48
MODEL CLARITY II
SECTION 7.0
MAINTENANCE
7.2 SENSOR
7.2.1 Cleaning the sensor
Clean the sensor by rinsing it with water followed by wiping with a soft tissue. If water is inadequate, wash with a
mild detergent solution followed by thorough rinsing with water.
Do not scratch the lamp or photodiode win-
dows.
If mineral scale is present, use a dilute acid solution applied with a cotton swab to clean away the deposit. Rinse
thoroughly with water.
Do not use abrasive cleaners or solvents.
7.2.2 Replacing the lamp/LED board
The USEPA-compliant sensor uses a tungsten filament lamp (PN 1-0901-0004-EPA) as the light source. The
lamp has an expected life of about one year. The ISO-compliant version uses an infrared LED (PN 1-0901-
0005-ISO). Its expected life is five years. The Solu Comp II analyzer continuously monitors the source inten-
sity and corrects for changes in source intensity caused by age. When the source intensity becomes too low,
the analyzer warns the user. The user should replace the lamp as soon as possible.
To replace the lamp/LED board…
1.
Turn off power to the analyzer.
2.
Remove the sensor from the measuring chamber
and disconnect the cable.
NOTE
If you have a dual input analyzer, you can reapply
power at this point. The initial reading from the
other sensor will be momentarily zero. After about
60 seconds the reading will reach its final value.
3.
Using a small Phillips screwdriver, remove the two
screws holding the top flange of the sensor to the
body.
4.
Using a slight back and forth twisting motion
careful-
ly
pull the flange from the sensor body. You are
pulling against a single O-ring seal. Don’t pull too
hard.
5.
Using your thumb and forefinger, remove the
lamp/LED circuit board from the sensor.
6.
Insert the replacement board in the sensor and push
the socket on the replacement board into the mating
pins in the sensor.
7.
Place the desiccant package in the sensor body.
8.
Orient the flange so that the screw holes line up with
the holes in the sensor body. Push the flange back
on the sensor body and replace the screws. Don’t let
wires push on lamp board. It may be necessary to
turn the flange a small amount until the holes line up.
FIGURE 7-3. Replacing the Lamp/LED Board
step 4
step 5
step 6
CAUTION
BEFORE REMOVING THE SENSOR, be
absolutely certain the process pressure is
reduced to 0 psig and the process temper-
ature is at a safe level.
WARNING!
Explosion hazard. Do not disconnect equipment when a
flammable or combustible atmosphere is present.