Teledyne 2750 - Portable turbine generator gas analzyer - Manual (Page 26)

Installation Model 2750
Teledyne Analytical Instruments 26
Please note that the 80-100% H
2
in Air range is actually a 0-20% H
2
in
Air range with the 2750 doing the simple calculation to report the
reading as hydrogen purity. Thus the zero adjustment uses 100% air.
The zero calibration is now complete, continue with a span calibration.
3.3.2 Span Calibration Procedure
Note: A zero calibration must be performed before a span
calibration.
CAUTION: ADJUST THE SPAN POT SLOWLY AS THE READING
APPROACHES 100%. IF THE SPAN READING
EXCEEDS 104-105%, THE READING WILL SUDDENLY
DROP BACK TO ZERO. IF THIS HAPPENS SLOWLY
TURN THE SPAN POT IN THE OPPOSITE DIRECTION
UNTIL THE READING COMES BACK TO 100+ AND SET
TO 100%
1. If not immediately following a zero calibration, verify the zero of
the instrument using the procedures in Section 3.3.1.
2. Connect the 100% air to the instrument. Make sure the regulator
is set at approximately 5 psig.
CAUTION: ALWAYS HAVE THE SAMPLE FLOW VALVE CLOSED
WHEN TURNING ON THE SAMPLE (OR CALIBRATION)
GAS SOURCE. FLOW RATES GREATER THAN 2.5
SCFH CAN DAMAGE THE SENSOR.
3. Open the sample valve to flow the span gas. Wait a few minutes
then adjust the flow to 0.5-1 SCFH.
4. Set the calibration switch to ANALYZE and set the range switch to
air/CO2 position. See Figure 3-8.