
Chapter Seven: Troubleshooting
How To Adjust the Valve Preload
37
How To Adjust the Valve Preload
Caution
1. All valves are adjusted at the factory for proper leak integrity and
flow control response. Adjust the valve ONLY if the Troubleshooting
Chart, Table 6, page 35, recommends that you do so.
2. Only qualified individuals should perform the installation and any
user adjustments. They must comply with all the necessary ESD
and handling precautions while installing and adjusting the
instrument. Proper handling is essential when working with all
highly sensitive precision electronic instruments.
Note
Valve preload adjustment cannot be performed in situ because the
procedure involves disassembling the MFC. Perform this procedure on a
properly equipped workbench.
This procedure requires the following equipment:
•
Any special safety equipment necessary to handle the gas in use
•
3
/
32
” allen wrench for the enclosure retaining and bracket hold down screws
(4-40 socket head cap screws)
•
#1 Phillips screwdriver
•
13 mm open end wrench for the adjustment nut
•
Flat 17 mm open end wrench for the jam nut (a bicycle cone wrench works well)
•
Digital Multi Meter (DMM)
•
Gas supply (N
2
, Ar, or He) with a local shutoff valve and a 0 to 40 psi regulator
•
Suitable MFC controller/power supply with cables
•
Clip lead
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 ...
Страница 34: ...Control Valve Chapter Three Overview 24 This page intentionally left blank ...
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 ...