Teledyne 2750 - Portable turbine generator gas analzyer - Manual (Page 22)

Installation Model 2750
Teledyne Analytical Instruments 22
Note: Always use two stage regulators on incoming gas lines
from high-pressure sources.
Sample pressure should be set between 0.5—30 psi, typically 5 psig
at the analyzer. CAUTION: HIGH FLOW RATES CAN DAMAGE
THE SENSOR.
3.3 Calibration
The Model 2750 has been calibrated at the factory but will require
periodic recalibration (zero and span).
The calibration gases used to calibrate the instrument are:
Zero: 100% CO
2
for 0-100% H
2
in CO
2
and 0-
100% Air in CO
2
ranges
100% Air for 80-100% H
2
in Air range
Span: 100% air for 0-100% Air in CO
2
range.
100% H
2
for both the 0-100% H
2
in CO
2
and 80-100% H2 in Air ranges
For the best accuracy, the analyzer should be calibrated with the
same gases that will be used to service the generator. This should
compensate for most small impurities that may be present in the service
gases
To calibrate the analyzer, both zero and span values must be set or
verified for each range. Always use the calibration switch position to
verify the zero setting on each range. This is required because the
microcontroller cannot see negative offsets. Use the procedures in
Sections 3.3.1 and 3.3.2 for calibrating the Model 2750.
 Gas to be analyzed or being used for calibration needs to be
pressure regulated to approximately 5 psig and the flow kept
below 1 SFCH or the cell could be damaged
 If the Trim Pots are adjusted too far past 100%, the reading will
return to 0%. If this happens, turn the trim pot back until the
reading drops below 100% and then make the final setting.
Note: Perform a zero calibration before span calibration.