Det-Tronics PW9200x Pathwatch IR Gas Detection System - Manual (Page 21)

WINDOWS
Interior windows are reached by removal of the trans-
mitter and receiver window assemblies. Clean as
described in “Exterior optical cleaning” procedure
above.
LENS, SYNC PICKOFF AND OPTICAL FILTERS
1. Remove the motor and filterwheel following
“Replacement of Filterwheel Motor” procedure.
2. The lens is located in the center of the receiver
baseplate. Using clean cotton swabs and alco-
hol, clean both sides of the lens. Finish with clean
optical tissue.
3. The sync pickoff is located at the center of the
rear panel p.c. board on the inside of the motor-
box. The optical surfaces are located on the
inside of the U-shaped device. Using clean cot-
ton swabs and alcohol, clean both optical sur-
faces of the sync pickoff. Remove any excess
alcohol and completely dry the surfaces with
clean, dry cotton swabs.
4. The optical filters are located in the filterwheel,
which is attached to the motor shaft. Clean both
sides of each filter using clean cotton swabs and
alcohol. Finish with clean optical tissue.
REPLACEMENT OF FILTERWHEEL MOTOR
(12 Month Interval)
It is recommended that this procedure be performed
in a lab environment. (See ACCESS TO INTERNAL
COMPONENTS.) Cleaning of interior optical compo-
nents should be done after the filterwheel motor is
removed.
1. The receiver housing cover and internal compo-
nents should be placed so that the open side of
the motorbox faces the technician. The assembly
should be securely propped during this proce-
dure to avoid damage to the internal components.
2. Disconnect motor connectors.
3. While holding the motor still, remove the four 6-32
sockethead screws on the front panel that attach
the motor and standoffs to the front panel.
4. Avoiding contact with the sync pickoff on the rear
panel p.c. board, carefully slide the motor and
attached filterwheel out of the motorbox. Viewing
ports have been provided on each side of the
motorbox to permit visual inspection of the posi-
tion of the filterwheel relative to the sync pickoff.
5. Remove the nut that holds the hub to the filter-
wheel and detach the filterwheel from the hub.
DO NOT TOUCH filters with bare hands.
6. Remove the nut from the replacement motor hub
and slide the filterwheel onto the replacement
motor shaft. Make sure that the side of the filter-
wheel with the filter retaining rings/fan blades is
facing toward the body of the motor. Replace the
nut, using low strength thread locking compound
on the threads of the hub. Make sure the com-
pound is thoroughly dried before rotating the fil-
terwheel.
7. Replace the motor/filterwheel assembly ensuring
that the filterwheel edge is straddled by the sync
pickoff. Check that the filterwheel does not come
into contact with the sync pickoff during rotation.
8. Replace the four sockethead screws that hold the
motor to the back of the instrument front panel.
Reconnect motor connectors.
REPLACEMENT OF TRANSMITTER LAMP
(Variable Interval)
The 15 watt lamp used in the PW9200 should be
replaced at a 24 month interval.
WARNING
Do not inspect the transmitter while the lamp is
operating. To avoid possible eye damage, dis-
connect instrument power before checking.
To replace the transmitter lamp, use the following pro-
cedure:
1. Disconnect all power to the instrument.
2. As an additional precaution, disconnect power
wires at the junction box.
3. Remove the window assembly from the transmit-
ter housing by rotating counterclockwise (CCW).
DO NOT TOUCH the window with bare hands.
4. Move the window assembly to a safe place, being
careful not to scratch the window.
5. Remove the old lamp by pulling it out of the lam-
pholder. DO NOT TOUCH the transmitter reflec-
tor with bare hands.
6. Insert the new lamp by pushing it into the lam-
pholder, aligning the pins and holes in the lamp
socket and gently wiggling until it is held firmly by
the two clamps. Replacement lamps are avail-
able from the factory. (See “Recommended
Spare Parts List”.)
19 95-8400