Computer Weld GTFM IV User manual

10702 Old Bammel N Houston Rd.
Houston, TX 77086
Phone: [phone]
Fax: [phone]
Email: [email protected]
Computer Weld Technology, Inc.
GTFM IV
Gas Turbine Flow Monitor
Operation / Installation Manual
Manual Part Number: A8M5010
Revised: June 26, 2008

Table of Contents
1.0 OVERVIEW..................................................................................................................... 1
1.1 SYSTEM REQUIREMENTS....................................................................................................................... 1
1.2 BENEFITS ................................................................................................................................................... 1
1.3 FEATURES.................................................................................................................................................. 1
1.4 MECHANICAL SPECIFICATIONS............................................................................................................ 1
1.5 SENSOR SPECIFICATIONS..................................................................................................................... 2
1.6 MODELS...................................................................................................................................................... 2
2.0 INSTALLATION.............................................................................................................. 3
2.1 OPTIONS..................................................................................................................................................... 3
2.2 GAS LINE HOOKUP................................................................................................................................... 3
2.3 CABLE HOOKUP........................................................................................................................................ 3
2.4 GAS FLOW LIMITS..................................................................................................................................... 3
2.5 GAS FLOW VOLUME................................................................................................................................. 4
3.0 OPERATION................................................................................................................... 5
3.1 FIRMWARE VERSION............................................................................................................................... 5
3.2 LIMITS.......................................................................................................................................................... 5
3.3 PARAMETERS............................................................................................................................................ 5
3.4 BATTERY SPECIFICATIONS.................................................................................................................... 6
4.0 SETTING GAS FLOW CONTROL LIMITS................................................................... 7
4.1 DESCRIPTION............................................................................................................................................ 7
4.2 SETUP......................................................................................................................................................... 7
5.0 GAS FLOW SURGE "P" MEASUREMENT................................................................. 8
5.1 DESCRIPTION............................................................................................................................................ 8
6.0 GAS FLOW USAGE "U" MEASUREMENT................................................................. 9
6.1 DESCRIPTION............................................................................................................................................ 9
6.2 SETUP......................................................................................................................................................... 9
7.0 GAS CYLINDER LOW VOLUME MEASUREMENT.................................................. 10
7.1 DESCRIPTION.......................................................................................................................................... 10
7.2 SETUP ....................................................................................................................................................... 10
8.0 GTFM CONNECTOR PIN ASSIGNMENT.................................................................. 11
8.1 AUX CONNECTOR................................................................................................................................... 11
8.2 RELAY CONNECTOR.............................................................................................................................. 11
9.0 CHANGING THE BATTERY ....................................................................................... 12
10.0 MODEL SPECIFICATIONS...................................................................................... 13
10.1 120 VAC PORTABLE GTFM IVSYSTEM P/N: A0A0032.................................................................. 13
10.2 240 VAC PORTABLE GTFM IVSYSTEM P/N: A0A0033.................................................................. 14
10.3 ADM IVGTFM IVSYSTEM P/N: A0A0064...................................................................................... 15
10.4 120 VAC IN-LINE GTFM IVSYSTEM P/N: A0A0036......................................................................... 16
10.5 240 VAC IN-LINE GTFM IVSYSTEM P/N: A0A0037......................................................................... 17

10.6 GTFM IVRELAY CABLE P/N: A3W0259............................................................................................ 18
10.7 GTFM IVAUX CABLE P/N: A3W0260................................................................................................. 19
10.8 GTFM IVENCLOSURE ASSEMBLY P/N: A3W0179......................................................................... 20
10.9 GTFM IVMOUNTING DIMENSIONS.................................................................................................. 22

1.0 Overview
1.1 System Requirements
The GTFM IVGas Turbine Flow Monitor, is designed to permit the user to
precisely measure the flow rates of the weld shielding gases. WARNING – DO NOT
USE WITH ANY FLAMMABLE GASES. The unit comes in both "portable" and "in-
line" models and is available in English or Metric versions. The portable version can
be used to check the gas flow rates directly at the welding torch. The unit is battery
powered, which allows it to be carried throughout the shop. This version is ideal for
use by maintenance personnel to correctly set and verify shielding gas flow rates at
the welding torch.
1.2 Benefits
The "in-line" version is designed to be permanently installed in a welding fixture to
continuously monitor the gas flow rate. When used in this manner the GTFM can
provide "sure-flow" gas testing by setting upper and lower control limits for the user
defined gas flow rates. An internal fault relay can be used to warn or interrupt the
welding process if an out-of-limits condition is detected.
1.3 Features
Some of the features contained in the unit are the capability to limit test, provide an
accumulated gas usage and peak flow rates as well as displaying on going gas flow
rates. The unit also provides an analog output voltage representing measured gas
flow rates.
1.4 Mechanical Specifications
Dimensions 3-1/4"W x 1-3/4"H x 5-3/8”L (85 mm W x 45 mm H x 127 mm L)
Weight 23 oz. (652 gm)
Pipe Fittings 3/8" NPT with 3/8" hose barb fittings
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1.5 Sensor Specifications
Measurement Range 5 - 255 CFH (2 - 120 LPM)
Display Resolution ±1 CFH (± 1 LPM)
Accuracy ±2 % of full-scale ±1 digit
Operating Pressure 50-PSI maximum (344 KPA)
Fault Relay Output: N.O. Dry Contact Closure
Relay Rating 120 vac @ 0.5 amps non-inductive, 24 vdc @ 1.0 amps non-
inductive
Analog Sensor Output: 0 - 2.55 vdc @ 10 ma.
Analog Scaling 0.01 vdc = 1 CFH (.01 V = 1 LPM)
Power Requirement 10 - 28 vdc @ 100 ma.
Operating Temperature 20° - 140° F (-7° - 60° C)
Battery Charger 120 vac 60 hz @ 300 ma (220 VAC 50 hz @ 300 ma)
Battery Life Approximately 2 hours with full charge
(English / Metric units of measurement available)
Note: Specifications subject to change without notification.
1.6 Models
The following models are covered in this document:
Part No. Description
A0A0032 120 VAC Portable GTFM IVSystem
A0A0033 240 VAC Portable GTFM IVSystem
A0A0064 ADM IVGTFM IVSystem
A0A0036 120 VAC In-Line GTFM IVSystem
A0A0037 240 VAC In-Line GTFM IVSystem
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2.0 Installation
2.1 Options
The GTFM can be used as a portable or in-line gas flow monitor. If the unit was
purchased as a portable monitor, it will be equipped with a rubber gas cone. The
cone is designed to fit standard torch gas cups and allows the GTFM to measure the
actual gas flow at the torch. To install, simply press the GTFM gas cone onto the
welding torch gas cup. Make sure that the cone is fitted snugly to the gas cup.
2.2 Gas Line Hookup
The GTFM may also be installed into the gas line and used to permanently monitor
the gas-flow rate. This model is supplied with barbed 3/8 ID hose fittings. The sensor
will accept any 3/8” NPT pipefitting. The user may hard plumb the sensor if desired.
DO NOT USE PIPE DOPE OR TEFLON TAPE ON THE PIPE FITTINGS. The
sensor should be located between the welding-gas solenoid and the torch. DO NOT
INSTALL THE SENSOR ON THE INLET SIDE OF THE GAS SOLENOID. If the
sensor is installed on the inlet pressure side of the gas solenoid, the maximum
operating pressure (50 psi) of the transducer may be exceeded.
WARNING: Do not over tighten fittings as it may twist the sensor out of position.
2.3 Cable Hookup
The GTFM provides an analog voltage, which will represent gas flow. This analog
voltage can be monitored by using the Auxiliary Cable and connecting the plug to the
"AUX" connector on the bottom panel. The output voltage will have the following
relationship:
2.55 volts = 255 cfh
or
.01 volts/cfh
The output impedance of this signal is 100 ohms and can source 2 milliamps of
current. The analog-interface cable can also be used to supply power to the GTFM.
The power requirement is (10 - 28) vdc @ 100 ma.
2.4 Gas Flow Limits
The GTFM can be used to test for High/Low gas flow limits. An internal fault relay
will be set (CLOSED) when the gas flow is within the programmed limits. The fault
relay can be interfaced to an external weld fixture controller.
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NOTE: THE FAULT RELAY WILL ONLY BE ACTIVE WHEN POWER IS SUPPLIED VIA
THE PLUG-IN TRANSFORMER OR AN EXTERNAL POWER SOURCE
CONNECTED TO "AUX" CONNECTOR.
2.5 Gas Flow Volume
The GTFM can also be used to monitor accumulated gas flow and to provide an
indication when the volume in a gas cylinder has reached a programmed minimum
limit. The GTFM will calculate the volume of gas used based on the measure flow
rate. If the user programs the initial volume in a cylinder, and the minimum volume
for safe operation, the GTFM will indicate when the estimate minimum volume has
been reached. The GTFM will flash a "G" on the display when the estimated cylinder
volume has decreased below the programmed minimum. Setting the starting volume
“V” to 0 disables the function.
NOTE: THE LOW GAS VOLUME FAULT WILL NOT ACTIVATE THE FAULT RELAY BUT
WILL INDICATE THE FAULT CONDITION BY FLASHING A "G" ON THE
DISPLAY SCREEN.
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3.0 Operation
3.1 Firmware Version
The GTFM is supplied with a plug-in the wall transformer, which powers the GTFM
and will also charge the optional internal battery. Plug the transformer into a suitable
ac receptacle, and connect the power cable into the "POWER" jack located on the
bottom panel of the GTFM. Turn the power switch on the front panel "ON".The LED
display will sequentially display the following power up message.
1
ST 2 ND 3 RD
GTFM V#.# 0
Where: #.# is the firmware version number
Activate the gas solenoid for the welding torch. The GTFM will now display the gas
flow rate in CFH (Cubic Feet per Hour).
3.2 Limits
To program the High/Low limits and test parameters press the "Mode" switch (left
most toggle switch) to the up ("SET") position. The first programmable parameter will
appear on the display. The letter displayed on the left most part of the display
indicates the selected parameter. To select the next parameter, press the toggle
switch to the up ("SET") position. To change any displayed value press the "MODE"
switch to the down ("PGM") position. Each pressing of the switch will increment the
value by 1. To auto increment the value hold the "MODE" switch in the down
("PGM") position for 1.5 seconds and the GTFM will auto increment the value.
Release the switch to terminate the auto increment function.
NOTE: PRESSING THE TOGGLE SWITCH DOWN WHILE VIEWING THE ACCUMULATED
VOLUME PARAMETER ("U"), WILL RESET THE VALUE TO 0.
3.3 Parameters
The following programmable parameters will be displayed with each successive
press of the "MODE" toggle switch to the up ("SET") position:
Low limit for gas flow testing (cfh/lpm)
High limit for gas flow testing (cfh/lpm)
H###
L###
Delaytimefromstart of gas flow to enable
testing of the high limit (.01 seconds)
D###
5

Test time that the flow must be continuously
T### out of limits before activating the fault relay
(0.01 seconds).
P### The peak gas flow value detected (cfh/lpm)
The peak gas flow value detected (cfh/lpm)
M### that when reached, will provide a low gas volume
fault indication (Flashing "G" on display).
(0 - 255 cubic ft/liters)
V### The current volume of gas in the cylinder.
(0 - 999 cubic ft/liters)
The total volume of gas used based
U### on actual gas flow rates and time.
(0 - 999 cubic ft/liters)
Where: ### is the current value for the selected parameter.
After displaying the last parameter, the GTFM will return to the normal display mode.
If a "MODE" switch function is not activated within 20 seconds, the GTFM will
automatically return to the normal display mode.
3.4 Battery Specifications
The portable GTFM is supplied with an internal, rechargeable battery. The battery
will operate the GTFM continuously for approximately 2 hours when fully charged.
The supplied plug-in the wall transformer will recharge the battery in approximately 8-
10 hours. The GTFM can be operated while charging the battery. When using the
GTFM in battery powered mode the display will automatically clear and a "." will be
displayed. This is used to conserve the battery when the GTFM is not measuring
actual gas flow. The low power mode will be activated after approximately 25
seconds of no gas flow readings. As soon as gas flow is detected the normal display
will return.
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