MKS Stabil-Ion 370 Series, Instruction Manual, Page: 111 / 122

7 Service and Maintenance
7-7
Series 370 Stabil-Ion Instruction Manual - 370119
7.7 Cleaning Contaminated Convectron Gauges
The Convectron Gauge may be baked to 150
°
C nonoperating while under vacuum with the Connector
removed.
All materials have been chosen for ultra high vacuum service, corrosion resistance, and bakeability. The
envelope is type 304 stainless steel. All metallic joints in the envelope are TIG welded. No solder is used
within the envelope. The following materials are exposed to the vacuum: Type 304 stainless steel,
Carpenter Alloy 52, Kovar, Kapton, gold plated tungsten, borosilicate glass and Dow-Corning 9015
glass. The blue trim cover is rated at 150
°
C.
When the small sensor wire is contaminated with oil or other films, its emissivity or its diameter may be
appreciably altered and a change of calibration will result. Cleaning with trichloroethylene,
perchloroethylene, toluene, or acetone is possible but it must be done very carefully so as not to damage
the sensor.
Hold the gauge with the main body horizontal and the port projecting upward at an angle of 45
°
. Slowly
fill it with solvent using a standard wash bottle with the spout inserted in the port to where it touches the
screen. Let the solvent stand in the gauge for at least ten minutes.
Do not shake the gauge. Shaking the
gauge with liquid inside can damage the sensor wire. To drain the gauge, position it horizontally with
the port facing downward. Slightly warming the gauge will help dry the gauge. Then allow the gauge to
dry overnight with the port vertically downward and uncapped. Before reinstalling the gauge on the
system, be certain no solvent odor remains.
7.8 Troubleshooting the Electrometer Module
If the Electrometer fails to operate, check the LCD display on the electrometer module for the error
indications listed in Table 7-6.
The fumes from solvents such as trichloroethylene, perchlorethylene, toluene,
and acetone can be dangerous to health if inhaled. If used, use only in well-
ventilated area exhausted to the outdoors. Acetone and toluene are highly
flammable and should not be used near an open flame or energized
electrical equipment.
Table 7-6 Electrometer Troubleshooting.
Symptom Possible Cause
LCD display blank. Display intensity needs adjustment.
μ
p failure light blinks. Electrometer module faulty.
IG shuts down. Check cause of shutdown.
See Section 7.10 on page 7-9, Turnoff
History, for details.
IG displays 9.99 when
gauge turn ON is
attempted. Load the gauge module into the Controller
via the data port. (Section 4.3.2 on page 4-5.)
Figure 7-4 Electrometer Module, Top View
Showing
μ
P Failure LED