1. Calibration
Calibration of the analyzer establishes the relationship between actual pollutant concentration input and the analyzer response.
Should be carried out at the field monitoring site by allowing the analyzer to sample test atmospheres containing known pollutant concentrations.

2. Points should appear as “walkable stairsteps” on the electronic chart.
The calibration includes the zero concentration and five upscale concentrations spaced equally over the measurement scale range of the analyzer ( PPM).
Ozone or SO2 Calibrations:
Set internal zero/span
Generate 5 points
NOx Calibration:
Generate 5 points NO-NOx
Generate 5 points NO2
0.400 PPM (span)
0.300 PPM
0.200 PPM
0.100 PPM
0.065 PPM
0.000 PPM (zero)
Points should appear as “walkable stairsteps” on the electronic chart.

3. Example of a properly conducted and correctly documented ozone calibration.

4. Example of a properly conducted and correctly documented NOx calibration.

5. Recalibrations Should be performed after any of the following:
Unacceptable QC precision check
Unacceptable QA performance audit
An extended interruption in analyzer operation
Any repairs that might affect its calibration
Physical relocation of the analyzer  
Excessive zero or span drift
Any other indication of possible significant inaccuracy of the analyzer