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MRK-D-0048 V4
Aeroqual Dust Sentry / AQS User Guide
Page | 55
If the values are within the accepted range, listed in Table 7 column 7.2.3 (b) then no offset
adjustment is required, write
pass
in column 7.2.7. Move on to next module and
go to Step
7.2.1.
7.2.4
If the stabilised value is outside the acceptable range then an offset adjustment is required.
Calculate and record the new offset using Equation 4.
New offset = Current (AQM gas reading / Gain)
You can use the calibration app “Recommend” button (Figure 5-3), this will perform the calculation but
you must accept this offset by pushing the “Apply” button, this will upload the new offset.
7.2.5
If the new calculated offset is within the acceptable range listed in Table 7 column 7.2.4 (b)
then upload the new offset.
If the required offset is outside the recommend limits listed in Table 7 do not upload the offset,
write
fail
in column 7.2.7. Move on to next module and
go back to Step 7.2.1.
7.2.6
After 2 or 3 minutes record the readings after the new offset has been uploaded. Confirm the
readings are within acceptable limits.
If yes then
pass
, if no then
fail
. Move on to next module and
go to Step 7.2.1.
Span Calibration
Table
Details to record
8
Span calibration results
Span Calibration is performed separately in sequence for each gas module. Span calibration should
only be performed on modules that have been successfully Zero calibrated.
It is recommended to leave any failed modules running in the monitor throughout the zero and span
calibration process. After the calibration is complete on the remaining modules, then the door to the
monitor can be opened and the failed modules can be removed for inspection.
The NO
2
calibration, (
a
adjustment) should be performed at the appropriate step during the Ozone
span gas delivery, Step 8.1.16
NOTE: The order in which modules should be span calibrated is very important, see section 5.3
1) O
x gain
(using NO
2
calibration gas),
2) O
3 gain
(using O
3
calibration gas),
3) NO
2
a
value
(using O
3
calibration gas),
4) PID
gain
(using Isobutylene calibration gas)
NO
2
does not have a zero or gain adjustment applied.
8.1.1 Start here for each module. Once all modules have been span calibrated go to Step 9.
Record all initial gains in Table 8 Column 8.1.1
Record the initial NO
2
a
value in Table 8 Column 8.1.2
8.1.2
Start the NO
2
calibration gas flowing at your chosen span point, Aeroqual recommends 0.1
ppm. Make sure there is excess flow out from the tee at the monitor inlet as shown in Figure
5-6.
8.1.3
Record the span gas concentration. In Table 8 column 8.1.3.
8.1.4
Wait for the O
x
module values to stabilise to the NO
2
span gas, this means the readings are
within the acceptable noise limits listed in Table 8 Column 8.1.5 (c).
If the values have not stabilised then write
fail
in the column 8.1.10. Move on to next module
and
go to Step 8.1.1.
NOTE: If the O
x
module fails calibration then the NO
2
measurement cannot be used. The O
3
module
can calibrated even if the O
x
module fails calibration.
8.1.5
Record the stabilised O
x
values in the calibration form Table 8 Column 8.1.5 from the 10
minute average
If the values are stable and within the accepted range listed in Table 8 Column 8.1.5 (b) then
write
pass
in column 8.1.10. Move on to next module and
go to Step 8.1.1.