Pfeiffer Vacuum ASM 390 Additional Installation, Operation And Maintenance Instructions page 23

Pirani gauge disassembly
2
2
3
3
4
6
6
5
4
1 Harness
2 Retainer screw
3 CHc screws
1. Disconnect the harness from the gauge.
2. Remove the retainer screw.
3. Screw the CHc screw into the center of the gauge (CHc screw in the maintenance kit supplied
with the detector).
4. Pull on the CHc screw to free the gauge.
Pirani gauge reassembly
1. Position the new gauge.
– When inserting the new gauge, do not bring the gauge filaments into contact with the vacuum
block.
2. Tighten the retainer screw.
3. Connect the harness to the gauge.
4. Make adjustments to the gauge (see chapter "Calibration of the internal Pirani gauge" in the Oper-
ating Instructions).
Tightness test after Pirani gauge maintenance
1. Put the detector into cycle.
2. Spray a light flow of helium 4 around the gauge.
– leak rate measured < 3 · 10
1
1
4 Gauge
5 Filaments
6 Vacuum block
-10 mbar·l/s (3 · 10
Service - Maintenance
-11 Pa·m 3 /s).
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