Environnement AF22e, Техническое руководство, Страница: 72 / 118

Environnement
S.A
AF22e
Duplication prohibited
JUNE 2016
3–38
3.5. CALIBRATION
IMPORTANT NOTICE:
Analyzer use, as an equivalent method for EPA reporting, requires periodic multipoint calibration and
subsequent zero/span checks as described below. All gases for calibration must be traceable to a
National Institute of Standards and Technology (NIST) reference.
3.5.1. OVERVIEW OF CALIBRATION AND CONCEPTS
To ensure the accuracy of performed measurements using the AF22e analyzer, the unit must be
regularly checked, calibrated and adjusted, following the user’s quality assurance plan.
–
Zero and span check :
This operation compares the analyzer response, for the zero air and span point, to the used gas
standards.
This check is used to measure the analyzer drift in time without modifying the « Span Coeff. ».
This check can be performed by using the internal zero air and the span gas.
Periodicity: generally 24 hours, in automatic cycle mode for the zero check.
–
2-point calibration:
This procedure is used for checking and correcting the analyzer response to zero and span points
located at approximately 0 % and 80 % respective of the full scale of the measurement range used.
Periodicity: monthly, or more frequently if the installation requires it.
–
Span (multi-point calibration):
This involves a complete checkup of the analyzer’s linearity performance.
Periodicity: quarterly, or following out-of-tolerance calibration check results requiring analyzer
intervention.
Note about gas cylinder connections:
When the analyzer is equipped with an internal zero filter and / or an internal permeation bench,
calibration gas cylinders will be connected to the sample inlet.