Brooks Instrument SLAMf Series - Manual (Page 50)

4-2
Section 4 Maintenance &
Troubleshooting Installation and Operation Manual
X-TMF-SLAMf-MFC-eng
Part Number: 541B032AAG
April, 2013
Brooks ® Digital MFC's and MFM's
This section contains suggestions to help diagnose simple MFC/MFM
related problems in the gas distribution system and answers commonly
asked questions.
4-1-1 System Checks
The Brooks SLAMf Digital Series Flowmeters and Controllers are generally
used as a component in gas handling systems, which can be complex in
nature. It can therefore be very difficult to isolate a malfunction in the
system. An inaccurately diagnosed malfunction can cause many hours of
unnecessary downtime. If possible, perform the following system checks
before removing a suspect Mass Flow Meter or Controller for bench
troubleshooting or return to the factory. (especially if the system is new):
1. Verify a low resistance common connection and that the correct power
supply voltage and signals are present of the connector of the Smart
TMF.
2. Verify that the process gas connections have been made correctly, and
that they have been tested for leaks.
3. If the Mass Flow Controller appears to be functioning but cannot
achieve Setpoint, verify that there is sufficient inlet pressure and
pressure drop at the controller to provide the required flow.
Bench Troubleshooting
1. Establish a proper connection between the Brooks SLAMf Digital Series
Mass Flow Meter or Controller (using Figure 4-1 as a reference) Switch
on the power and allow the instrument to warm-up for 45 minutes. In
case of a Controller model, adjust the Setpoint to zero. Do not connect
the device to a gas source yet. Observe the output signal and, if
necessary, perform the zero adjustment procedure (See Section 3-4
zeroing function). If the output signal does not zero properly, please
contact Brooks Instrument.
2. Connect the instrument to a source of the same gas used for it's
original calibration. Regulate the Setpoint to 100% flow and adjust the
inlet and outlet pressures to calibration conditions. Verify that the output
signal reaches its full scale value and stabilizes at that value. Vary the
command voltage over the 1 to 100% range and verify that the output
signal follows the Setpoint If possible, connect a flow measurement
device to monitor the actual flow behavior and verify the accuracy of the
mass flow instrument. If the mass instrument performs as described
above, then it is functioning correctly and the problem may lie
elsewhere.