Teledyne 6200A - Sulfides analyzer - Manual (Page 117)

TAI Model 6200A SO
2
Analyzer Operator Manual, 02164, Rev. G
All monitoring instrument systems are subject to some drift and variation in internal parameters
and cannot be expected to maintain accurate calibration over long periods of time. Therefore, it
is necessary to dynamically check the calibration relationship on a predetermined schedule. Zero
and span checks must be used to document that the data remains within control limits. These
checks are also used in data reduction and validation. Table 7-9 summarizes the initial quality
assurance activities for calibrating equipment. Table 7-10 is a matrix for the actual dynamic
calibration procedure.
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 so that it is
fully warmed up and its operation has stabilized. During the calibration, the 6200A 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 (see Section 7.9). Calibration documentation should be maintained
with each analyzer and also in a central backup file.
7.8.2 Calibration Gas Sources
Compressed SO
2
in nitrogen
The NIST-SRM's provide references against which all calibration gas mixtures must be
compared (Section 2.0.7, Q.A. Handbook). The procedure requires the comparison of the
concentration of a commercial, working calibration standard to an NIST-SRM. This is described
in Subsection 7.1 of Section 2.0.7, Q.A. Handbook. Subsections 7.1.4 and 7.1.5 describe the
verification and reanalysis of cylinder gases.
SO
2
permeation tubes
The steps required to compare the concentration of a commercial working calibration standard to
an NIST-SRM are described in Subsection 7.2.3 of Section 2.0.7, Q.A. Handbook. See
Subsection 7.2.6 for the re-analysis of permeation tubes.
Dilution air
Zero air (free of contaminants that could cause a detectable response with the Sulfur Dioxide
Analyzer) is commercially available, or can be generated by the user. A clean air system
utilizing ambient air may be more desirable to use for zero and dilution purposes. If compressed
air cylinder is used, the air should have O
2
, N
2
, and CO
2
content similar to that of ambient air
and less than 0.1ppm aromatic hydrocarbons.
7-10