Brooks Instrument Mfi Series - Manual (Page 40)

4-2
Brooks ® Mf Series
Section 4 Maintenance &
Troubleshooting
Installation and Operation Manual
X-TMF-Mfi-Mfx-MFC-eng
Part Number: 541B074AAG
August, 2009
4-2 Troubleshooting
When installing the controller, care should be taken that no
foreign materials enter the inlet or outlet of the instrument. Do not
remove the protective end caps until time of installation.
CAUTION
A. System Checks
The Mf Series instrument is generally used as a component in gas
handling systems which can be quite complex. This can make the task of
isolating a malfunction in the system a difficult one. An incorrectly
diagnosed malfunction can cause many hours of unnecessary downtime. If
possible, make the following system checks before removing a suspected
defective mass flow controller for bench troubleshooting or return,
especially if the system is new:
1. Verify low resistance common connections and that the correct power
supply voltage and signals are reaching and leaving the controller.
2. Verify that the process gas connections have been correctly terminated
and leak checked.
3. If the mass flow controller appears to be functioning but cannot achieve
setpoint, verify that sufficient inlet pressure and pressure drop are
available at the controller to provide the required flow.
4. Verify that all user selectable jumpers are in their desired positions.
Refer to Figure 3-5.
This product contains elastomers that are used to seal the process gas
and also to maintain a water tight and dust tight enclosure. Elastomers will
deteriorate and fail over time. The elastomer seals used in this product
have a maximum shelf life of five years, but severe service conditions may
shorten their lifetime. It is recommended that these process seals and
enviromental seals be inspected on a periodic basis and replaced anytime
the instrument is serviced and more often under severe conditions.
No other routine maintenance is required on the Model Mf Series other
than an occasional cleaning. If an in-line filter is used, the filtering element
should periodically be replaced or ultrasonically cleaned.