Vaisala DM70 - Manual (Page 56)

USER'S GUIDE____________________________________________________________________
8. Set the probe into the sample cell. Tighten the probe by turning
it from the thread nut. Do not tighten the probe from the handle.
9. If the sample cell is installed correctly, there is no leakage in the
connections. You can test this by closing the valve temporarily.
CAUTION By using the quick connector, the process pressure can be maintained
during the installation or removal of the sampling cell. Take a firm
hold of the device to keep it in your hands while removing it. When
the thread adapters are used, the process pressure has to be shut down
for the installation or removal of the probe.
DSS70A Sampling System
DSS70A is a sampling system for taking gas samples from hot, dirty,
or pressurized processes. The gas collecting system is built in the
briefcase including the DM70 meter. The system consists of a sample
pump that draws out the sample gas, a filter to clean the sample from
particles
(> 7µm), and a sample valve and flowmeter to adjust the flow rate.
Sample Gas
Inlet
Sample Gas
Outlet
Sample Pump Flowmeter Sample valve
Sample Cell
for Td Probe Filter
The sample gas going into the system must meet the following
requirements:
- The temperature must be <40 ˚C (104 ˚F). Thus, when using
the FEP tube of 2 meters (provided), the temperature of the
process gas should be less than 200 ˚C (392 ˚F). When the
temperature of the sample gas is over 200 ˚C, a stainless steel
tube (not provided) should be used.
- The sample gases must be: Air, N
2
, non-toxic gases, inert,
non-flammable gases.
- If the sample is taken from a pressurized process (1.2 ... 20
bar), the sample pump must be turned off and the tube from
the flowmeter to the pump must be detached.
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