PureAire Monitoring Systems, Inc.
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4.3 Routine Maintenance Schedule
Continuous gas detection systems depended upon to measure and detect hazardous gas leaks in the
workplace requires periodic maintenance to ensure proper operation. The frequency with which this
routine maintenance is required depends on the environment. The following table is intended to serve
as a general guideline for routine maintenance. The conditions in your particular application, as well as
your organization’s maintenance policies, will ultimately determine the best routine maintenance
schedule for your equipment. Routine Visual Checks
Items to check
Check for power and proper operation
Condition / status when
operating properly
Unit should be outputting a 17.4 mA signal when
the oxygen level is at 20.9%. The LCD digital
display should also indicate 20.9% 0
2
when the
oxygen is at ambient levels.
4.3.2 Recommended Routine Maintenance Schedule
Routine Visual Checks
Every 6 - 12 months
Sensor Verification with nitrogen
Every 6 - 12 months**
** The ambient oxygen level is 20.9%; therefore, under ambient conditions verification of the
Air
Check
O
2
monitor to 20.9% oxygen is constantly being performed. The O
2
monitor only requires
periodic testing with nitrogen to verify the cells response to low oxygen levels. See Section 5.5.10 for
how to make minor adjustments.
4.4 Loss of Power Indicator
In the event the
Air Check
O
2
monitor loses 24VDC power, the 4-20 mA analog output signal drops
to 0mA. The LCD display will also display a blank screen.
4.5 Alarm Reset
It the Air
Check
O
2
monitor is supplied with the optional alarm relays, whenever the monitors alarms
are activated, the built-in alarm relays, panel mounted LED’s and optional audio horn will also
activate. When the relay settings are non-latching, the alarm relays, LED’s and horn will automatically
reset. If the relay settings are latching, then a manual reset of the alarms are required. Resetting the
alarms can be performed through use of the joystick or through the use of the remote reset function.
Joystick – You must enter the password to enter the reset function. After the password is entered and
accepted, push the joystick in; (enter) to reset the alarms.
Remote Reset – See section1.2.7. The alarm relay board has a two-pin connector for wiring to a
remote switch. When connected to a switch, this remote reset will bypass the joystick and a password
will not be needed to reset the alarms.
NOTE
:
The oxygen levels must recover above the alarm thresholds before the horn can be
reset from the remote reset switch or joystick.
