
Chapter Seven: Troubleshooting
How To Adjust the Valve Preload
39
7. Reconnect the cable from the controller/power supply and power up the unit.
Warning
Follow your corporate policy on handling toxic or hazardous
gases. Your corporate policy on handling these gases
supersedes the instructions in this manual. MKS assumes no
liability for the safe handling of such materials.
If appropriate, remove the MFC from the process tool and
make the adjustments using a surrogate gas.
8. Close all isolation valves in the system, both upstream and downstream of the MFC.
9. Zero the unit, following the instructions in How To Zero the Flow Controller, page 26.
10. Reconnect one electrical valve lead to a post on the PC Control board via a short clip
lead and the other via a DMM in series. (The leads are interchangeable.) Set the DMM
to measure current in the 10 to 100 mA range.
11. Open all upstream and downstream isolation valves in the system.
12. Hold the valve adjustment nut in place with a 13 mm crescent wrench and loosen the jam
nut using a flat 17 mm crescent wrench.
Refer to Figure 9 for the location of the adjustment nut and jam nut.
Jam Nut
(17 mm)
Adjustment
Nut (13 mm)
Valve Coil
Enclosure
Figure 9: Location of the Jam Nut and Adjustment Nut
13. Provide a set point input signal to the MFC of 0.25 Volts to represent 5% flow.
Содержание Mass-Flo 1479A
Страница 3: ...119474 P1 Rev B 10 97 MKS Type 1479A Mass Flo Controller ...
Страница 8: ...Table of Contents vi ...
Страница 10: ...List of Figures and Tables viii ...
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Страница 40: ...The Optional Input Chapter Four Operation 30 This page intentionally left blank ...
Страница 44: ...Zero Adjustment Chapter Six Maintenance 34 This page intentionally left blank ...
Страница 56: ...Physical Specifications Appendix A Product Specifications 46 This page intentionally left blank ...
Страница 70: ...Model Code Appendix D Model Code 60 This page intentionally left blank ...
Страница 72: ...Index 62 T Troubleshooting 35 U Unpacking 9 checklist 10 opening 9 V Valve override 28 Z Zero 26 ...