PureAire Monitoring Systems, Inc.
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5.4.4 Gas Prepration
CAUTION: Be sure to observe all safety guidelines when generating and using calibration gases.
NOTE:
Insure that the span gas is within certification period
NOTE:
When using cylinder span gas, gas must be a mixture of the target gas blended with air.
1.
Connect the Demand Flow regulator to the span gas cylinder
2.
Connect ¼” flexible tubing to the output of the regulator
5.4.5 Span Calibration
To access the span function, while in the Sensor Adjustment Menu, push the joystick right until the
”Set Sensor Span” menu appears. Push the joystick to the right to display the span menu.
3.
Connect the waste bag to the exhaust and open the valve on the waste bag and connect the system exhaust tubing to
the gas waste tedlar bag. Inspect the flow rate to confirm flow is not blocked.
4.
Connect the ¼” flexible tubing from the regulator to the inlet of the particulate filter Expose the methyl bromide
monitor to span gas for three (3) minutes. Adjust the display reading to the span gas by pushing the joystick up or
down to set the concentration value on the PPM display.
5.
Press
ENTER
to accept the calibration value.
6.
After calibration, disconnect the span gas from the monitor and permit the digital display to return to zero.
NOTE:
The Air Check Methyl Bromide monitor has an internal pyrolizer that converts the gas to bromine.
Typical fall times can range from 1 to 4 minutes depending on the exposure concentration. The higher
the concentration, the longer the fall time to zero.
7.
Return the system to the monitoring mode by pushing the joystick to the left until the “CH
3
Br ” appears on the top line
of the display. Reattach the front cover to the sampling system.
Note: The remaining span gas and collected waste gas should be properly exhausted.
114
0.0 PPM
139
5.0 ppm
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