GE Optica, Operator'S Manual

Page: 101 / 150

Maintenance 7-1
January 2006
Minor Maintenance of
Sensor Optics
Periodically inspect and maintain the sensor optics as described in the
following paragraphs. These procedures can be performed at any time
but are only necessary when the
Service
indicator appears on the
status display, indicating that service is required.
Cleaning the Sensor Mirror
Under normal conditions, the system is self-checking and self-
balancing. However, there are occasions when particulate matter and
water-soluble contaminants reduce sensor mirror reflectance and
system accuracy (see
Contamination on page 3-11). When necessary,
use the procedure below to clean the sensor 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.
Moisten a cotton swab with a cleaning solution suitable for
mirrors, such as the cleaning solution in the GE Infrastructure
Sensing maintenance kit, or dilute methanol or alcohol. Clean the
mirror with a few light wipes. If the sensor has been exposed to
significant contamination, clean the other optical surfaces in the
sensor and the sensor cavity itself.
5. Replace the sensor cover.
6.
Return the switches to normal, initiate a PACER cycle, and
continue operation.