Teledyne 9700 - Flue gas analysis system - Manual (Page 31)

4-3
Flue Gas Analysis System Operation 4
TELEDYNE BROWN ENGINEERING
Analytical Instruments
If, on the other hand, reliable analysis, free of instrument distortion, is
required from the very onset of operation, TBE/AI recommends a 24 hour
run-in period before operational calibration and service .
In either case, emlploy the following procedure:
(1) Set the analyzer RANGE switch to the 0–25% position. Power
has now been applied to the instrument circuitry and to the
sample pump.
(2) Rotate the sample-caibration selector valve so that calibration or
span gas is being delivered to the analyzer.
Note: When the valve is rotated so that the handle index faces the inside
of the case (open port), atmosplleric air is drawn in by the pump
and flows through the oxygen analyzer. Be sure that the valve is
returned to the sample inlet position after calibration is completed.
Never leave the valve in the half-way (closed) position with the
pump running.
(3) Allow air to flow through the unit for 3 to 5 minutes.
(4) Unlock and adjust the SPAN control until the meter pointer is
in coincidence with the CAL mark (20.9% O
2
) on the meter
scale. Relock the SPAN control.
(5) Rotate the selector valve so that sample gas is flowing through
the analyzer.
(6) Select the range of analysis that will provide the best possible
resolution of the oxygen content of the sample gas.
(7) Allow sample gas, not calibration air, to flow through the
analyzer for the duration of the equilibration period.
Note: It is particularly vital to the condition of the A-3 cell employed in
flue gas (or high CO
2
content applications) that the cell not be
exposed to a CO
2
free environment for a prolonged period of time.