Vaisala HUMICAP DMT132, User Manual

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The DSC74B limits the flow rate with a fixed leak screw. The flow is optimized for pressures
3 ... 10 barg. The fixed leak screw eliminates the risk of opening the leak screw fully by
accident and this way emptying a gas vessel. The maximum flow can be increased, if
needed, by removing the leak screw and adjusting the flow manually with the valve. Harmful
gases can be recovered by connecting a collection system at the outlet (not available from
Vaisala).
In the basic operation of the DSC74B, the gas flows to the sensor from the front and the
outlet is on the side. To have the measurement done at atmospheric pressure, the inlet and
outlet are reversed. Then the reducing parts supplied (G3/8" to G1/2" or G3/8" to G1/4") on
the outlet side help to protect the sensor from ambient humidity coming in.
DSC74B consists of the following parts:
• Sampling cell, thread 3/8"G
• Connection part with a needle valve and an integrated leak screw
• Reducing Nipple (thread adapter), G3/8" to G1/2"
• Reducing Adapter (thread adapter), G3/8" to G1/4"
1
2
Figure 18 DSC74B
1 Gas goes in
2 Gas comes out
DMT132 User Guide M211289EN-B
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