Teledyne 306WA - Analog trace oxygen analyzer User Manual

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2-6

2.0 Operational Theory

Model 306W

Model 306WA

TELEDYNE ELECTRONIC TECHNOLOGIES

Analytical Instruments

The three ranges of the analyzer are intended primarily to make calib-

ration convenient. It is expected that the oxygen content of the sample being
analyzed will be within the narrow range (Range No. 1) of the analyzer.
Then when the analyzer is switched to Range No. 2, a sufficiently large
amount of oxygen can be added by the calibrator to five a reliable calibra-
tion. Since the calibration is dependent on adjusting the change in indica-
tion, this change should be as large as possible—at least 50% of the wider
range.

For example:

Analyzer range:

0-1, 0-100, 0-1000

Sample reading:

18 PPM

Check calibration:

Adjust the analyzer calibration potentiometer so that 50 ppm of oxygen

is being added to the sample. This is the change in actual oxygen content of
the sample.

Assume that the analyzer changes its output to read 52.

The change in output indications is 52 - 18 = 34 when 50 PPM O

added. Therefore, the span potentiometer should be adjusted to give a
reading of

(18 x 50) + 50 = 76.5 PPM

NOTE:

NOTE: For details, see Appendix: Calibration Considerations.

For details, see Appendix: Calibration Considerations.