Brooks Instrument QMBM - Manual (Page 46)

Section 4 Maintenance
4-6
Installation and Operation Manual
X-CM-QmB-eng
Part Number: 541B029AAG
June, 2011
QmB Series IP40, IP66, IP66XP
4. Provide an electrical signal to the Quantim representing a setpoint
of 50% of full scale flow and adjust the inlet and outlet pressures to
calibration conditions.
5. Verify that the electrical output signal reaches 100% of flow. For
MFC applications vary the setpoint over the 1% to 100% range and
verify that the output signal matches the setpoint.
a. If possible, connect a flow measurement device (such as a
rotometer) to the Quantim outlet to monitor the actual flow
behavior.
6. If the Quantim is functioning correctly, the problem may lie
elsewhere in the flow system. Re-verify the installation as well as the
upstream/downstream fluid system configuration.
7. Please contact Brooks Instrument for further assistance in
troubleshooting. Refer to the back cover of this manual for contact
information.
PRESSURE
GAUGE
PRESSURE
GAUGE
FLUID
SUPPLY
PRESSURE PRESSURE
REGULATOR
QmB
FLOW
OPTIONAL
MEASURING MEASURING
DEVICE
SHUT-OFF
VALVE
SHUT-OFF SHUT-OFF
VALVE OR
BACK
PRESSURE
REGULATOR
Brooks Instrument
TM
PRECISION MASS FLOW
Figure 4-1 Bench Troubleshooting Circuit