Det-Tronics PIR9400 PointWatch Infrared Hydrocarbon Gas Detector User Manual

Page 22

95-8440

9.3

DISaSSEMBLy aND CLEaNING PROCEDURE
The PointWatch Detector should be inspected periodically

to ensure that its performance is not impaired by fouled

optics or by clogging of the filter or hydrophobic filter.

Inspection and/or periodic maintenance involves three

different areas of the detector.

iMPoRtant

Remove power before disconnecting and
removing the detector for maintenance.

NOTE

It is not necessary to remove the electronics
assembly from the detector base assembly in
order to clean the detector optics.

Filter/Baffle.

Perform a visual inspection of the

filter/baffle, checking for a variety of environmental

contaminants including nests of insects, spiders, etc.
Disassemble the PIR

9400

and clean as necessary.

hydrophobic Filter

(used on all aluminum and

select stainless steel models). While clogging of the

hydrophobic filter is rare in most installations, the flow of

gas through the filter can be inhibited by an accumulation

of extremely fine particles of airborne contaminants. To
inspect the hydrophobic filter, disassemble the PIR

9400

as described in this section. If the filter appears to be

fouled, replace it. As an alternate to a visual inspection of

the filter, the PointWatch Detector can be tested using the

PointWatch Wind Shield Calibration Bag, available from

Det-Tronics. The bag is slipped over the gas detector

and secured with a Velcro sealing strap. Gas is applied

to the detector through the gas inlet nozzle on the end of

the bag.

iMPoRtant

The hydrophobic filter should be replaced
whenever the mirror assembly and reflector tubes
are cleaned or replaced, or when the filter appears
fouled upon visual inspection.

Optics.

Cleaning of the optical surfaces is required only

if an optical fault is indicated (

1.0

mA current output

signal from the detector, or an “optics fault” message
on the Infiniti U

9500

or FlexVu UD

). This procedure is

most easily accomplished on a bench.

iMPoRtant

If the Model PIR

9400

Detector optics system

is disassembled,

calibration is required after

re-assembly.

Required materials: Clean, flat work surface, foam tipped

swabs (no cotton), isopropyl alcohol, screwdriver or hex

wrench.

Caution

The PointWatch Detector contains semiconductor
devices that are susceptible to damage by
electrostatic discharge. An electrostatic charge
can build up on the skin and discharge when
an object is touched. Therefore, use caution
when handling the device, taking care not to
touch electronic components or terminals. If the
electronics assembly is removed, it should be
placed in an anti-static bag or box while stored
or transported. A static safeguarded work area is
highly recommended (if available) for disassembly
and cleaning of the detector.

1. Disassemble the detector as shown in Figure

(aluminum) or Figure

(stainless steel). For

aluminum models, loosen the two captive screws

on the end of the detector and remove the filter

assemblies. For stainless steel models, loosen the

two captive screws on the end cap, then remove the

baffle and stainless steel collar.

2. Loosen the two captive screws on top of the mirror

assembly (Figure

) and slide the mirror assembly,

hydrophobic filter and reflector tubes away from

the electronics assembly and electronics mounting
cover. See Figure

(aluminum model) and Figure

(stainless steel model).

3. Disassemble the mirror assembly, reflector tubes

and hydrophobic filter as shown in Figure

and

Figure

. Do not remove the electronics mounting

cover.

4. Thoroughly douse the interior of the mirror assembly

as well as the foam tipped swab with isopropyl

alcohol. Use the swab to gently cleanse the surfaces

of the reflecting mirrors inside the mirror assembly.

After cleaning with the swab, flush out the mirror

assembly using a liberal amount of isopropyl alcohol.

Tip the mirror assembly with mirror openings

downward to remove accumulated isopropyl alcohol

and particle contaminants. Repeat the alcohol flush

to remove any remaining contaminants. Allow the

mirror assembly to air dry in a dust-free location.