4 measurement gas sampling using aspirator – Yokogawa Low Concentration (ppm) Zirconia Oxygen Analyzer OX400 User Manual
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<6. Operation and Parameters>
6-14
IM 11M10B01-01E
6.4 Measurement Gas Sampling Using Aspirator
If you selected “-A”: with an aspirator as the sampling method, an aspirator is included in the OX400
package. Connect the aspirator to the sample gas outlet on the rear panel of the OX400.
If you selected “T”: 1/4NPT as the piping connector, connect an adapter between the sample gas
outlet and the aspirator.
Supply clean air or N
2
gas to the aspirator. The external diameter of the gas supply inlet of the one-
touch connector type aspirator is Ф6, and the gas outlet is Ф8. Do not confuse the supply inlet and gas
outlet when you connect the aspirator.
Connect the adapter if the piping connector is 1/4NPT.
Gas outlet
(for external diameter Φ8)
Supply gas inlet (for external diameter Φ6)
Gas outlet
Air or N
2
gas
Unit: mm
Rear panel of the OX400
Figure 6.18
Example of Connecting Aspirator and Gas Piping
Figure 6.19 shows the relationship between the supply pressure, suction gas flow rate, and total
discharge gas flow rate of the aspirator.
The air supply pressure to the aspirator shall be in the range between 65 and 100 kPaG. Also,
maintain the air supply pressure at a certain value to prevent the pressure from fluctuating. If the
pressure fluctuates, the suction flow rate fluctuates resulting in a fluctuation of measured data. The
allowable pressure fluctuation range is the set pressure ±2 kPaG. Furthermore, the outlet pressure
shall be equal to the atmospheric pressure. Also make sure back pressure is not applied.
Check the sample gas flow rate, and adjust it to 200 ±25 ml/min (a floater should be on the bar of the
200 ml/min bar on flowmeter) using the throttle knob on the front panel after adjusting the air supply
pressure to the aspirator.
0
200
400
600
800
1000
1200
1400
60
65
70
75
80
85
90
95
100
105
6
7
8
9
10
11
12
13
Aspirator’s suction characteristics
Suction flow rate (ml/min)
Aspirator’s total discharge flow rate
Suction flow rate
Aspirator
’s total discharge flow rate (l/min)
Air supply pressure range
Air supply pressure (kPaG)
Figure 6.19
Aspirator’s Suction Characteristics