<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 ø6, and the gas outlet is ø8. 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
8th Edition : Jan. 10, 2019-00
Summary of Contents for OX400
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