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Model 200E Instruction Manual EPA Protocol Calibration
Evidence of good quality data includes documentation of the quality control checks and the
independent audits of the measurement process by recording data on specific forms or on a
quality control chart and by using materials, instruments, and measurement procedures
that can be traced to appropriate standards of reference.
To establish traceability, data must be obtained routinely by repeated measurements of
standard reference samples (primary, secondary, and/or working standards). More specifically,
working calibration standards must be traceable to standards of higher accuracy.
8.8.1. Certification Procedures of Working Standards
This procedure requires the use of calibrated NO gas traceable to an NIST-SRM and the gas
phase titration calibration procedure (Section 8.2) to calibrate the NO, NO
X
, and NO
2
responses of the analyzer. Also the efficiency of the analyzer’s NO
2
converter must be
determined (Section 7.1.7).
Generate several NO concentrations by diluting the NO working standard. Use the nominal
NO cylinder concentration, [NO]
NOM
, to calculate the diluted concentrations. Plot the
analyzer NO response (in ppm) versus the nominal diluted NO concentration and determine
the slope, S
NOM
. Calculate the NO concentration of the working standard [NO]
STD
from:
[NO]
STD
= [NO]
NOM
x S
NOM
A more detailed procedure is presented in Reference 1.
8.8.1.1. Other Methods of Establishing Traceability
Methods of establishing traceability are:
• Using a NO working standard traced to NIST NO
2
standard
• Using a NO
2
working standard traced to NIST NO
2
standard
• Using a NO
2
working standard traced to NIST NO standard
NOTE
If the NO
2
impurity in the NO cylinder, [NO
2
]
imp
is greater than the 1 ppm value
allowed in the calibration procedure, check that the NO delivery system is not the
source of contamination before discarding the NO standard.
For further information on calibration by GPT and NO
2
permeation devices, refer to
part 50 of Chapter 1, Title 40 CFR, Appendix F Reference 13 of that Appendix.
8.9. References
1. Environmental Protection Agency, Title 40, Code of Federal Regulations, Part 50,
Appendix F, Measurement Principle and Calibration Procedure for the Measurement
of Nitrogen Dioxide in the Atmosphere (Gas Phase Chemiluminescence), Federal
Register, 41 (232), 52688-52692, December 1976 (as amended at 48 FR 2529,
Jan 20, 1983).
2. Ellis, Elizabeth C. Technical Assistance Document for the Chemiluminescence
Measurement of Nitrogen Dioxide, U.S. Environmental Protection Agency, Research
044100102 Rev A 139