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EPA Protocol Calibration
Model 400E Ozone Analyzer
Instruction Manual
186
P/N 04316 Rev: B
To ensure accurate measurements of the O
3
levels, the analyzer must be calibrated
at the time of installation and re-calibrated as necessary. (Section 12 of the Q.A.
Manual.
1 1
)
A general procedure for dynamically calibrating a O
3
analyzer can be found in 40
CFR 50 Appendix C. Calibration can be done by either diluting high concentration O
3
standards with Zero Air or using separate supplies of O
3
at known concentration.
Care must be exercised to ensure that the calibration system meets the guidelines
outlined in the revised Appendix D, 40 CFR 50.
1
Detailed calibration procedures are
also discussed in the Technical Assistance Document (TAD).
2
Dynamic multipoint
calibration of the M400E must be conducted by using either the UV photometric
calibration procedure or a certified transfer standard. The equipment (i.e. calibrator
and UV photometer) that is needed to carry out the calibration is commercially
available, or it can be assembled by the user.
Calibrations should be carried out at the field-monitoring site. The Analyzer should
be in operation for at least several hours (preferably overnight) before calibration.
During the calibration, the M400E should be in the CAL mode, and therefore sample
the test atmosphere through all components used during normal ambient sampling
and through as much of the ambient air inlet system as is practicable. If the
instrument will be used on more than one range, it should be calibrated separately
on each applicable range.
Details of documentation, forms and procedures should be maintained with each
analyzer and also in a central backup file as described in Section 12 of the Quality
Assurance Handbook.
Personnel, equipment, and reference materials used in conducting audits must be
independent from those normally used in calibrations and operations. Ozone audit
devices must be referenced to a primary UV photometer or one of the Standard
Reference Photometers maintained by NIST and the US EPA.