Brooks Instrument 5850i - Manual (Page 32)

Brooks ® Model 5850i
4-4
Section 4 Maintenance Installation and Operation Manual
X-TMF-5850i-MFC-eng
Part Number: 541B108AAG
December, 2008
Table 4-2 Sensor Troubleshooting
4. Inspect the orifice for clogging by holding it in front of a light source
and looking for light through the bore. Clean by soaking in a suitable
non-residuous solvent and directing a stream of compressed dry
nitrogen through the bore.
5. Deposits of silicon dioxide may be removed by soaking the internal
parts in a solution of 5 parts hydrofluoric acid (HF) and 95 parts
water (H
2
O) followed by Freon TF.
6. Restrictor elements can be cleaned in an ultrasonic bath. Refer to
Section 4-7 for the correct restrictor to use.
7. Blow all parts dry with dry nitrogen and reassemble. Refer to Section
4-4b (assembly).
8. Purge the assembled controller with dry nitrogen.
9. Perform the calibration procedure in Section 3-4.
10. When the controller is re-installed in the system, the connections
should be leak-tested and the system should be purged with dry
nitrogen for 30 minutes prior to start-up to prevent the formation of
deposits.