Metek 920, Operator'S Manual With Essential Health And Safety Requirements

Page: 160 / 278

4-52 | Model 920 Multi-Gas Analyzer
5. The high range SO
2
is already factory calibrated. The Span Factor can
be adjusted, by repeating the previous step.
Use high range SO
2
, not low range SO
2
.
6. Enter the component concentration of Species 4 ( Conc4 ) from the tag
concentration of the calibration cylinder.
Example:
If the tag concentration is 250 ppm, key in:
F4 4 Del 250 Ent Ent
7. Perform a Manual Zero by turning on the Zero gas, and pressing F2 0 .
Run Zero gas through the analyzer for at least 5 minutes.
When the readings have stabilized at or near ‘ 0 ’, press Ent . Turn off
the Zero gas.
8. Span the high range SO
2
by turning on the Calibration gas mixture, and
pressing F2 4 . Run the high range Span gas through the analyzer for at
least 5 minutes. Typical flow rates are 1–2 SCFH.
When the readings have stabilized at or near ‘ 0 ’, press Ent . Turn off
the Calibration gas.

NOTE