Brooks Instrument GF126 - Manual (Page 49)

4-5
GF100 Series
Installation and Operation Manual
X-TMF-GF100-Series-MFC-eng
Part Number: 541B137AAG
March, 2013 Section 4 Maintenance & Troubleshooting
Symptoms & Possible Causes Corrective Action
4. No gas flow above some set-point.
NOTE: When the setpoint is
increased beyond this point,
the GF100 Series signal remains at
some value lower than the set-point.
Is the gas inlet/outlet differential Verify that the pressure is correct for
pressure sufficient? the gas and range. If required, adjust
regulator to achieve proper pressure
NOTE: If the pressure reading is too low,
the valve voltage to the GF100 Series
will be at its maximum output. This condition
will cause internal GF valve heating and
inability to properly reach desired flow setpoints.
Is the GF100 Series calibrated for the
Check GF100 Series side label. Run a flow check to verify.
gas flow? If flow is incorrect, replace the GF100 Series with a unit that
is calibrated properly.
5. No gas flow below some set-point.
NOTE: When the setpoint is
decreased below this point, the
GF100 Series signal remains at
some value higher than the
setpoint.
Is the gas inlet/outlet differential Verify that the pressure is correct for
pressure too high, or above published this gas and range. If required, adjust
setpoints? regulator to achieve proper pressure
NOTE: If the differential pressure reading.
is too high, voltage to the
GF100 Series will be at its maximum
value when the setpoint is
decreased below the point
where flow decreases.
Is the GF100 Series leaking?
Check for contamination. Test the GF100 Series
for leak integrity. Replace the Unit
GF100 Series if leakage is detected.
6. Gas flow, or GF100 Series pressure
reading oscillates.
Is the GF100 Series calibrated for the
Check the GF100 Series side can label. Run
gas flowing? a flow check to verify. If flow is incorrect,
replace the GF100 Series.
Is there too much gas pressure Verify that the pressure is correct for
across the GF100 Series? this gas and range. If required, adjust
regulator to achieve proper pressure
reading.
Table 4-2 GF100 Series Troubleshooting Guide (Continued)