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Technical Data Sheet No. TD9411M Rev. V
Date of Issue: November 2024
OPERATING MANUAL
FOR GFM MASS FLOW METERS
P.O. Box 373
Michigan City, IN 46361 USA
Phone: (219) 879-8000
FAX: (219) 879-9057
e-mail: [email protected]
Internet: http://www.dwyer-inst.com
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Dwyer reserves the right to make changes to information and specifications in this
manual without notice.
CAUTION:
This product is not intended to be used in life support applications!
CAUTION:
K-Factors at best are only an approximation. K factors should not
be used in applications that require accuracy better than +/- 5 to 10%.
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TABLE OF CONTENTS
1. UNPACKING THE GFM MASS FLOW METER.........................................
1.1 Inspect Package for External Damage.................................................
1.2 Unpack the Mass Flow Meter...............................................................
1.3 Returning Merchandise for Repair.......................................................
2. INSTALLATION.......................................................................................
2.1 Primary Gas Connections...............................................................
2.2 Electrical Connections.....................................................................
2.3.1 Remote LCD Readouts.....................................................................
2.3.2 Panel Mounting Readouts...............................................................
3. PRINCIPLE OF OPERATION..................................................................
4. SPECIFICATIONS...................................................................................
4.1 CE Compliance.................................................................................
5. OPERATING INSTRUCTIONS.................................................................
5.1 Preparation and Warm Up................................................................
5.2 Flow Signal Output Readings..........................................................
5.3 Swamping Condition.......................................................................
6. MAINTENANCE........................................................................................
6.1 Introduction.....................................................................................
6.2 Flow Path Cleaning..........................................................................
6.2.1 Restrictor Flow Element (RFE)........................................................
6.2.2 GFM-110 models.............................................................................
7. CALIBRATION PROCEDURES.................................................................
7.1 Flow Calibration...............................................................................
7.2 Calibration of GFM Mass Flow Meters..............................................
7.2.1 Connections and Initial Warm Up.....................................................
7.2.2 ZERO Adjustment.............................................................................
7.2.3 SPAN Adjustment............................................................................
7.3 Linearity Adjustment..........................................................................
7.3.1 Connections and Initial Warm Up....................................................
7.3.2 ZERO Adjustment.............................................................................
7.3.3 25% Flow Adjustment (using R33 potentiometer)...........................
7.3.4 10% Flow Adjustment......................................................................
7.3.5 25% Flow Adjustment (using R52 potentiometer)..........................
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7.3.6 50% Flow Adjustment....................................................................
7.3.7 75% Flow Adjustment....................................................................
7.3.8 100% Flow Adjustment....................................................................
7.4 LCD Display Scaling.........................................................................
7.4.1 Access LCD Display Circuit..............................................................
7.4.2 Adjust Scaling..................................................................................
7.4.3 Change Decimal Point......................................................................
8. TROUBLESHOOTING.............................................................................
8.1 Common Conditions........................................................................
8.2 Troubleshooting Guide.....................................................................
8.3 Technical Assistance.......................................................................
9. CALIBRATION CONVERSIONS FROM REFERENCE GASES.......................
APPENDIX 1 COMPONENT DIAGRAM.......................................................
APPENDIX 2 GAS FACTOR TABLE (“K” FACTORS).....................................
APPENDIX 3 DIMENSIONAL DRAWINGS....................................................
PARTS OF THE FLOW METER..............................................
APPENDIX 4 WARRANTY..........................................................................
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1. UNPACKING THE GFM MASS FLOW METER
1.1 Inspect Package for External Damage
Your GFM Mass Flow Meter was carefully packed in a sturdy cardboard carton,
with anti-static cushioning materials to withstand shipping shock. Upon receipt,
inspect the package for possible external damage. In case of external damage to
the package contact the shipping company immediately.
1.2 Unpack the Mass Flow Meter
Open the carton carefully from the top and inspect for any sign of concealed shipping damage. In addition to contacting the shipping carrier please forward a copy
of any damage report to Dwyer directly.
When unpacking the instrument please make sure that you have all the items
indicated on the Packing List. Please report any shortages promptly.
1.3 Returning Merchandise for Repair
Please contact the customer service representative at Dwyer and request a
Return Authorization Number (RAN). Equipment returned without an RAN
will not be accepted. Dwyer reserves the right to charge a fee to the customer
for equipment returned under warranty claims if the instruments are tested to be
free from warrantied defects.
Shipping charges are borne by the customer. Meters returned “collect” will not be
accepted!
It is mandatory that any equipment returned for servicing be purged and neutralized of any dangerous contents including but not limited to toxic, bacterially infectious, corrosive or radioactive substances. No work shall be performed on a
returned product unless the customer submits a fully executed, signed SAFETY
CERTIFICATE. Please request form from the Service Manager.
CAUTION: Some of the IC devices used in the GFM are Electro Static
Discharge (ESD) sensitive and may be damaged by improper handling.
When wiring interface connector, adjusting or servicing the meter, use of a
grounded ESD protection wrist strap is required to prevent inadvertent
damage to the CMOS integral solid state circuitry. When 9 pins interface
D-connector is not used do not remove factory installed ESD protection cover.
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CAUTION: Some of the IC devices used in the GFM are Electro Static
Discharge (ESD) sensitive and may be damaged by improper handling.
When wiring interface connector, adjusting or servicing the meter, use of a
grounded ESD protection wrist strap is required to prevent inadvertent
damage to the CMOS integral solid state circuitry. When 9 pins interface
D-connector is not used do not remove factory installed ESD protection cover.
2
CAUTION: IT IS THE USERS RESPONSIBILITY TO DETERMINE IF THE
INSTRUMENT IS APPROPRIATE FOR THEIR OXYGEN APPLICATION, AND FOR
SPECIFYING O2 CLEANING SERVICE IF REQUIRED. DWYER IS NOT LIABLE
FOR ANY DAMAGE OR PERSONAL INJURY, WHATSOEVER, RESULTING
FROM THE USE OF THIS INSTRUMENT FOR OXYGEN GAS.
For more information contact Dwyer.
Attitude sensitivity of the Mass Flow Meter is ±15. This means that the gas flow
path of the Flow Meter must be horizontal within those stated limits. Should there
be need for a different orientation of the meter, re-calibration may be necessary. It
is also preferable to install the GFM transducer in a stab le en vironment, free of frequent and sudden temperature changes, high moisture, and drafts.
Prior to connecting gas lines inspect all parts of the piping system including ferrules and fittings for dust or other contaminant’s.
Be sure to observe the direction of gas flow as indicated by the arrow on the front
of the meter when connecting the gas system to be monitored.
Insert tubing into the compression fittings (except GFM-1145) until the ends of
the properly sized tubings home flush against the shoulders of the fittings.
Compression fittings are to be tightened according to the manufacturer's instructions to one and one quarter turns. Av oid ov er tightening which will seriously damage the Restrictor Flow Elements (RFE's)!
Using a Helium Leak Detector or other equivalent method perform a thorough
leak test of the entire system
. (All GFM's are checked prior to shipment for leak-
age within stated limits. See specifications in this manual.)
2.2 Electrical Connections
2. INSTALLATION
2.1 Primary Gas Connections
Please note that the GFM Mass Flow Meter will not operate with liquids. Only clean
gases are allowed to be introduced into the instrument. If gases are contaminated
they must be filtered to prevent the introduction of impediments into the sensor.
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PIN FUNCTION
1 Remote LCD display signal
2 0 to 5 VDC output indication
3 0 to 5 VDC common
4 Power supply, positive
5 Power supply, common
6 Remote LCD display reference
7 (unassigned)
8 4 to 20 mA output indication
self-powered (sourcing type,
non-isolated)
9 4 to 20 mA common (return)
3
FIGURE 2.a - 9-PIN “D” CONNECTOR PINOUTS FOR GFM TRANSDUCER.
Based on the GFM transducer’s serial number it may require a different power
sup-ply voltage. GFM flow meters with serial numbers below 340621-1 may
require 12 or 24 Vdc power supplies. Before connecting power supply check the
meter power supply requirements label located on the flow meter back cover. If
the power supply requirements label states that the power supply requirement is
12 Vdc, do not connect po wer supply with v oltage abo v e 15 Vdc. Exceeding specified maximum power supply voltage limit will result in de vice permanent damage.
The GFM flow meters with serial numbers above 340621-1have universal power
input and can be used with any power supply voltage between +12 and +26 Vdc.
CAUTION: BEFORE CONNECTING POWER SUPPLY CHECK YOUR METER
MODEL NUMBER AND POWER SUPPLY REQUREMENTS LABEL LOCATED ON
THE FLOW METER BACK COVER. DO NOT CONNECT 24Vdc POWER SUPPLY
UNLESS YOUR GFM METER WAS ORDERED AND CONFIGURED FOR 24Vdc.
EXCEEDING SPECIFIED MAXIMUM POWER SUPPLY VOLTAGE LIMIT MAY
RESULT IN DEVICE PERMANENT DAMAGE.
CAUTION: WIRING THE GFM METER WITH THE POWER ON MAY RESULT IN
INTERNAL DAMAGE! PLEASE MAKE ALL WIRING CONNECTIONS BEFORE
SWITCHING ON THE POWER.
All GFM models require power supplies with nominal current rating of at least
200 mA. The operating power input is supplied via the DC power jack or the 9pin “D” connector located at the side of the flow transducer enclosure. On
GFM's pur-chased without an LCD readout, a readout panel meter, digital
multimeter, or other equivalent device is required to observe the flow signal.
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IMPORTANT NOTES:
In general, “D” Connector numbering patterns are standardized. There are, however , some connectors with nonconf orming patterns and the numbering sequence
on your mating connector may or may not coincide with the numbering sequence
shown in our pin configuration table above. It is imperative that you match the
appropriate wires in accordance with the correct sequence regardless of the particular numbers displayed on your mating connector.
Make sure power is OFF when connecting or disconnecting any cab les in the system.
When connecting power to the GFM mass flow meter via the DC power jack, do
not connect any power supply to the 9-pin 'D' Connector. The DC power jack has
a center positive polarity.
When battery use is required to power the GFM, use only the optional battery and
accompanying charger available from Dwyer7.
Based on the device serial number the power input is protected by a 750mA (12
and 24 Vdc flow meter models with serial numbers below 340621-1) or 300 mA
(universal power flow meter models with serial numbers above 340621-1) M
(medium time-lag) resettable fuse. If a shorting condition or polarity reversal
occurs, the fuse will cut power to the flow transducer circuit. Disconnect the power
to the unit, remove the faulty condition, and reconnect the power. The fuse will
reset once the faulty condition has been removed.
CAUTION: Resettable fuse will not protect meter if power supply voltage
exceeds maximum voltage specified for particular model.
In order to operate flow meter within the specification the cable length for analog
0-5 Vdc output and remote LCD display may not exceed 9.5 feet (3 meters).
Use of the GFM flow transducer in a manner other than that specified in this manual
or in writing from Dwyer7, may impair the protection provided by the equipment.
2.3.1 Remote LCD Readouts
GFM Mass Flow Meters are available with optional remote reading LCD displays
supplied with a three foot long wire to accommodate most applications. This configuration includes the upper block element which serves as the LCD readout
mounting. Special lengths of remote extension wiring (up to 9.5 feet [3 meters])
are available on request.
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FIGURE 2.b - CUTOUT DIMENSIONS FOR LCD PANEL MOUNTING.
3. PRINCIPLE OF OPERATION
The stream of gas entering the Mass Flow transducer is split by shunting a small
portion of the flow through a capillary stainless steel sensor tube. The remainder
of the gas flows through the primary flow conduit. The geometry of the primary conduit and the sensor tube are designed to ensure laminar flow in each branch.
According to principles of fluid dynamics the flow rates of a gas in the two laminar
flow conduits are proportional to one another. Therefore, the flow rates measured
in the sensor tube are directly proportional to the total flow through the transducer.
In order to sense the flow in the sensor tube, heat flux is introduced at two sections of the sensor tube by means of precision wound heater-sensor coils. Heat is
transferred through the thin wall of the sensor tube to the gas flowing inside. As
gas flow takes place heat is carried by the gas stream from the upstream coil to
the downstream coil windings. The resultant temperature dependent resistance
differential is detected by the electronic control circuit. The measured gradient at
the sensor windings is linearly proportional to the instantaneous rate of flow taking
place.
An output signal is generated that is a function of the amount of heat carried by
the gases to indicate mass-molecular based flow rates.
2.3.2 Panel Mounting Readouts
Another option for the GFM Mass Flow Meter is the Panel Mounting Remote
Readout. In this configuration the LCD readout is supplied with a three foot long
extension wire, and no aluminum housing around the LCD. The LCD readout for
panel mounting includes a bezel with two plastic screws which conveniently fit
into a rectangular cut-out for panel mounting (see Figure 2.b).
NOTE: Dwyer reserves the right to change designs and dimensions at its sole discretion at any time
without notice. For certified dimensions please contact Dwyer.
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4. SPECIFICATIONS
FLOW MEDIUM: Please note that GFM 1101 thru 1145 Mass Flow Meters are designed to
work with clean gases only. Never try to meter or control flow rates of liquids with any GFM's.
CALIBRATIONS: Performed at standard conditions [14.7 psia (1.01 bars) and 70
F
F
(21.1
F
C)] unless otherwise requested or stated.
ENVIRONMENTAL (per IEC 664): Installation Level II; Pollution Degree II.
ACCURACY: GFM 110, 113 ±1.0% F.S.
GFM 1143, 1144, 1145 ±1.5% F.S.
REPEATABILITY: ±0.25% of full scale.
TEMPERATURE COEFFICIENT: 0.15% of full scale /
F
C.
PRESSURE COEFFICIENT: 0.01% of full scale /psi (0.07 bar).
RESPONSE TIME: 800 ms time constant; approximately 2 seconds to within ±2% of set
flow rate for 25% to 100% of full scale flow rate.
GAS PRESSURE: 1000 psig (69 bars) GFM-110/111-113 and 1140; 500 psig (34.5 bars)
GFM 1142/1143/1144 and 1145; optimum pressure is 20 psig (1.4 bars).
GAS AND AMBIENT TEMPERATURE: 32
F
F to 122 FF (0 FC to 50 FC).
14
F
F to 122 FF (-10 FC to 50 FC) - Dry gases only.
RELATIVE GAS HUMIDITY: Up to 70%.
LEAK INTEGRITY: 1 x 10
- 9
sccs He max. to the outside environment.
ATTITUDE SENSITIVITY: No greater than ±15 degree rotation from horizontal. Standard calibration is in horizontal position.
OUTPUT SIGNALS: Linear 0-5 VDC (1000 W minimum load impedance) and 4-20 mA
self-powered sourcing type, non-isolated (0-500 loop W resistance); 20 mV peak to peak
max noise.
Contact Dwyer for optional RS232 or IEEE488 interfaces.
TRANSDUCER INPUT POWER:
GFM models with 12 VDC power input (serial numbers below 340621-1):
12 VDC, 200 mA maximum;
GFM models with 24 VDC power input (serial numbers below 340621-1):
+24 VDC, 200 mA maximum;
GFM models with universal power input (serial numbers above 340621-1):
any voltage between +12 and +26 VDC, 200 mA maximum;
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Power input is protected by a 750 mA (GFM models with serial numbers below 340621-1)
or 300 mA (GFM models with serial numbers above 340621-1) M (medium time-lag) resettable fuse, and a rectifier diode for polarity protection.
WETTED MATERIALS:
GFM-110 thru 1145:
Anodized aluminum, brass, and 316 stainless steel with FKM
O-rings seals; BUNA-N®, EPR or FFKM O-rings are optional.
GFM-1101 thru 1145: 316 stainless steel with FKM O-rings seals; BUNA-N
®
, EPR or FFKM
O-rings are optional.
Dwyer makes no expressed or implied guarantees of corrosion resistance of mass flow
meters as pertains to different flow media reacting with components of meters. It is the
customers' sole responsibility to select the model suitable for a particular gas based on the
fluid contacting (wetted) materials offered in the different models.
INLET AND OUTLET CONNECTIONS:
GFM-110 /111 /113 - 1/4" compression fittings. Optional: 6mm compression,
1/4" VCR
®
,3/8" or 1/8" compression fittings (GFM-110).
GFM-1142 /1143 - 3/8" compression fittings.
GFM-1144 - 1/2" compression fittings.
GFM-1145 - 3/4" FNPT fittings or 3/4" compression fittings.
LCD DISPLAY: 3½ digit LCD (maximum viewable digits “1999”), 0.5 inch high characters.
On GFM 1101-1145 meters aluminum or stainless steel models the LCD display is built into
the upper block element and may be tilted over 90 degrees for optimal viewing comfort.
Remote or panel mounting remote reading is optional.
Standard readings are in direct engineering units for the given gas and flow rate (i.e. liters
/minute [slpm], standard cubic centimeters /minute [sccm], standard cubic feet /hour
[scfh], etc.). 0 to 100% LCD calibration scaling is available upon request at time of order.
Contact Dwyer when non-standard display settings are desired.
TRANSDUCER INTERFACE CABLE: Optional shielded cable is available mating to the GFM
transducer 9-pin “D” connector. In order to operate flow meter within the specification the
cable length for analog 0-5 Vdc output and remote LCD display may not exceed 9.5 feet (3
meters).
4.1 CE Compliance
Any model GFM bearing a CE marking on it, is in compliance with the below stat-
ed test standards currently accepted.
EMC Compliance with 89 /336 /EEC as amended; Emission Standard: EN
55011:1991, Group 1, Class B Immunity Standard: EN 55082-2:1992.
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TABLE II GFM-113
MEDIUM FLOW MASS
FLOW METERS*
TABLE III GFM-1142
HIGH FLOW MASS
FLOW METERS*
* Flow rates are stated for Nitrogen at
STP conditions [i.e. 70
F
F (21.1 FC)
at 1 atm].
For other gases use the K factor as a
multiplier from APPENDIX 2.
TABLE IV PRESSURE DROPS
FLOW RANGES
CODE
liters/min [N
2]
GFM-1111 /2111
0 to 15
GFM-1130 /2130
20
GFM-1131 /2131
30
GFM-1132 /2132
40
GFM-1133 /2133
50
CODE
scc/min [N
2]
GFM-1101 /2101
0 to 10
GFM-1102 /2102
0 to 20
GFM-1103 /2103
0 to 50
GFM-1104 /2104
0 to 100
GFM-1105 /2105
0 to 200
GFM-1106 /2106
0 to 500
CODE
liters/min [N
2]
GFM-1107 /2107
0 to 1
GFM-1108 /2108
0 to 2
GFM-1109 /2108
0 to 5
GFM-1110 /2110
0 to 10
CODE
liters/min [N
2]
GFM-1140 /2140
60
GFM-1141 /2141
80
GFM-1142 /2142
100
GFM-1143 /2143
200
GFM-1144 /2144
500
GFM-1145 /2145
1000
MODEL
FLOW RATE
[liters /min N
2]
MAXIMUM PRESSURE DROP
[mm H2O] [psid] [mbar]
GFM-110
up to 10
58
0.083
5.7
GFM-111 /113
15
63
0.09
6.4
20
300
0.44
30
30
800
1.18
81
40
1480
2.18
150
50
2200
3.23
223
GFM-1140
60
3100
4.56
314
GFM-1142
100
5500
8.08
557
GFM-1143
200
2720
4.0
280
GFM-1144
500
3400
5.0
340
GFM-1145
1000
6120
9.0
620
TABLE I GFM-110 /111
LOW FLOW MASS
FLOW METERS*
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ADJUSTING ZERO READING MORE THAN ± 3.0% F.S. FROM THE FACTORY
SETTINGS MAY AFFECT DEVICE CALIBRATION ACCURACY. IF SUCH
ADJUSTMENT IS REQUIRED IT IS RECOMMENDED TO PERFORM METER
RECALIBRATION TO PRESERVE DEVICE ACCURACY.
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5. OPERATING INSTRUCTIONS
5.1 Preparation and Warm Up
It is assumed that the Mass Flow Meter has been correctly installed and thoroughly leak tested as described in section 2. Make sure the flow source is OFF.
Apply power to the unit by plugging the power supply line into the DC power jack
(or 9-pin 'D' connector) on the side of the meter. Allow the Mass Flow Meter to
warm-up for a minimum of 15 minutes.
SUPPLYING DC POWER TO THE POWER JACK AND THE “D” CONNECTOR AT
THE SAME TIME WILL DAMAGE THE METER. DC POWER JACK POLARITY
IS CENTER POSITIVE.
During initial powering of the GFM transducer, the flow output signal will be indicating a higher than usual output. This is indication that the GFM transducer has
not yet attained it's minimum operating temperature. This condition will automatically cancel within a few minutes and the transducer should eventually zero. If
after the 15 minutes warm-up period, the display still indicates a reading of less
than ± 3.0 % of F.S., readjust the ZERO potentiometer [R34] through the access
hole. Before zero adjustment it is good practice to temporarily disconnect the gas
source, to ensure that no seepage or leak occurs in to the meter.
5.2 Flow Signal Output Readings
Initiate a controlled gas flow after warm up. The flow signal output can be viewed
either on the LCD display, remote panel meter, digital multimeter, or other display
device.
If an LCD display has been supplied with the GFM, the observed reading is in
direct engineering units (0 to 100% indication is optional).
Analog output flow signals of 0 to 5 VDC and 4 to 20 mA are attained at the appropriate pins of the 9-pin “D” connector (see Figure 2.a) on the side of the GFM
transducer.
Meter signal output is linearly proportional to the mass molecular flow rate of the
gas being metered. By default calibration is done against 0 to 5 VDC output signal. If 4-20 mA output signal is used for flow indication on the GFM, which was
calibrated against 0 to 5 VDC, the total uncertainty of the reading may be in the
range of +2.5% of full scale. Optional calibration for 4-20 mA output signal is
available upon request at time of order. The full scale range and gas for which
your meter has been calibrated are shown on the flow transducers front label.
For optional RS232 or IEEE488 interfaces please contact Dwyer.
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5.3 Swamping Condition
If a flow of more than 10% above the maximum flow rate of the Mass Flow Meter
is taking place, a condition known as “swamping” may occur. Readings of a
“swamped” meter cannot be assumed to be either accurate or linear. Flow must
be restored to below 110% of maximum meter range. Once flow rates are lowered
to within calibrated range, the sw amping condition will end. Operation of the meter
above 110% of maximum calibrated flow may increase recovery time.
6. MAINTENANCE
6.1 Introduction
It is important that the Mass Flow Meter /Controller is used with clean, filtered
gases only. Liquids may not be metered. Since the RTD sensor consists, in part,
of a small capillary stainless steel tube, it is prone to occlusion due to impediments or gas crystallization. Other flow passages are also easily obstructed.
Therefore, great care must be exercised to avoid the introduction of any potential
flow impediment. To protect the instrument a 50 micron (GFM 1101 to 1111) or 60
micron (GFM 1131 thru 1142) filter is built into the inlet of the flow transducer . The
filter screen and the flow paths may require occasional cleaning as described
below. There is no other recommended maintenance required. It is good practice,
however, to keep the meter away from vibration, hot or corrosive environments
and excessive RF or magnetic interference.
If periodic calibrations are required they should be performed by qualified personnel and calibrating instruments, as described in section 7. It is recommended that
units are returned to Dwyer for repair service and calibration.
CAUTION: TO PROTECT SERVICING PERSONNEL IT IS MANDATORY THAT ANY
INSTRUMENT BEING SERVICED IS COMPLETELY PURGED AND NEUTRALIZED
OF TOXIC, BACTERIOLOGICALLY INFECTED, CORROSIVE OR RADIOACTIVE
CONTENTS.
6.2 Flow Path Cleaning
Before attempting any disassembly of the unit for cleaning, try inspecting the
flow paths by looking into the inlet and outlet ends of the meter for an y debris that
may be clogging the flow through the meter. Remove debris as necessar y. If the
flow path is not unclogged, then proceed with steps below.
Do not attempt to disassemble the sensor. If blockage of the sensor tube is not alleviated by flushing through with cleaning fluids, please return meter for servicing.
NOTE: DISASSEMBLY MAY COMPROMISE CURRENT CALIBRATION.
6.2.1 Restrictor Flow Element (RFE)
The Restrictor Flow Element (RFE) is a precision flow divider inside the trans-
ducer, which splits the inlet gas flow by a preset amount to the sensor and main
flow paths. The particular RFE used in a given Mass Flow Meter depends on the
gas and flow range of the instrument.
10
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6.2.2 GFM-110 Models
1. Unscrew both the inlet & outlet compression fittings from the meter using an
11/16" open box wrench.
2. Unscrew the RFE sub ass’y from the unit’s inlet side using a flat 1/2" wide screwdriver.
3. Push a pin/ screw driver dia 3/32-1/8" thru the adapter’s holes, then unscrew
a retaining nut using a 1/4" Allan wrench.
The 50 micron filter screen will now become accessible.
4. De-attach the RFE element from its adaptor using a 5/32" Allan wrench.
5. Clean or replace each of the removed parts as necessary. If alcohol is used for
cleaning, allow time for drying.
Inspect the flow path inside the transducer for any visible signs of contaminant.
If necessary, flush the flow path through with alcohol. Thoroughly dry the flow
paths by flowing clean dry gas through.
Be sure that no dust has collected on the O-ring seal, prior reassembling.
6. Re-assemble the RFE sub ass’y, and then carefully screw it into the inlet side.
Do not attempt installing the RFE sub ass’y into the unit’s outlet side!!
7. Screw in the compression fittings.
Adaptor
O-ring #11
Filter Screen
Retaining Nut
RFE
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NOTE: OVER TIGHTENING WILL DEFORM AND RENDER THE RFE DEFECTIVE.
It is advisable that at least one calibration point be checked after re-installing
the inlet fitting- See section (g).
IT IS NOT RECOMMENDED TO ATTEMPT TO DISASSEMBLE, OR REPAIR
GFM37, GFM47, GFM57, GFM67 AND GFM77 MODELS. DISASSEMBLY
NECESSITATES RE-CALIBRATION.
7. CALIBRATION PROCEDURES
NOTE: REMOVAL OF THE FACTORY INSTALLED CALIBRATION SEALS AND/OR
ANY ADJUSTMENTS MADE TO THE METER, AS DESCRIBED IN THIS SECTION,
WILL VOID ANY CALIBRATION WARRANTY APPLICABLE.
7.1 Flow Calibration
Dwyer Instruments' Flow Calibration Laboratory offers professional calibration
support for Mass Flow Meters, using precision calibrators under strictly controlled
conditions. NIST traceable calibrations are a v ailable. Calibrations can also be performed at customers' site using available standards.
Factory calibrations are performed using NIST traceable precision volumetric
calibrators incorporating liquid sealed frictionless actuators.
,
,
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The calibration can then be corrected to the appropriate gas desired based on relative correction [K] factors shown in the gas factor table - see Appendix 2. A reference gas, other than nitrogen, may be used to better appro ximate the flow characteristics of certain gases. This practice is recommended when a reference gas
is found with thermodynamic properties similar to the actual gas under consideration. The appropriate relative correction factor should be recalculated - see section 9.
It is standard practice to calibrate Mass Flow Meters with dry nitrogen gas at 70
F
F (21.1 FC), 20 psig (1.4 bars) inlet pressure and 0 psig (0 bar) outlet pressure.
It is best to calibrate the GFM transducers to actual operating conditions. Specific
gas calibrations of non-toxic and non-corrosive gases are available at specific
conditions. Please contact Dwyer for a price quotation. It is recommended that a
flow calibrator of at least four times better collective accuracy than that of the
Mass Flow Meter to be calibrated be used. Equipment required for calibration
includes a flow calibration standard and a certified high sensitivity multimeter
(which together have a collective accuracy of ±0.25% or better), an insulated
(plastic) screwdriver, a flow regulator (example: metering needle valve) installed
upstream from the Mass Flow Meter and a pressure regulated source of dry filtered nitrogen gas (or other suitable reference gas).
The gas and ambient temperature, as well as inlet and outlet pressure conditions
should be set up in accordance with actual operating conditions.
FIGURE 7.a - CALIBRATION POTENTIOMETER AND JUMPER LOCATIONS
R52-25%
(IF ENABLED)
R33-SPAN
(25% or 10%)
R34-ZERO
R38-50%
J1A (R52)
R1
J1B (R38) J1C (R39)
INCREASE
DECREASE
R39-75% R40-100%
J1D (R40)
MODULAR JACK
D-CONNECTOR
POWER JACK
Page 18
7.2 Calibration of GFM Mass Flow Meters
All adjustments in this section are made from the outside of the meter, there is no
need to disassemble any part of the instrument.
GFM Mass Flow Meters may be field recalibrated /checked for the same range
they were originally factory calibrated for. When linearity adjustment is needed, or
flow range changes are being made proceed to step 7.3. Flow range changes
may require a different Restrictor Flow Element (RFE). Consult Dwyer for more
information.
7.2.1 Connections and Initial Warm Up
At the 9-pin “D” connector of the GFM transducer, connect the multimeter to output pins [2] and [3] for 0-5 VDC (or pins [8] and [9] for 4-20 mA)-(see Figure 2.a).
Power up the Mass Flow Meter for at least 30 minutes prior to commencing the
calibration procedure.
7.2.2 ZERO Adjustment
Shut off the flow of gas into the Mass Flow Meter . To ensure that no seepage or leak
occurs into the meter, it is good practice to temporarily disconnect the gas source.
Using the multimeter and the insulated screwdriver, adjust the ZERO potentiometer
[R34] through the access window for 0 VDC (or 4 mA respectively) at zero flow.
7.2.3 SPAN Adjustment
Reconnect the gas source. Using the flow regulator, adjust the flow rate to 100% of
full scale flow. Check the flow rate indicated against the flow calibrator. If the deviation is less than ±10% of full scale reading, correct the SPAN potentiometer [R33]
setting by using the insulated screwdriver through the access window, to eliminate
any deviation. If the deviation is larger than ±10% of full scale reading, a defective
condition may be present.
14
\
CAUTION: The minimum voltage on 0-5 Vdc output can be in the range of 7
to 25 mV. Trying to reduce voltage below this level may increase negative
zero shift. This shift may be invisible on devices without LCD display. Stop
R34 zero potentiometer adjustment if voltage on 0-5 Vdc output is in the
range from 7 to 25 mV and does not decrease any lower.
LIKELY REASONS FOR A MALFUNCTIONING SIGNAL MAY BE:
Occluded or contaminated sensor tube.
Leaking condition in the GFM transducer or the gas line and fittings.
For gases other than nitrogen, recheck appropriate “K” factor from Gas Factor Table.
Temperature and/or pressure correction errors.
Page 19
15
See also section 8. TROUBLESHOOTING. If after attempting to remedy the
above conditions, a malfunction still persists, return the meter for factory ser vice,
see section 1.1.
At this point the calibration is complete. However, it is advisable that several
additional points between 0 and 100%, such as 25%, 50%, and 75% flow be
checked. If discrepancies are found, proceed to step 7.3 for Linearity Adjustment.
7.3 Linearity Adjustment
7.3.1 Connections and Initial Warm Up
At the 9-pin “D” connector of the GFM transducer, connect the multimeter to output pins [2] and [3] for 0-5 VDC (or pins [8] and [9] for 4-20 mA)-(see Figure 2.a).
If calibration to a new flow range or different gas is being performed, it may be
necessary to remove any jumpers at J1.A, J1.B, J1.C , and J1.D before the beginning the linearizing procedure.
Power up the Mass Flow Meter for at least 30 minutes prior to commencing the
calibration procedure.
7.3.2 ZERO Adjustment
Shut off the flow of gas into the Mass Flow Meter. To ensure that no seepage or
leak occurs into the meter, it is good practice to temporarily disconnect the gas
source. Using the multimeter and the insulated screwdriver, adjust the ZERO
potentiometer [R34] through the access window for 0 VDC (or 4 mA respectively)
at zero flow.
7.3.3 25% Flow Adjustment (using R33 potentiometer)
Reconnect the gas source. Using the flo w regulator, adjust the flow rate to 25% of
full scale flow. Check the flow rate indicated against the flow calibrator.
Adjust the setting for potentiometer [R33] by using the insulated screwdriver
through the access window, until the output of the flow meter reads 1.25VDC
±63mV (or 8mA ±0.25mA).
Using the flow regulator, adjust the flow rate until the output of the flow meter
reads 0.5 VDC (or 5.6mA). Check the flow rate against the flow calibrator. If the
flow rate indicated by the calibrator is within 10% ± 1.5% of F.S. then skip paragraphs 7.3.4, 7.3.5 and proceed directly to paragraph 7.3.6, if not, perform 10%
flow adjustment according to paragraph 7.3.4.
CAUTION: The minimum voltage on 0-5 Vdc output can be in the range of 7
to 25 mV. Trying to reduce voltage below this level may increase negative
zero shift. This shift may be invisible on devices without LCD display. Stop
R34 zero potentiometer adjustment if voltage on 0-5 Vdc output is in the
range from 7 to 25 mV and does not decrease any lower.
Page 20
7.3.4 10% Flow Adjustment
Using the flow regulator, adjust the flo w rate to 10% of full scale flo w according to the
calibrator. Check the flow rate indicated against the flow calibrator. Adjust the setting
for potentiometer [R33] by using the insulated screwdriver through the access window, until the output of the flow meter reads 0.5VDC ±63mV (or 5.6mA ±0.25mA).
7.3.5 25% Flow Adjustment (using R52 potentiometer)
Using the flow regulator, adjust the flow rate to 25% of full scale flow according to
the calibrator. Check the flow rate indicated against the flow calibrator. The output
of the flow meter should read 1.25VDC ±63mV (or 8.0mA ±0.25mA). If the reading
is outside of that range, place the jumper at [J1.A] as appropriate to increase or
decrease the signal. Adjust the setting for potentiometer [R52] by using the insulated screwdriver through the access window, until reading is within specification.
7.3.6 50% Flow Adjustment
Using the flow regulator, increase the flow rate to 50% of full scale flow according
to the calibrator. Check the flow rate indicated against the flow calibrator. The output of the flow meter should read 2.50VDC ±63mV (or 12mA ±0.25mA). If the reading is outside of that range, place the jumper at [J1.B] as appropriate to increase
or decrease the signal. Adjust the setting f or potentiometer [R38] b y using the insulated screwdriver through the access window, until reading is within specification.
7.3.7 75% Flow Adjustment
Using the flow regulator, increase the flow rate to 75% of full scale flow according
to calibrator. Check the flow rate indicated against the flow calibrator. The output of
the flow meter should read 3.75VDC ±63mV (or 16mA ±0.25mA). If the reading is
outside of that range, place the jumper at [J1.C] as appropriate to increase or
decrease the signal. Adjust the setting for potentiometer [R39] by using the insulated screwdriver through the access window, until reading is within specification.
7.3.8 100% Flow Adjustment
Using the flow regulator, increase the flo w rate to 100% of full scale flow according
to calibrator. Check the flow rate indicated against the flow calibrator. The output
of the flow meter should read 5.00VDC ±63mV (or 20mA ±0.25mA).
If the reading is outside of that range, place the jumper at [J1.D] as appropriate to
increase or decrease the signal. Adjust the setting f or potentiometer [R40] b y using the
insulated screwdriver through the access window, until reading is within specification.
Repeat steps 7.3.3 to 7.3.8 at least once more.
7.4 LCD Display Scaling
It may be desirable to re-scale the output reading on the LCD readout supplied
with certain model GFM transducers.
16
Page 21
17
Re-calibration for a new flow range or different engineering units are two examples of when this may be necessary.
7.4.1 Access LCD Display Circuit
Carefully remove the LCD from the GFM or panel mounted surface. Remove the
aluminum housing on the side of the connection cable. Slide the LCD assembly
out of the aluminum housing.
7.4.2 Adjust Scaling
Using a digital multimeter connected to either the 0 to 5 VDC or 4 to 20 mA signal
at the 9-pin “D” connector, set the flow rate on the GFM to full scale flow (5 VDC
or 20mA). Maintain full scale flow, and adjust the potentiometer [R3] on the LCD
printed circuit board to desired full scale flow reading.
7.4.3 Change Decimal Point
To change the decimal place on the LCD display readout, simply move the jumper
to the appropriate location on the 8-pin header block. The numbers are printed to
the side of the connections. Do not attempt to place more than one jumper for
decimal setting.
8. TROUBLESHOOTING
8.1 Common Conditions
Your Mass Flow Meter was thoroughly checked at numerous quality control points
during and after manufacturing and assembly operations. It was calibrated
according to your desired flow and pressure conditions for a given gas or a mixture of gases.
It was carefully packed to prevent damage during shipment. Should you feel that
the instrument is not functioning properly please check for the following common
conditions first:
Are all cables connected correctly? Are there any leaks in the installation? Is the
power supply correctly selected according to requirements? When several meters
are used a power supply with appropriate current rating should be selected.
Were the connector pinouts matched properly? When interchanging with other
manufacturers' equipment, cables and connectors must be carefully wired for correct pin configurations. Is the pressure differential across the instrument sufficient?
JUMPER POSITION
MAXIMUM SCALABLE DISPLAY READING
“0”
1999
“3”
199.9
“2”
19.99
“1”
1.999
Page 22
18
8.2 Troubleshooting Guide
INDICATION
lack of reading or output
unstable or no
zero reading
full scale output at “no
flow” condition or with
valve closed
calibration off
LIKELY REASON
power supply off
fuse blown
filter screen
obstructed at inlet
occluded sensor tube
pc board defect
power supply problem
gas leak
pc board defective
defective sensor
gas leak
gas metered is not the same
as what meter was
calibrated for
composition of gas changed
gas leak
pc board defective
RFE dirty
occluded sensor tube
filter screen obstructed at
inlet
transducer
is not mounted properly
REMEDY
check connection of power
supply
disconnect GFM transducer
from power supply; remove
the shorting condition or
check polarities;
fuse resets automatically
flush clean or disassemble to
remove impediments or replace
flush clean or or return to
factory for replacement
return to factory for replacement
check power supply for
appropriate output
locate and correct
return to factory for replacement
return to factory for replacement
locate and correct
use matched calibration
see K factor tables in
APPENDIX 2
locate and correct
return to factory for replacement
flush clean or disassemble
to remove impediments
flush clean or return to
factory for replacement
flush clean or disassemble to
remove impediments or replace
check for any tilt or change
in the mounting of the
transducer; generally, units
are calibrated for horizontal
installation
(relative to the sensor tube)
Page 23
19
INDICATION
No zero reading after 15
minute warm up time and
no flow condition.
No zero reading after 15
minute warm up time and
no flow condition. Display
reading does not response
on zero adjustment.
No zero reading after 15
minute warm up time and
no flow condition. Display
reading does not response
on zero adjustment. But
analog output 0-5 Vdc can
be adjusted from 10mV
up to 0.5 Vdc with zero
potentiometer R34.
LCD Display remains blank
when unit is powered up.
But flow can be observed
on analog output 0-5 Vdc
(pis 2 and 3 of the
D-connector).
LCD Display remains blank
when unit is powered up.
No response on the flow
from analog output
0-5 Vdc (voltage is less
than 15 mV).
REMEDY
Readjust ZERO
potentiometer R34 through
the access hole
(see page 14 for details).
Measure voltage on pins 4
and 5 of the 9 pin
D-connector. If voltage is
less than 11.0Vdc replace
power supply with new one
(regulated 12.0 Vdc, 250 mA
minimum is recommended).
Carefully remove the LCD
from GFM. Remove the
aluminum housing on the
side of the connection cable.
Side the LCD assembly out
of the aluminum housing.
Check connection for all four
wires. If any wire is disconnected restore connection
and readjust zero potentiometer
R34 to get zero reading on
the display (ensure gas
source is disconnected and
no seepage or leak occurs in
to the meter).
Check LCD connector
(remove and reinstall LCD
connector)
See instructions for pos. 3
Measure voltage on pins 4
and 5 of the 9 pin
D-connector. If voltage is
less than 11.0Vdc replace
power supply with new one
(regulated 12.0 Vdc, 250 mA
minimum is recommended).
If polarity is reversed
(reading is negative) make
correct connection.
Return GFM to factory
for repair.
LIKELY REASON
Embedded temperature
has been changed.
Power supply voltage is
less than 11.0 Vdc.
Wire is disconnected
inside of the LCD Display.
LCD Display connector is
not attached to the GFM or
connection is loose.
Wire is disconnected
inside of the LCD Display.
Power supply is bad or
polarity is reversed.
PC board is defective.
Page 24
20
INDICATION
LCD Display reading does
not correspond the correct
flow range according analog
output 0-5 Vdc signal.
LCD Display reading and
analog output 0-5Vdc
signal are fluctuate in wide
range during the flow
measurement.
LCD Display reading does
correspond the correct flow
range, but 0-5 Vdc output
signal does not change
(always the same reading
or around zero).
LCD Display reading and
0-5 Vdc output voltage do
correspond the correct flow
range, but 4-20 mA output
signal does not change
(always the same or
reading around 4.0 mA).
Calibration is off (no more
than 3.0 % F.S.).
REMEDY
Readjust LCD Display
scaling for required full scale
flow
(see 7.4 on page 16).
Check external connections
to pins 2 and 3 of the
D-connector. Make sure the
load resistance is more
than 1000 Ohm.
Return GFM to factory for
repair.
Check external connections
to pins 8 and 9 of the
D-connector. Make sure the
loop resistance is less than
500 Ohm.
Return GFM to factory for
repair.
Shut off the flow of gas into
the GFM (ensure gas source
is disconnected and no
seepage or leak occurs in to
the meter). Wait for 15
minute. with no flow
condition and readjust zero
potentiometer R34 to get
zero reading on the display.
LIKELY REASON
LCD Display is adjusted for
wrong flow range or
engineering units.
Output 0-5 Vdc signal (pins
2 and 3 of the D-connector)
is shorted on the GND or
overloaded.
Output 0-5Vdc schematic is
burned out or damaged.
External loop resistance is
open or more than 500
Ohm.
Output 4-20 mA schematic
is burned out or damaged.
GFM has initial zero shift.
Page 25
21
INDICATION
LCD Display reading is
above maximum flow range
and output voltage 0-5 Vdc
signal is more than 5.5 Vdc
when gas flows through the
GFM.
Gas flows through the GFM,
but LCD Display reading
and output voltage 0-5 Vdc
signal do not responds on
the flow.
Gas does not flow through
the GFM with inlet pressure
applied to the inlet fitting.
LCD Display reading and
output voltage 0-5 Vdc
signal show zero flow.
Gas flows through the GFM,
but LCD Display reading
is negative and output
voltage 0-5 Vdc signal do
not responds on the flow
(reading near 10mV).
Gas flows through the GFM,
but LCD Display reading is
negative and does not
change according to gas
flow. Output voltage
0-5 Vdc signal corresponds
correct gas flow.
REMEDY
Lower the flow through GFM
within calibrated range or
shut down the flow completely. The swamping condition will end automatically.
Return GFM to factory for
repair.
Check maximum flow range
on transducer's front panel
and make required flow
adjustment.
Unscrew the inlet compression fitting of the meter and
reinstall RFE (see 6.2.2 on
page 12). NOTE: Calibration
accuracy can be affected.
Return GFM to factory for
repair.
Flush clean or disassemble
to remove impediments or
replace the filter screen
(see 6.2 on page 11).
NOTE: Calibration accuracy
can be affected.
Check the direction of gas
flow as indicated by the
arrow on the front of the
meter and make required
reconnection in the installation.
Locate and correct gas leak
in the system. If GFM has
internal leak return it to
factory for repair.
Carefully remove the LCD
from GFM. Remove the
aluminum housing on the
side of the connection cable.
Side the LCD assembly out
of the aluminum housing.
Check connection for green
wire (5.00 Vdc reference
voltage). If any wire is
disconnected restore connection.
LIKELY REASON
Sensor under swamping
conditions (flow is more
than 10% above maximum
flow rate for particular
GFM).
PC board is defective.
The gas flow is too low for
particular model of GFM.
GFM17 models: RFE is not
connected properly to the
inlet fitting.
Sensor or PC board is
defective.
Filter screen obstructed at
inlet.
Direction of the gas flow is
reversed.
GFM is installed in the
installation with back
pressure conditions and gas
leak exist in the system.
5.00 Vdc reference voltage
(green wire) is disconnected
inside of the LCD Display.
Page 26
22
INDICATION
GFM is disconnected from
the source of the gas (no
flow conditions) but LCD
Display reading is
fluctuating in wide range.
Output voltage 0-5 Vdc
signal also fluctuating. The
power supply voltage is 12
Vdc and stable.
Reading on the LCD Display
ten (hundreds) times less
or more than actual gas
flow. Output voltage
0-5 Vdc signal corresponds
correct gas flow.
REMEDY
Return GFM to factory for
repair.
Carefully remove the LCD
from GFM. Remove the
aluminum housing on the
side of the connection cable.
Side the LCD assembly out
of the aluminum housing.
Reinstall jumper to the
appropriate location on the
8-pin header block
(see 7.4.3 on page 16).
LIKELY REASON
Sensor or PC board is
defective.
Decimal point jumper is
installed in wrong position
on the LCD Display Circuit.
For best results it is recommended that instruments are returned to the factory
for servicing. See section 1.3 for return procedures.
8.3 Technical Assistance
Dwyer Instruments will provide technical assistance over the phone to qualified
repair personnel. Please call our Technical Assistance at (219)-879-8000. Please
have your Serial Number and Model Number ready when you call.
Page 27
Q
O2
= Q
a
= Q
r
X K = 1000 X 0.9926 = 992.6 sccm
where K = relative K factor to reference gas (oxygen to nitrogen)
1
d X Cp
where d = gas density (gram /liter)
C
p
= coefficient of specific heat (cal /gram)
Q
a
K
a
Q
r
K
r
where Qa = mass flow rate of an actual gas (sccm)
Qr = mass flow rate of a reference gas (sccm)
K
a
= K factor of an actual gas
Kr = K factor of a reference gas
23
=
9. CALIBRATION CONVERSIONS FROM
REFERENCE GASES
The calibration conversion incorporates the K factor. The K factor is derived from
gas density and coefficient of specific heat. For diatomic gases:
=
K
=
K
gas
Note: In the above relationship that d and Cp are usually chosen at the same
conditions (standard, normal or other).
If the flow range of a Mass Flow Meter remains unchanged, a relative K factor is
used to relate the calibration of the actual gas to the reference gas.
For example, if we want to know the flow rate of oxygen and wish to calibrate
with nitrogen at 1000 SCCM, the flow rate of oxygen is:
Page 28
24
APPENDIX 1
COMPONENTS DIAGRAM
GFM METERING PC BOARD
Page 29
APPENDIX 2
GAS FACTOR TABLE (“K” FACTORS)
25
CAUTION: K-Factors at best are only an approximation. K factors should not
be used in applications that require accuracy better than +/- 5 to 10%.
ACTUAL GAS
K FACTOR
Relative to N
2
Cp
[Cal/g]
Density
[g/I]
Acetylene C2H
2
.5829 .4036 1.162
Air 1.0000 .240 1.293
Allene (Propadiene) C3H
4
.4346 .352 1.787
Ammonia NH
3
.7310 .492 .760
Argon Ar
Argon AR-1
(>10 L/min)
1.4573
1.205
.1244
.1244
1.782
1.782
Arsine AsH
3
.6735 .1167 3.478
Boron Trichloride BCl
3
.4089 .1279 5.227
Boron Trifluoride BF
3
.5082 .1778 3.025
Bromine Br
2
.8083 .0539 7.130
Boron Tribromide Br
3
.38 .0647 11.18
Bromine PentaTrifluoride BrF
5
.26 .1369 7.803
Bromine Trifluoride BrF
3
.3855 .1161 6.108
Bromotrifluoromethane (Freon-13 B1) CBrF
3
.3697 .1113 6.644
1,3-Butadiene C4H
6
.3224 .3514 2.413
Butane C4H
10
.2631 .4007 2.593
1-Butene C4H
8
.2994 .3648 2.503
2-Butene C4H8 CIS
.324 .336 2.503
2-Butene C4H8 TRANS
.291 .374 2.503
Carbon Dioxide CO
2
Carbon Dioxide CO2-1 (>10 L/min)
.7382
.658
.2016
.2016
1.964
1.964
Carbon Disulfide CS
2
.6026 .1428 3.397
Carbon Monoxide C0
1.00 .2488 1.250
Carbon Tetrachloride CCl4
.31 .1655 6.860
Carbon Tetrafluoride (Freon-14)CF
4
.42 .1654 3.926
Carbonyl Fluoride COF
2
.5428 .1710 2.945
Carbonyl Sulfide COS
.6606 .1651 2.680
Chlorine Cl
2
.86 .114 3.163
Chlorine Trifluoride ClF
3
.4016 .1650 4.125
Chlorodifluoromethane (Freon-22)CHClF
2
.4589 .1544 3.858
Chloroform CHCl
3
.3912 .1309 5.326
Chloropentafluoroethane (Freon-115)C2ClF
5
.2418 .164 6.892
Chlorotrifluromethane (Freon-13) CClF
3
.3834 .153 4.660
CyanogenC2N
2
.61 .2613 2.322
CyanogenChloride CICN
.6130 .1739 2.742
Cyclopropane C3H
5
.4584 .3177 1.877
Page 30
26
ACTUAL GAS
K FACTOR
Relative to N
2
Cp
[Cal/g]
Density
[g/I]
Deuterium D
2
1.00 1.722 1.799
Diborane B2H
6
.4357 .508 1.235
Dibromodifluoromethane CBr2F
2
.1947 .15 9.362
Dichlorodifluoromethane (Freon-12) CCl2F
2
.3538 .1432 5.395
Dichlofluoromethane (Freon-21) CHCl2F
.4252 .140 4.592
Dichloromethylsilane (CH3)2SiCl
2
.2522 .1882 5.758
Dichlorosilane SiH2Cl
2
.4044 .150 4.506
Dichlorotetrafluoroethane (Freon-114) C2Cl2F
4
.2235 .1604 7.626
1,1-Difluoroethylene (Freon-1132A) C2H2F
2
.4271 .224 2.857
Dimethylamine (CH3)2NH
.3714 .366 2.011
Dimethyl Ether (CH3)2O
.3896 .3414 2.055
2,2-Dimethylpropane C3H
12
.2170 .3914 3.219
Ethane C2H
6
.50 .420 1.342
Ethanol C2H6O
.3918 .3395 2.055
Ethyl Acetylene C4H
6
.3225 .3513 2.413
Ethyl Chloride C2H5Cl
.3891 .244 2.879
Ethylene C2H
4
.60 .365 1.251
Ethylene Oxide C2H4O
.5191 .268 1.965
Fluorine F
2
.9784 .1873 1.695
Fluoroform (Freon-23) CHF
3
.4967 .176 3.127
Freon-11 CCl3F
.3287 .1357 6.129
Freon-12 CCl2F
2
.3538 .1432 5.395
Freon-13 CClF
3
.3834 .153 4.660
Freon-13B1 CBrF
3
.3697 .1113 6.644
Freon-14 CF
4
.4210 .1654 3.926
Freon-21 CHCl2F
.4252 .140 4.592
Freon-22 CHClF
2
.4589 .1544 3.858
Freon-113 CCl2FCClF
2
.2031 .161 8.360
Freon-114 C2Cl2F
4
.2240 .160 7.626
Freon-115 C2ClF
5
.2418 .164 6.892
Freon-C318 C4F
8
.1760 .185 8.397
Germane GeH
4
.5696 .1404 3.418
Germanium Tetrachloride GeCl
4
.2668 .1071 9.565
Helium He
Helium He-1 (>50 L/min)
Helium He-2 (>10-50 L/min)
1.454
2.43
2.05
1.241
1.241
1.241
.1786
.1786
.1786
Hexafluoroethane C2F6 (Freon-116)
.2421 .1834 6.157
Hexane C6H
14
.1792 .3968 3.845
Hydrogen H2-1
Hydrogen H
2-2
(>10-100 L)
Hydrogen H
2-3
(>100 L)
1.0106
1.35
1.9
3.419
3.419
3.419
.0899
.0899
.0899
Page 31
27
ACTUAL GAS
K FACTOR
Relative to N
2
Cp
[Cal/g]
Density
[g/I]
Hydrogen Bromide HBr
1.000 .0861 3.610
Hydrogen Chloride HCl
1.000 .1912 1.627
Hydrogen Cyanide HCN
.764 .3171 1.206
Hydrogen Fluoride HF
.9998 .3479 .893
Hydrogen Iodide HI
.9987 .0545 5.707
Hydrogen Selenide H2Se
.7893 .1025 3.613
Hydrogen Sulfide H2S
.80 .2397 1.520
Iodine Pentafluoride IF
5
.2492 .1108 9.90
Isobutane CH(CH3)
3
.27 .3872 3.593
Isobutylene C4H
8
.2951 .3701 2.503
Krypton Kr
1.453 .0593 3.739
Methane CH4
Methane CH
4-1
(>10 L/min)
.7175
.75
.5328
.5328
.715
.715
Methanol CH
3
.5843 .3274 1.429
Methyl Acetylene C3H
4
.4313 .3547 1.787
Methyl Bromide CH3Br
.5835 .1106 4.236
Methyl Chloride CH3Cl
.6299 .1926 2.253
Methyl Fluoride CH3F
.68 .3221 1.518
Methyl Mercaptan CH3SH
.5180 .2459 2.146
Methyl Trichlorosilane (CH3)SiCl
3
.2499 .164 6.669
Molybdenum Hexafluoride MoF
6
.2126 .1373 9.366
Monoethylamine C2H5NH
2
.3512 .387 2.011
Monomethylamine CH3NH
2
.51 .4343 1.386
Neon NE
1.46 .246 .900
Nitric Oxide NO
.990 .2328 1.339
Nitrogen N
2
1.000 .2485 1.25
Nitrogen Dioxide NO
2
.737 .1933 2.052
Nitrogen Trifluoride NF
3
.4802 .1797 3.168
Nitrosyl Chloride NOCl
.6134 .1632 2.920
Nitrous Oxide N2O
.7128 .2088 1.964
Octafluorocyclobutane (Freon-C318) C4F
8
.176 .185 8.397
Oxygen O
2
.9926 .2193 1.427
Oxygen Difluoride OF
2
.6337 .1917 2.406
Ozone
.446 .195 2.144
Pentaborane B5H
9
.2554 .38 2.816
Pentane C5H
12
.2134 .398 3.219
Perchloryl Fluoride ClO3F
.3950 .1514 4.571
Perfluoropropane C3F
8
.174 .197 8.388
Phosgene COCl
2
.4438 .1394 4.418
Phosphine PH
3
.759 .2374 1.517
Page 32
28
ACTUAL GAS
K FACTOR
Relative to N
2
Cp
[Cal/g]
Density
[g/I]
Phosphorous Oxychloride POCl
3
.36 .1324 6.843
Phosphorous Pentafluoride PH
5
.3021 .1610 5.620
Phosphorous Trichloride PCl
3
.30 .1250 6.127
Propane C3H
8
.35 .399 1.967
Propylene C3H
6
.40 .366 1.877
Silane SiH
4
.5982 .3189 1.433
Silicon Tetrachloride SiCl
4
.284 .1270 7.580
Silicon Tetrafluoride SiF
4
.3482 .1691 4.643
Sulfur Dioxide SO
2
.69 .1488 2.858
Sulfur Hexafluoride SF
6
.2635 .1592 6.516
Sulfuryl Fluoride SO2F
2
.3883 .1543 4.562
Tetrafluoroethane (Forane 134A) CF3CH2F
.5096 .127 4.224
Tetrafluorohydrazine N2F
4
.3237 .182 4.64
Trichlorofluoromethane (Freon-11) CCl3F
.3287 .1357 6.129
Trichlorosilane SiHCl
3
.3278 .1380 6.043
1,1,2-Trichloro-1,2,2 Trifluoroethane
(Freon-113) CCl
2
FCClF
2
.2031 .161 8.36
Triisobutyl Aluminum (C4H9)AL
.0608 .508 8.848
Titanium Tetrachloride TiCl
4
.2691 .120 8.465
Trichloro Ethylene C2HCl
3
.32 .163 5.95
Trimethylamine (CH3)3N
.2792 .3710 2.639
Tungsten Hexafluoride WF
6
.2541 .0810 13.28
Vinyl Bromide CH2CHBr
.4616 .1241 4.772
Vinyl Chloride CH2CHCl
.48 .12054 2.788
Xenon Xe
1.44 .0378 5.858
Page 33
29
APPENDIX 3
DIMENSIONAL DRAWINGS
NOTE: Dwyer reserves the right to change designs and dimensions at its sole discretion at any time
without notice. For certified dimensions please contact Dwyer.
GFM 1101 to 1109, 1111 to 1133 and 1142
MODEL
CONNECTION
COMPRESSION
FITTING
DIMENSION INCH (MM)
LCD VERSION
NO
LCD
MOUNTING
HOLE
A
B
C
D
E
F
G
H
J
K
GFM 1101
to 1109
¹/₄" Tube O
Diameter
5.72
(145.3)
1.00
(25.4)
1.13
(28.6)
3.09
(78.6)
5.10
(129.6)
0.5
(12.7)
4.61
(117.1)
0.16
(4.0)
0.16
(4.0)
6-32
x 0.13
GFM 1111
to 1133
¹/₄" Tube O
Diameter
6.10
(154.9)
1.38
(34.9)
1.25
(31.8)
4.13
(104.8)
6.13
(155.8)
0.63
(15.9)
4.99
(126.7)
0.28
(7.1)
1.08
(27.3)
6-32
x 0.10
GFM
1142
³/₈" Tube O
Diameter
6.10
(154.9)
1.38
(34.9)
1.25
(31.8)
4.13
(104.8)
6.25
(158.7)
0.63
(15.9)
4.99
(126.7)
0.28
(7.1)
1.08
(27.3)
6-32
x 0.10
2.88
2.36
0.95
K
D
E
0.69
H
NO LCDVERSION
G
1.10
A
C
B
F
J
2.69
Page 34
30
MODEL
CONNECTION
COMPRESSION
FITTING
(Except Model
GFM 1145)
DIMENSION INCH (MM)
LCD VERSION
NO
LCD
MOUNTING HOLE
A
B
C
D
E
F
G
H
J
K
L
M
GFM
1143
³/₈" Tube O
Diameter
6.73
(170.8)
2.00
(80.8)
1.75
(44.5)
6.69
(169.8)
8.81
(223.7)
0.88
(22.2)
5.62
(142.6)
4.69
(119.0)
1.39
(35.3)
1.00
(25.4)
0.18
(4.6)
10-24
x 0.25
GFM
1144
¹/₂" Tube O
Diameter
7.64
(194.0)
3.00
(76.2)
3.00
(76.2)
7.25
(184.2)
9.65
(245.1)
1.5
(38.1)
6.53
(165.8)
6.75
(171.5)
2.25
(57.2)
0.25
(6.4)
0.38
(9.5)
1/4-20
x 0.35
GFM
1145
³/₄" NPT
Female
8.66
(220.0)
4.00
(101.6)
4.00
(101.6)
7.30
(185.4)
-
2.00
(50.8)
7.55
(191.8)
6.80
(172.7)
3.00
(76.2)
0.25
(6.4)
0.50
(12.7)
1/4-20
x 0.35
NOTE: Dwyer reserves the right to change designs and dimensions at its sole discretion at any time
without notice. For certified dimensions please contact Dwyer.
GFM 1143, 1144 and 1145
0.95
2.36
2.88
D
E
M
K
1.10
F
C
H
A
G
B
J
L
Page 35
31
PARTS OF THE FLOW METER
LEFT AND RIGHT VIEWS
FRONT VIEW
Page 36
32
APPENDIX 4
NOTE: Follow Return Procedures In Section 1.3.
WARRANTY
Dwyer Mass Flow Systems are warranted against parts and
workmanship for a period of one year from the date of purchase.
Calibrations are warranted for up to six months after date of
purchase, provided calibration seals have not been tampered with. It
is assumed that equipment selected by the customer is constructed
of materials compatible with gases used. Proper selection is the
responsibility of the customer. It is understood that gases under
pressure present inherent hazards to the user and to equipment, and
it is deemed the responsibility of the customer that only operators
with basic knowledge of the equipment and its limitations are
permitted to control and operate the equipment covered by this
warranty. Anything to the contrary will automatically void the liability
of Dwyer and the provisions of this warranty. Defective products will
be repaired or replaced solely at the discretion of Dwyer at no
charge. Shipping charges are borne by the customer .This w arranty is
void if the equipment is damaged by accident or misuse, or has been
repaired or modified by anyone other than Dwyer or factory
authorized service facility. This warranty defines the obligation of
Dwyer and no other warranties expressed or implied are recognized.
Page 37
TRADEMARKS
Buna®-is a registered trademark of DuPont Dow Elastometers.
Dwyer®-is a registered trademark of Dwyer Instruments.
Page 38
P.O. Box 373
Michigan City, IN 46361 USA
Phone: (219) 879-8000
FAX: (219) 879-9057
e-mail: [email protected]
Internet: http://www.dwyer-inst.com
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