MRK-D-0048 V4
Aeroqual Dust Sentry / AQS User Guide
Page | 53
2. Adjust the zero offset on the O
x
and O
3
module is so that O
x
and O
3
read zero.
(Confirm NO
2
reads zero but do not adjust calibration settings on the NO
2
channel).
3. Deliver 0.1 ppm NO
2
gas from the calibrator.
4. Adjust
O
x
gain
so the O
x
reads 0.1 ppm.
NOTE: The NO
2
module should be reading 0.1 ppm during the 0.1 ppm Ox span calibration. The NO
2
may read slightly less than 0.1, this is normal, do not adjust the NO
2
gain.
5. Deliver zero air for 10 minutes to allow the sensors to return to baseline.
6. Then deliver 0.1 ppm Ozone.
7. Adjust O
3
gain so that the O
3
module reads 0.1. The Ox module will be showing a response
towards Ozone during the O
3
calibration, this is expected.
If the NO
2
shows a response during the Ozone calibration then a new
a
value must be
calculated according to equation 3 and applied as shown in Figure 5-4.
[NO
2
] = [Ox]
– [aO3] = 0.00
a = [Ox] / [O
3
]
span concentration
Set the
a
value in the Manual Entry dialogue in the Service and Calibration App (
Figure 5-4
).
Check the NO
2
reads zero under these conditions.
8. Deliver Zero air for 10 mins to purge the gas lines before returning to sampling ambient air.
7.1.6.1
Calibration pre-checks:
You will need to record a range of details as part of the calibration process. Use the Calibration
Record document in section 12.3.
The list of record capture tables are listed below:
Table
Details to record
1
Monitor, customer, and calibration technician details
2
Calibration equipment used
3
Calibration gas details
4
Changes to the local surroundings which may have an impact on the measurements
5
Monitor pre check results
Before you open the door
Monitor pre-checks
5.1
Put the monitor into Service Mode.
5.2
Check that the gas inlet is secure, if yes pass
5.3
Check that the particle inlet is secure, if yes pass
5.4
Check that door locks are operational, if yes pass
5.5
Measure and record the gas inlet flow rate
5.6
Record the previously measured flow rate, this value should be recorded in the monitor
journal.
Open the door
NOTE: To keep the sensor readings stable, minimise the time the door is open.
5.7
Replace the inlet filters
5.8
Measure and record the inlet flow rate again after changing the filter.
If the inlet flow has changed compared to step 5.6,(but less than ± 20 %) since last time
it was measured then check the gas connections for obvious leaks, then use the flow
adjustment valve to correct the flow.
If adjustment was unsuccessful then go to Step 6.
If the inlet flow has changed (more than ± 20 %) since last time it was measured (step
5.6) then go to Step 6.
Close the door
5.9
Record the final total flow.