data keys allow very commonly
used functions to be accessed directly from the
MAIN run screen by a single keystroke. The name of
the function is on the bottom half of the key (see
Section 3.3.2). These keys enter numerical values
when editing.
Figure 4. Keypad Layout
Pressing the [ENTER] key generally causes execution or forward movement in the menu tree.
Pressing the [ESCAPE] key generall y allo ws movement back in th e menu tree and/or causes
execution to cease or suspend without changes being implemented. Pressing [ESCAPE]
repeatedly eventua lly returns to the M AIN run screen. Fr om the MAIN run scr een, pressing
[ESCAPE] allows momentary viewing of the molbox1+ identification screen.
Pressing the [+/-] key changes a numerical sign when editing. It also toggles through
multiple screens when available.
Pressing the [
←] and [→] keys allows rever se and forward cursor movem ent when editing
data entry. These keys are also used to scroll through choices.
Menu selections can be made by pressing the number of the selection direc t ly or by pressing [
→] to place the cursor on the number of the desired selection and pressing [ENTER].
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
Note
Some screens go beyond the tw o lines provided by the display. This is
indicated by a flashing arrow in the second line of the display. Press [
→] to move the cursor to access the lines that are NOT visible or
and [
directly enter the number of the hidden menu choice if you know it.
3.3.2 Direct Function Ke ys Summary
Local operation of molbox1+ is through the front panel 4 x 4 pressure sensitive keypad. To
minimize t h e use of mul ti-la yere d m enu str uc tur es , the keypad numeric al ke ys also pr ov ide dir ect
access to the most com monly used fu nctions. The function accessed is labeled on th e bottom
half of the each key. Direct function keys are active whenever molbox1+ is in its MAIN run
screen. Table 27 summarizes the operation of the direct function keys. See corresponding
manual sections for full detail on each direct function.
Note
It may be useful to keep a copy of Error! Reference source not found.,
Summary of molbox1+ Direct Function Key Operations, near the
molbox1+, especially when first becoming acquainted with its operation.
Table 27: Summary of molbox1+ Direct Function Key Operations
←]
Direct Function Keys Are Active From The Main Run Screen
See Corresponding Manual Sections For Full Detai l
Menu of commonly used setup features including MFC profiles, stability setting and
Menu of less frequently used internal functions and settings including preferences, resets,
remote interfaces, BPR (back pressure ratio) when using molbloc-S.
Turn on the MFC control option, select MFC profile to use and MFC switchbox channel.
Set the resolution with which the measured flow and other values are displayed.
Run the TARE, LEAK CHECK, PURGE and AutoZ functions. The option to TARE is not
Display the current pressure measurements (first press).
Display the current molbloc temperature measurements (second press).
Define the DISPLAY function for the second line of the molbox1+ display. Choices include
rate, average, hi/lo, totalize, 2
secondary unit changes.
Select active molbloc channel.
available in a molbox1+S.
nd
unit, deviation, freeze, clean.
Set/change a DUT gas correction factor (K factor).
Set flow measurement gas. This is also the key used to access and select named gas
Set flow measurement unit. Choice of units can be customized.
To cause the fl o w v al ue c al c ul ate d by molbox1+ to be multiplie d by a factor, K. G enerally used
to apply a test device’s gas correc tion factor us ed when a test de vice is cali brated w ith a gas
other than its normal gas.
PRINCIPLE
Frequently, when testing or calibrating a flow meas uring device, it is not possible to f low the
gas with which that device will normally be operated (the process gas). This may be
because the process gas is tox ic or corrosive or sim ply because it is not avai lable. When t he
process gas c annot be us ed for c alibration, it is c omm on to use a diff erent gas for testing or
calibrating (the calib ration gas). In this case, a fac tor represent ing the re lationship b etween
the calibration gas and the process gas for the test device may be applied so that the
calibration gas simulates the process gas. The calibration gas that simulates the
process gas is often called a surrogate gas for the process gas.
The relationship between a test device’s process gas and calibration gas is frequently
called a K factor or gas conversion fac tor. The fac tor’s value depen ds on specif ic properties
of the test device and determining the value is the responsibility of the device manufacturer.
For example, Silane (SiH4 ) is a frequently used gas in semiconductor processing. SiH4 is
highly toxic and requires extensive handling precautions so it is not practical for use in
calibration and testin g. A m ajor manuf actur er of Mass Flo w Control lers ( MFCs) rec omm ends
that MFCs that are t o be used with Silane be tested with Sulfur Hexafluoride (SF6), a nontoxic, non-flammable gas, using a conversion factor of 0.970. In other words:
SF6 flow x 0.970 = equivalent SiH4 flow for the MFC
The K function in molbox1+ allows a gas conversion factor to be entered by which flow values
measured by molbox1+ will be multiplied. In this exam ple, 0.970 would be entered as K so
that the values indicated by molbox1+ when SF6 is flowing through the m olbloc simulate the
flow of SiH4 for that manufacturer's MFC.
When the K function is active, molbox1+ performs all of its flow calculations normally but
multiplies the current flow value by the value of the K factor prior to displaying it.
The gas selected on molbox1+ which is d isplayed in the upp er right corner of the molbox1+
display should always be the gas that is actually flowing through the molbloc.
Note
K factors or gas conversion factors are based on the properties of the
device being tested. Thei r avai labilit y and validi ty ar e the re spons ibil ity of
that device's manufacturer. molbox/molbloc does not use factors or
conversion coefficients b etween gases. Flow is calculated from molbloc
characteristics and specific gas properties for each gas supported by
molbox1+. The gas selected on molbox1+ (see Section 3.4.2) which is
displayed in the upper right corner of the molbox1+ displ ay shou ld always
be the gas that is actually flowing through the molbloc.
OPERATION
To enable a gas conversio n factor press [K] from an y
run screen. The display is:
If <2off>
be applied. If <1on> is selected, the next screen is:
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
The value of the gas convers ion factor can be edited as des ired. Pressing [ENTER] returns
to the MAIN run screen with the entered K factor active. The letter <K> is always
appended to the flow unit indication in the run screens when the K function is ON
(e.g., sccmK). A K factor value of 1 is handled as if the K function were OFF.
Caution
When the K function is ON, as indicated by a <K> following the current
flow unit in the first line of the MAIN run screen, the current molbox1+ flow
indication is:
(flow as calculated by molbox1+ for the selected gas) x (the current K
factor)
Thus, the flow indicated is actually in error (biased) by the reciprocal of the
K factor .
3.4.2 [GAS]
PURPOSE
To specify the gas that is currently flowing through the m olbloc so that molbox1+ uses the
correct gas properties in its flow calculations.
PRINCIPLE
molbox1+ calculates the flow through a molbloc from:
• molbloc geometric characteristics
• gas pressures
• gas temperature
• specific characteristics of the flowing gas
The gas characteristics include:
• gas density under standard conditions
• change in gas density with pressure and temperature
• gas viscosity under standard conditions (when needed)
• changes in gas viscosity with pressure and temperature
Proprietary algorithm s are used to calculate gas density and viscosity (when needed) under
the actual flowing pressure and temperature conditions from density and viscosity under
standard conditions.
The characteristics of molbox1+ suppor ted gases and corres ponding algori thms are stored in
molbox1+ m emory. To correctly calculate the f low of a gas, the correct inform ation for that
gas must be used. T he molbox1+ GAS func tion allows the us er to s pecif y the f lowing gas so
that molbox1+ will use the correct gas information in calculating the flow through the molbloc.
Selection of a g as using the GA S f u nction also s e l ect s the molbloc (geometric) calibr at i on d a ta to
be used for flo w calcu lation. If a calibrat ion has been stor ed in th e molbloc for the s elected g as,
the molbloc c alibration data for that gas are used. If a gas is selecte d that the molbloc is not
calibrate d for, t he m olb ox 1+ wi ll use t he coeff icie nts of the default gas, normally N2 for m olbloc -L
and Air for molbloc-S. In the case that there are multiple N2 or Air calibrations on the molbloc, the
coefficien ts for t he cal ibrati on ind icated as DEFA ULT on th e cal ibratio n repor t are used. W hen a
calibratio n has not been perf ormed on the molb loc in the gas selec ted using the GA S function,
flow measurements have NO associated uncertainty or tolerance.
The operation of the GAS function, is different for molb loc-L and molbloc-S due to the support of
humid air measurements with molbloc-S. They are described sepa rately below .
To specify the gas flowing through molbloc-L,
press [GAS]. The display is:
The gases a vailable ar e grouped in categor ies
to facilitate finding a specific gas and as a
reminder to the user wh en se lectin g a gas t hat
may require special precautions in use. There
example, the <1inert> selection display s:
A secondary menu displays when a specifically
calibrated gas i s se lec t ed. T h e m enu includes:
the name of the gas, calibration name
calibrated flow range, the calibration type
(PREM for prem ium or ST D for standard) and
the supported pressure range.
calibrations are available for the selected gas
arrow keys “<>” display after the pressure. Use
the left right arrow keys to select the other
calibrations.
on the molbloc a secondary menu displays
molbloc will be used to derive the flow of the
selected gas. Press enter to proceed.
He, HI 5.0 slm
STD 50-550 kPa <>
No Air cal, N2 coef
used [ENTER]
Select the desired gas. Pres sing [ENTER] returns to the last run screen with
the selected gas active. The selec ted gas is al ways displa yed in the upper r ight
hand corner of the MAIN run screen.
MOLBOX1+™/MOLBOX1+S, MOLBLOC TERMINAL OPERATION AND MAINTENANCE MANUAL
⋅−
⋅
⋅=
100
100
62188.
RH
PP
RH
P
W
gamb
g
1327760
9.14509
0528.53
0649289.0
:
3
2
1
0
−=
=
−=
=
C
C
C
C
where
Note
The gas selected on the molbox1+ should always be the gas
that is flowing through the molbloc. molbloc/molbox does not
use K factors or gas con version factors between gases. When
calibrating or testing a device with a surrogate gas, molbox1+
should be set to the surrogate gas. The K factor or gas
conversion factor, if used, defines the relationship between the
surrogate gas and the process g as for the device being tested,
not for molbox1+ ( see Section 3.4.1, PRINCIPLE). The K factor
is supplied by the manufacturer of the device being tested.
3.4.2.2 molbloc-S Operation
In addition to dry air, molbox1+ supports measurement of ambient (humid) air
flow with molbloc-S. W hen Air is selected as the m olbloc-S test gas, the user is
prompted to enter a value of the humidity ratio (also known as the absolute
humidity or water ratio) of the ambient air. The humidity ratio, W , is defined as
the ratio of water m ass to gas mass in the flowing air. It is different from the
relative hum idity value, wh ich is usual ly expressed as a percentage . Typical valu es
of W are between zero and 0.06. molbox1+ does not accept an entry for W
greater than 0.1.
Typically, humidity measuring instruments report relative humidity, which is
dependent on the ambient pressure and temperature. Users who do not hav e
the W value available can use DHI’s free Unit of Measure Converter software
utility or COMPASS for molbox or COMPASS for Flow calibration software to
calculate W from measured pressure, temperature, and relative humidity. Visit
www.dhinstruments.com, or see your DHI sales repres entative for a copy of the
Unit of Measure Converter software utility. Air relative humidity, pressure and
temperature are con verted to the humidit y ratio, W, following Dalton ’s Rule and
thermodynamic principals using water saturation properties:
is the water saturation pressure, which can be calculated as:
P
g
3
0
2
1
ambambambg
CTCTCTCP
+++=
32
If dry air will be meas ured, then the user should enter a W value of zero when
prompted. Zero is the default W value.
When a non-zero W value is entered, m olbox applies a correctio n to its air flow
measurement for the change in air density due to h umidity. If a correc tion for W
is being applied to air flow measurements, a <W> is placed to the right of the
<Air> gas indication in the MAIN run screen.