G. Calibration and Zero Checks
Model AQSync Air Quality Monitoring Station Manual Rev. A-1
41
recommended to field-check the zero every 6 months. To carry
out a zero check, disconnect the top from the PM inlet and attach
a filter (provided with your AQSync) as shown.
N
ote that this is essentially a “leak test” for the PM instrument,
and no calibration parameters will be adjusted. Rather, the
expected values here are all zeroes for PM 1, 2.5, and 10. If the
values are not zero, there is a leak somewhere. Most likely, the
inlet tube is not properly inserted through the internal o-ring
leading into the PM instrument. Adjust and re-seat the sampling
inlet tube until the values show zero. If the leak persists, some
other source of a leak, or a malfunction of the Met One
instrument, is indicated.
G.2.4
CO Sensor
The CO sensor is an Alphasense Model CO-A4. For the highest
data quality, quarterly zeroing is recommended. Zeroing requires a stream of air that is
both CO-free and humidified.
G.2.5
NO
2
/NO/NOx Module
The electronic zeros for NO
2
and NO are tested by introducing NO
x
-free air to the
analyzer. The NO
x
-free air can be generated from either (1) passing ambient air through
a NO
x
scrubber or (2) using zero grade air from a compressed cylinder or zero air
generator via a user-provided valve system and an overflow tee. Please see the NOx
module user manual linked in Appendix 1 for more information.
G.2.6
Weather Transmitter
The weather transmitter is a R.M. Young Company ResponseONE Model 92000. Per
the manufacturers’ information, the weather transmitter does not have a protocol for
routine zeroing or calibration.
