Brooks Instrument SLA5800 Series - Manual (Page 51)

4-5
Brooks ® Digital MFC's & MFM's
Section 4 Maintenance &
Troubleshooting
Installation and Operation Manual
X-TMF-SLA5800-MFC-eng
Part Number: 541B027AAG
April, 2013
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.
This section contains suggestions to help diagnose simple MFC/MFM
related problems in the gas distribution system and answers commonly
asked questions.
Bench Troubleshooting
1. Establish a proper connection between the Brooks 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.
Figure 4-1 Bench Troubleshooting Circuit