PureAire Monitoring Systems, Inc.
40
Press
ENTER
to accept this value. The digital display will revert back to
Set Sensor
Span.
Press the joystick to the left to revert back to the
Sensor Adjustment
menu.
6.2.1 Sensor Verification to Nitrogen
PureAire recommends challenging the O
2
monitor with nitrogen every 6 to 12
months. The sensor protector has a ¼” male tube fitting designed for connecting
sample tubing from a Nitrogen cylinder. Expose the O
2
cell to N
2
at a flow rate
of 500 cc/min. The reading will drop off to 1% or below in less than one minute
when the O
2
sensor is exposed to pure N
2
. The system will recover to 20.9%
when the nitrogen is removed.
NOTE: The Sensor Protector has four air relief holes that will prevent the
complete exposure of nitrogen to the oxygen sensor. To see a true zero
oxygen level, the entire Air Check
O
2
monitor needs be completely
immersed into a zero oxygen environment. Covering the holes will help to
prevent dilution of the span gas to ambient air.
6.2.2 Sensor Verification to a known concentration of Oxygen
When testing the O
2
monitor to a known concentration of oxygen, the sensor inlet has a
¼” compression tube fitting designed for connecting the sample tubing. You can
connect ¼” OD sample tubing from a cylinder filled with Zero Grade air directly to the
sensor protector and expose the O
2
cell directly at a flow rate of 500 cc/min.
Expose the monitor for 1 minute and then adjust the reading to 20.9% when using Zero
Grade air. Turn off the regulator and remove the Zero grade air from the monitor. The
final reading should be within
±
0.3% of the span gas concentration.
To see the exact span gas concentration the entire Air Check O
2
monitor needs to
be completely immersed into a the span gas environment.
093
20.9%
..Set Sensor Span..
20.9%
…Sensor adjustment..
20.9%
