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Verfügbare Sprachen
Verfügbare Sprachen
When continuous purging is needed, make sure that the needle valve set to its open position. Start the purging process with
the highest permitted pressure at the purge inlet. This decreases the necessary time to purge the sensor heads completely
free of ambient air. When the sensor heads are free from ambient air the purge flow can be reduced to values significantly
below 1 l/min. As long as a small overpressure in the sensor heads remains ambient air will not enter.
The pressure at the purge gas inlet should be as close as possible to ambient conditions and should not exceed 1 bar (100
kPa) overpressure compared to ambient pressure.
The recommended purging gas flow is 3 ... 5 l/min at the beginning of the purging procedure and about 0.5 l/min during
normal operation. A too low flow rate and/or too humid purging gas might lead to faulty measurements.
Sensor Purging
In oxygen applications it might be necessary to purge boxes and lens tubes with an oxygen free gas, such as nitrogen. Any
oxygen free gas can be used for this purpose. However, when explosive gases are used the Ex sensor must be used.
Purging with oxygen free gas is also necessary when performing water vapor measurements. The sensors for sensor
purging supplied by Siemens include a needle valve and a check valve (see the figure below).
Purging Set-up
Follow the procedure to mount the purging connectors:
Remove the four plugs from the wedge tube.
Mount the valves and 6 mm tube according to the figure.
Figure 1
Sensor purging set-up
Note
When using a plastic tube, be sure to use the rigid metal insert.
Siemens AG
Digital Industries
Postfach 48 48
90026 NÜRNBERG
GERMANY
Amendment 2 to Sensor CD 6 Operating Instructions
Amendment 2 to Sensor CD 6 Operating Instructions
A5E47707424A, 07/2019
2
A5E47707424A-01, 07/2019
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