Dwyer GFM4 - Manual (Page 3)

1. UNPACKING THE GFM3/4 MASS FLOW METER
1.1 - Inspect Package for External Damage
Your GFM3/4 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 your distributor or Dwyer Instruments, Inc
. 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 - Maintenance/Repair
Upon final installation of the Series GFM3/4, no routine maintenance is required.
The Series GFM3/4 is not field serviceable and should be returned if repair is
needed. Field repair should not be attempted and may void warranty.
Warranty/Return
Refer to “Terms and Conditions of Sales” in our catalog and on our website. Contact
customer service to receive a Return Goods Authorization number before shipping
the product back for repair. Be sure to include a brief description of the problem
plus any additional application notes
2. INSTALLATION
2.1 - Primary Gas Connections
Please note that the GFM3/4 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.
Attitude limit of Mass Flow Meter is ±15deg from calibration position (standard
calibration is in horizontal position). This means that the gas flow path of the Flow
Meter must be within this limit in order to maintain the original calibration accuracy.
Should there be need for a different orientation of the meter, re-calibration may be
necessary. It is also preferable to install the GFM3/4 transducer in a stable
environment, 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 contaminants. 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 until the
ends of the properly sized tubing 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. Avoid over tightening which will seriously
damage the Restrictor Flow Elements (RFE's)!
GFM3 transducers are supplied with standard 1/4˝ or 3/8˝, or optional 1/8˝ inlet and
outlet compression fittings which should not be removed unless the meter is being
cleaned or calibrated for a new flow range.
Using a Helium Leak Detector, or other equivalent method, perform a thorough
leak test of the entire system. (All GFM3/4’s are checked prior to shipment for
leakage within stated limits. See specifications in this manual.)
2.2 - Electrical Connections
GFM3/4 is supplied with a 25-pin "D" connector. Pin diagram is presented in figure b-
1.
2.2.1 - Power Supply Connections
GFM3/4 transducers are supplied for three different power supply options:
±15Vdc (bipolar power supply)
DC Power (+) --------------- pin 1 of the 25-pin "D" connector
DC Power Common --------------- pin 18 of the 25-pin "D" connector
DC Power (-) --------------- pin 14 of the 25-pin "D" connector
+12Vdc or +24Vdc (unipolar power supply)
DC Power (+) --------------- pin 1 of the 25-pin "D" connector
DC Power (-) --------------- pin 18 of the 25-pin "D" connector
2.2.2 - Output Signals Connections
GFM3/4 Mass Flow Meters are equipped with either calibrated 0 to 5 VDC (0 to 10
VDC optional) or calibrated 4 to 20 mA output signals (jumper selectable). This
linear output signal represents 0 to 100% of the flow meter's full-scale range. Multi
Parameter versions (GFM3/4) are in addition equipped with either a calibrated 0 to
5 VDC (0 to 10 VDC optional) or a calibrated 4 to 20 mA output signal (jumper
selectable) for pressure and temperature. Pressure linear output signal represents
0 to 100 PSIA (46.9 kPa). Temperature linear output signal represents 0 to 50
° C.
Flow 0 to 5 VDC or 4 to 20 mA output signal connection:
Plus (+) ------------------- pin 2 of the 25-pin "D" connector
Minus (-) ------------------- pin 15 of the 25-pin "D" connector
Temperature 0 to 5 VDC or 4 to 20 mA output signal connection
Plus (+) -------------------- pin 3 of the 25-pin "D" connector
Minus (-) -------------------- pin 16 of the 25-pin "D" connector
Pressure 0 to 5 VDC or 4 to 20 mA output signal connection
Plus (+) -------------------- pin 4 of the 25-pin "D" connector
Minus (-) -------------------- pin 17 of the 25-pin "D" connector
To eliminate the possibility of noise interference, use a separate cable entry for the
DC power and signal lines.
2.2.3 - Communication Parameters and Connections
The digital interface operates via RS485 (optional RS-232 is available), and
provides access to applicable internal data including: flow, temperature, pressure
reading, auto zero, totalizer and alarm settings, gas table, conversion factors and
engineering units selection, dynamic response compensation and linearization
table adjustment.
Communication Settings:
Baud rate: -------- 9600 baud
Stop bit: -------- 1
Data bits: -------- 8
Parity: -------- None
Flow Control: -------- None
RS-485 Communication Interface Connection:
The RS485 converter/adapter has to be configured for: multidrop, 2-wire, half
duplex mode. The transmitter circuit has to be enabled by TD or RTS (depending
on which is available on the converter/adapter). Settings for the receiver circuit
usually should follow the selection made for the transmitter circuit in order to
eliminate echo.
RS-485 T(-) or R(-) -------- pin 11 of the 25-pin "D" connector (-)
RS-485 T(+) or R(+) -------- pin 24 of the 25-pin "D" connector (+)
RS-485 GND (if available) -------- pin 20 of the 25-pin "D" connector (GND)
RS-232 Communication Interface Connection:
Crossover connection has to be established:
RS-232 RX
(pin 2 on the DB9 connector) -------- pin 11 of the 25-pin "D" connector (TX)
RS-232 TX
(pin 3 on the DB9 connector) -------- pin 24 of the 25-pin "D" connector (RX)
RS-232 GND
(pin 5 on the DB9 connector) -------- pin 20 of the 25-pin "D" connector (GND)
GFM3/4 transducers should not be used for monitoring
OXYGEN gas unless specifically cleaned and prepared for such
application. For more information, contact your distributor or Dwyer ® Instruments,
Inc.
CAUTION
DO NOT CONNECT 24 Vdc POWER SUPPLY UNLESS YOUR
GFM3/4 METER WAS ORDERED AND CONFIGURED FOR 24
Vdc! (See power requirements label at the rear of the GFM3/4 meter)
CAUTION
When connecting the load to the output terminals, do not
exceed the rated values shown in the specifications. Failure to
do so might cause damage to this device. Be sure to check that the wiring and
the polarity of the power supply is correct before turning the power ON. Wiring
error may cause damage or faulty operation.
CAUTION
For models GFM4 (Multi Parameter versions) the maximum
pressure in the gas line should not exceed 100 PSIA
(6.8 bars). Applying pressure above 100 PSIA (6.8 bars) for extended periods of
time will seriously damage the pressure sensor and may cause serious injury or
death. Burst pressure is 200 PSIA (13.6 bar)!
WARNING
All 4 to 20 mA current loop outputs are self-powered (non-
isolated). Do not connect an external voltage source to the
output signals!
CAUTION
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