GE Optica, Operator'S Manual

Page: 105 / 150

Maintenance 7-5
January 2006
Replacing the Sensor
Mirror
Required equipment: torque driver, set to 20-30 inch-ounces of
torque. GE Infrastructure Sensing type TW-1 is recommended.
The kit supplied by the factory contains the replacement mirror, a
container of white thermal compound for proper heat transfer, and (in
some models) a mylar washer that is to be placed under the mirror.
1.
Deactivate the sensor cooler, using one of the following actions:
•
Turn the sensor power off, or
•
Place the sensor switch to heat, or
•
Disconnect the sensor cable
2.
Turn off the sample gas. Make sure the sensor cavity is
depressurized before continuing with the next step.
3.
Open the sensor by removing the sensor cover.
4. Unscrew and discard the old mirror, using a 3/16-inch (0.187) hex
socket.
5.
Use a toothpick or similar tool to place a small amount of thermal
compound in the hole supporting the mirror.
Caution!
Do not apply thermal compound to the mirror stem.
Do not use an amount large enough to leak out when
the mirror is tightened.
Do not allow any compound to get on the mirror
surface, as it is very difficult to remove completely.
6.
Carefully screw in the new mirror and tighten to the proper torque
as specified for the particular sensor.
7. Carefully clean the mirror surface, using a cotton swab and the
GE Infrastructure Sensing cleaning solution supplied with the
maintenance kit. Distilled alcohol or diluted alcohol is also
acceptable.
8.
Replace the cover and return the sensor to normal operation.
Under some circumstances, a new mirror may operate in a
somewhat unstable manner for the first hour or two.