Brooks, Digital mfc's and mfm's – Brooks Instrument SLAMf Series User Manual
Page 51

4-3
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
Tables 4-1 and 4-2 list possible malfunctions which may be encountered
during bench troubleshooting.
For Analog Controller Models Only: Apply +5 Vdc to the valve override pin
(pin 12) and verify that the output exceeds 100%. Connect the valve
override pin to the power supply common (pin 9) and verify that the output
signal falls below 2%.
4-1-2 Cleaning Procedures
When deposition makes it necessary to clean the Brooks SLAMf Digital
Series Mass Flow Controller or Mass Flow Meter, use the following
procedures:
1. Remove the unit from the system.
2. Purge with dry nitrogen gas, which removes virtually all particulate
matter from the device. Should contamination persist, subject all
wetted
1
components to ultrasonic cleaning. Following this, purge the
device thoroughly with dry nitrogen gas once again.
3. If the sensor is contaminated, remove the sensor and use a haemostat
or tweezers to push a 0.007" diameter piano wire through the
flow-sensor tube to remove any contamination (end closest to the
control valve). The sensor tube can then be flushed with a solvent that
leaves no residue. This can be accomplished conveniently using a
hypodermic needle filled with solvent.
NOTE: Do not soak the sensor assembly in a cleaning solvent. If solvent
seeps into the sensor assembly, it will likely damage or significantly alter
the sensor's operating characteristics.
Figure 4-1 Bench Troubleshooting Circuit
1
Wetted components include the body, laminar-flow element, and all valve components including the orifice, process adapters and inlet
filters (if so equipped).