Reading And Recording Data - Teledyne 2120 Operating Instructions Manual

Trace Nitrogen in Argon Analyzer
For 0-2 ppm range: Adjust the plate adjustment
potentiometer on the rear panel to obtain a reading in
mVDC equal to 70 times the span calibration gas in ppm
(i.e., with a span gas of 1.8 ppm, the millivolt reading
should be 126 mVDC).
Note: This is an approximate reading. This initial setting is
changed only when some major part of the analyzer is
changed or the 1P28 phototube becomes weak with age.
Then the plate adjustment control may require additional
adjustment to keep the analyzer calibrated.
5. With span gas flowing at a rate of 2 cfh (940 ccpm), and the
output stabilized, adjust the SPAN potentiometer to obtain a
reading on the panel meter equal to the span gas in ppm
nitrogen.
6. Stop the span gas and start flowing zero calibration gas to the
analytical cell at a rate of 2 cfh (940 ccpm). Wait
approximately 30 minutes for the digital panel meter reading to
stabilize. Adjust the ZERO potentiometer to obtain a reading on
the panel meter equal to the zero gas in ppm nitrogen.
7. Repeat steps 5 and 6 until stable zero and span readings are
obtained without further adjustments.
8. When calibration is complete, close the span and zero inlet
lines, and record the settings of the ZERO, SPAN, and the plate
adjustment potentiometers on your equipment calibration
log. A sample equipment calibration log is included in
the Appendix of this manual for your convenience. Subsequent
calibrations modify these settings, and you may find that a
record of the changes is useful when troubleshooting analyzer
problems.

4.3 Reading and Recording Data

CAUTION: THE DIGITAL PANEL METER MAY INDICATE A
NEGATIVE VALUE OR DISPLAY A CONSTANT "1"
WHEN HIGH CONCENTRATIONS OF NITROGEN
(≥ 0.5 PERCENT) ARE PRESENT. NO MATTER
WHAT THE DIGITAL DISPLAY INDICATES, AN
Teledyne Analytical Instruments
Operation
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