Teledyne API Model 100AH SO2 Analyzer Instruction Manual, 02417, Rev. D
10.3.5 Flow/Pressure Sensor
The flow/pressure sensor board consists of 2 pressure sensors. See Figure 10-5 for a diagram of this
assmebly. The flow rate value is computed from these two pressure sensors and displayed on the
front panel TEST functions including two pressure readings. They are:
1. Inlet sample gas pressure - measured directly S1
2. Reaction cell pressure - measured directly S2
The above pressure and flow are filtered to produce the front panel readings. Several minutes
may be required for a steady reading if observing the TEST functions.
Check Pressure
1. Remove the 1/8" fitting from the reaction cell and remove sample inlet tubing for the sample
filter assembly.
2. Scroll to select VAC or PRES of the TEST functions.
3. Check if the pressure readings are close to the current absolute ambient pressure (typical
value at sea level is 29.9 Hg-In). Notice that it must be absolute pressure reading. Check if
both readings do not differ more than 2% from each other.
Pressure Calibration
1. Press SETUP-MORE-DIAG-ENTR and Scroll to select PRESSURE CALIBRATION-
ENTR.
2. Enter the current absolute pressure value in In-Hg.
Check Flow Rate
To calibrate the sample flow, proceed as follows:
1. Scroll to select SAMP FL of the TEST functions.
2. Using independent flow meter verify the flow rate into the reaction cell.
3. If the actual flow differs more 10% of the displayed flow, proceed to flow calibration.
Flow Calibration
1. Press SETUP-MORE-DIAG-ENTR and Scroll to select FLOW CALIBRATION-ENTR.
2. Enter the actual flow value from the independent flow meter.
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