Honeywell SPM, Technical Handbook

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SPM Single Point Monitor
SPM Technical Handbook 5-7
Note:
Should there be a loss of enclosure pressure,
the safety interlock switch will disconnect
power to the instrument. Before restoring
pressure to the enclosure, shut off main power
via explosion proof switch (56). Purge and
restart the instrument as instructed in steps 9
through 11.
5.2.8 Z-Purge Troubleshooting
Carefully follow all of the steps of the installation proce-
dure. The SPM should be fully operational. If, however,
after completing the steps, the instrument is not acti-
vated, make sure:
1. The electrical power connection (1) is good.
2. The main power switch (8) on the SPM is on
and that the explosion proof power switch (56)
is turned to the “on” position.
3. Air pressure within the enclosure is high enough
to activate the pressure switch.
If, after trying all of these steps, the instrument still does
not activate, insert key into override switch (55) and turn
clockwise to activate SPM. If the instrument activates,
you may have a faulty pressure switch. For more
information, contact Honeywell Analytics Service.
Warning
For continued protection against risk of fire,
replace the instrument (front panel) fuse with a 5
x 20 mm, 250-volt, slo-blo fuse only. Refer to front
panel fuse label for proper fuse type and rating.
5.3 Duty Cycle Option
The duty cycle option switches SPM operation from
continuous monitoring to intermittent sampling. The
option conserves Chemcassette
®
usage in applications
which have a background level of the target gas.
5.3.1 Duty Cycle Intervals
The duty cycle option allows sampling intervals in
half-minute increments from one-half to 17 minutes
during which the SPM will perform one sample cycle.
For example, a selected duty cycle of five minutes will
cause the SPM to perform one sample period every
five minutes.
During the non-monitoring period, the sample pump is
shut off until about 60 seconds before the next moni-
toring period. This ensures that a fresh sample will be
analyzed. If the sample time for the target gas is greater
than or equal to the duty cycle interval, the instrument
will monitor continuously.
If the Duty Cycle period is set to less than 1-1/2 minutes,
the SPM will continue to draw a sample. If the Duty Cycle
is set to 1-1/2 minutes or greater, then the SPM will shut
the sample pump off when the current monitoring period
is complete, but will turn the pump on about 60 seconds
before the SPM is to do a monitoring cycle.
5.3.2 Setting the Duty Cycle
Set the SPM duty cycle as follows:
1. Open the tape load lever (18) to put the SPM in
load mode.
2. Press alarm reset (11) and hold in for two
seconds.
3. The digital display (19) will flash (XX.X MIN)
which is the current duty cycle setting.
4. Press the alarm reset (11) to increase the duty