MRK-D-0048 V4
Aeroqual Dust Sentry / AQS User Guide
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8.1.19 If your monitor contains a PID gas module, repeat steps 8.1.2 to 8.1.10 for PID.
Post-calibration checks
Table
Details to record
9
Post-calibration checks
Follow these post-calibration checks and record the results in Table 9 from the Calibration form in
Appendix 5.
9.1
Disconnect calibration equipment
9.2
Record the inlet flow rate
9.3
Replace the mesh inlet and cap
9.4
Lock door
9.5
Secure the site
9.6
Take monitor out of service mode and record the time in the form.
7.2 Particle Monitor calibration
Field calibration of monitor with Particle Monitor is typically not required.
However in some applications that have very high data quality objectives, field calibration may be
appropriate. Such applications may include:
Supplementary monitoring to a reference network (so inter-comparison to reference is
important)
Research studies that need to demonstrate traceability to another monitor
Consultancy projects that need to demonstrate traceability to another monitor
In summary, field calibration of Aeroqual PM monitors is recommended only when comparison
or traceability to reference PM monitors is an important factor in the monitoring project.
For all other applications the Aeroqual factory calibration is sufficient.
All PM monitors are calibrated at the factory against a standard aerosol (NIST traceable monodisperse
spheres). The factory calibration is traceable and results in good data quality when the monitor is
operated in accordance with Aeroqual’s servicing and maintenance procedures.
Factory servicing and calibration
Factory servicing includes cleaning and calibration of the PM module only. The PM module can be
removed from the monitor and returned to the factory. All Aeroqual PM Modules need to be returned to
the factory for service and calibration at the following intervals:
Dust Sentry Particle Monitor:
24 Months
Dust Sentry Particle Profiler
12 Months
NOTE: Field calibration is not a substitute for the specified factory service intervals above. Factory
servicing is essential maintenance, and c
hecks the ‘health’ of the internal components.
Field calibration
In order to perform a field calibration, your Aeroqual monitor must be located at the same site as a
Reference
PM monitor. This is called
‘Co-location’
and is widely performed in ambient air quality
monitoring to assess the performance of a new monitor. The two monitors are operated for a given
period of time, and their data are compared. An adjustment factor, called
‘K Factor’
is then calculated,
and applied to the Aeroqual monitor
Gain
. This corrects the data to the known reference monitor.
𝑲 𝑭𝒂𝒄𝒕𝒐𝒓 =
𝑨𝒗𝒆𝒓𝒂𝒈𝒆 𝑷𝑴 (𝑹𝒆𝒇𝒆𝒓𝒆𝒏𝒄𝒆)
𝑨𝒗𝒆𝒓𝒂𝒈𝒆 𝑷𝑴 (𝑨𝒆𝒓𝒐𝒒𝒖𝒂𝒍)
The K Factor is the applied to the monitor, using the Gain setting for each PM channel:
𝑵𝒆𝒘 𝑮𝒂𝒊𝒏 = 𝑶𝒍𝒅 𝑮𝒂𝒊𝒏 𝑿 𝑲 𝑭𝒂𝒄𝒕𝒐𝒓
You can also perform the adjustment in Microsoft excel or similar.
Field calibration is only as good as the reference data which is used
. Using poor quality reference
data for calibration will result in poor quality PM data from your Aeroqual monitor. Aeroqual recommends
that calibration only be carried out using high quality Reference PM Data. If you don’t have access to a