20
CI/AZ40-EN Rev. A
Setting up and recording pneumatic values
Referring to Fig. 22.
1. Perform a leak test on all pneumatic connections.
2. Attach a pressure measuring device to sensor assembly
instrument air supply tee fitting
A
. Verify that the instrument
air supply pressure is 207 ±3 kPa (30.0 ±0.5 psi) and adjust
the pressure if necessary.
3. Attach a pressure measuring device with a range of 0 to
–69 kPa (0 to –10 psig) to aspirator suction pressure port
B
. Verify that the suction pressure is –51.7 to –65.5 kPa (–
7.5 to –9.5 psig).
Record the suction pressure in Table 4.
4. Attach a pressure measuring device (inches H
2
O) to test gas
port
C
. Measure the pressure with instrument air on to
obtain the sample pressure.
Record the sample pressure in Table 4.
5. Measure the pressure at test gas port
C
with the instrument
air turned off to obtain the duct pressure. Verify that the
sample duct is –5 to 5 kPa (–20 to 20 inches H
2
O).
Turn the instrument air back on after taking this
measurement.
Record the duct pressure in Table 4.
6. Calculate the filter pressure drop by subtracting the sample
pressure from the duct pressure. Verify that the filter pressure
drop is less than 2 kPa (8 inches H
2
O).
Record the filter pressure drop in Table 4.
Fig. 22 Pneumatic value check points on AZ40 sensor
+
–
+
–
Parameter
Date
New analyzer
Pressure and flow limits
Sample pressure
____________
kPa (in. H
2
O)
_____
_____
Duct pressure
____________
kPa (in. H
2
O)
_____
±5 kPa (±20 in. H
2
O)
Filter pressure drop
(duct pressure – sample pressure)
____________
kPa (in. H
2
O)
0.5 kPa (in. H
2
O)
2 kPa (8 in. H
2
O)
Aspirator suction pressure
____________
kPa (psig)
55 to 69 kPa (8 to 10 psig)
34 to 69 kPa (5 to 10 psig)
Minimum sample gas flowrate
____________
SCFH (i/min)
3.5 to 4.5 SCFH (1.6 to 2.1 i/m)
2.5 to 4.7 SCFH (1.2 to 2.2 l/m)
Table 4 Sensor assembly pressure and flow data
