Filter
Top Products
REMOTE INTELLIGENT SENSOR - AREA MONITOR
Instruction 2772-0803 Page 4-1
Allow the Test data to cycle to the light level
value (track 1), HOLD the display and check that
the reading is near 220. RELEASE the track 1
display and then HOLD to check track 2. RELEASE
track 2 and again press the TEST Mode button to
return to the NORMAL mode.
The light fault will now be clear and the only
fault icon displayed should be the ‘door open’ symbol.
The ‘Flashing Bells’ and the numeric display will
remain until the end of the current four minute
sampling period (which commenced on the exit from
the TEST Mode).
4.4 ADJUSTING LIGHT LEVELS
RIS’s manufactured before April 1992 have
adjustment potentiometers under the tape cassette
which has to be removed before light levels can be
adjusted (see Supplement A ). This is not necessary
for the adjustment on units made after April ’92,
which is shown below:
Install the tape cassette if not present. Light
levels can only be adjusted with the cassette in-
stalled.
Enter the TEST Mode by pressing the red button
on the back of the door. Wait until the display has
cycled to show:
200 to 254
1
200 to 254
1
HOLD
Figure 4-1. Entering TEST Mode
This display status will be maintained for
5 minutes, or until the HOLD/RELEASE button is
pressed again.
Adjustment is made by means of the two potenti-
ometers that are located beside the tape head and
accessed through holes in the top plate. The light
level track 1 is adjusted by one, and track 2 by the
other. The potentiometer access holes in Figure 4-2.
Figure 4-2. Light Level Access Holes
4 MAINTENANCE AND
TROUBLESHOOTING
4.1 MAINTENANCE GENERAL
Under normal circumstances, recommended
routine maintenance consists of cleaning the
exterior of the enclosure, carrying out a check of
key parameters, and checking certain parts for
mechanical tightness. In addition, occasional
cleaning of the input path and optics block may be
required under adverse sampling conditions. Each
of these procedures is dealt with below.
NOTE: Most procedures require the unit
to be in TEST Mode. To enter TEST Mode
see Section 2.8.2.
4.2 VERIFYING THAT A GAS ALARM
WAS CAUSED BY GAS
In situations where the gas level monitored is
continuously zero and an alarm occurs, there may
be a tendency to assume that a system ‘fault’ is
responsible. Under these circumstances first
assume the alarm is genuine and take appropriate
action. The presence of gas is easily verified.
Put the system into the TEST Mode and
remove the cassette. Examine the tape in the gate
area and toward the take up spool. The presence of
a circular stain, or succession of stains, will verify
that gas has been sampled. The nature of the stains
will show the level of exposure as follows:
A faint stain, or succession of faint stains
increasing in density, suggests an initially low
concentration that is slowly increasing. As monitor-
ing continued, the stain density would diminish as
the contamination dispersed.
If the stains are intense, or become so quickly,
and then remain at the same high density, a
significant concentration has been sampled. (The
constant, dense stains, show that the system was
operating in the ‘time mode’ which only occurs at
higher concentrations. See Section 3.2.2).
4.3 CLEARING A SPURIOUS ALARM
If the tape gate is opened without putting the
system into the TEST Mode, an ‘alarm’ may be
initiated. It is also likely that a ‘light fault’ will
occur. To clear these conditions:
Open the door (if it had been closed), and enter
the TEST Mode. Ensure that there is a cassette
mounted and that tape is in the gate which should
be closed.
Press the HOLD/RELEASE
button on the front panel
firmly so that the display
shows: