Filter
Top Products
Calibration Procedures Teledyne API - Model 200EH/EM Operation Manual
172
7.8. CALIBRATION QUALITY ANALYSIS
After completing one of the calibration procedures described above, it is important to evaluate the analyzer’s
calibration
SLOPE and OFFSET parameters. These values describe the linear response curve of the analyzer,
separately for NO and NO
X
. The values for these terms, both individually and relative to each other, indicate the
quality of the calibration. To perform this quality evaluation, you will need to record the values of the following
test functions (Section 6.2.1 or Appendix A-3), all of which are aut
omatically stored in the iDAS channel
CALDAT for data analysis, documentation and archival.
NO OFFS
NO SLOPE
NOX OFFS
NOX SLOPE
Make sure that these parameters are within the limits listed in Table 7-5 and frequently compare them to those
values on the Final Test and Checkout Sheet that came attached to your manual, which should not be
significantly different. If they are, refer to the troubleshooting Chapter 11.
Table 7-5: Calibration Data Quality Evaluation
FUNCTION MINIMUM VALUE OPTIMUM VALUE MAXIMUM VALUE
NOX SLOPE
-0.700 1.000 1.300
NO SLOPE
-0.700 1.000 1.300
NOX OFFS
-20.0 mV 0.0 mV 150.0 mV
NO OFFS
-20.0 mV 0.0 mV 150.0 mV
The default iDAS configuration records all calibration values in channel CALDAT as well as all calibration check
(zero and span) values in its internal memory. Up to 200 data points are stored for up 4 years of data (on
weekly calibration checks) and a lifetime history of monthly calibrations. Review these data to see if the zero
and span responses change over time. These channels also store the STABIL value (standard deviation of NO
X
concentration) to evaluate if the analyzer response has properly leveled off during the calibration procedure.
Finally, the CALDAT channel also stores the converter efficiency for review and documentation.
USER NOTES:
04521C (DCN5731)