Teledyne Advanced Pollution Instrumentation | Model 633 Aethalometer® Black Carbon Monitor User Manual |
5.5 Manual stability test
Stability test is conducted without flow to determine the performance of the light source – detector pair. In the Operation/General tab select the desired timebase and click “Stability” button to start the test. Stability test is marked by status 1024. During the test BC values will be calculated assuming there is 5 LPM air flow. Manually stop the test when the desired test duration is complete.
Interpretation of the results:
-Average BC values should be close to zero if the Aethalometer is warmed up (was measuring for a few hours just before conducting the test).
‐ Point to point variation of BC (PPBC) is calculated as an average absolute difference between the consecutive BC measurements. It depends on the timebase, tested channel and spot. For example at 1 s timebase PPBC61 = approx. 400 ng/m3.
5.5Manual clean air test
Clean air test is conducted using the built‐in filter to determine the performance of Aethalometer under the standard flow condition. In the Operation/General tab select the desired timebase and flow, then click “Clean air” button to start the test. Clean air test is marked by status 2048. Manually stop the test when the desired test duration is complete.
Interpretation of the results:
‐Average BC values should be close to zero if the Aethalometer is warmed up (was measuring for a few hours just before conducting the test). It is possible to observe a short transient due to filter compression.
‐Point to point variation of BC (PPBC) is calculated as an average absolute difference between the consecutive BC measurements. It depends on the selected timebase, flow and tested channel. For example PPBC61 = approx. 500 ng/m3 at 5 LPM and 1 s timebase.
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