Alpha Moisture Systems dewTEC DS2000, Инструкция по эксплуатации

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4) Pressure Reduction Valve or Pressure Regulator – If the sample is to be measured at
atmospheric pressure then the valve 4A should be fitted and 4B omitted from the
system. If the sample is to be measured, at full line pressure and the exhaust vented to
atmosphere, then valve 4B should be fitted and 4A omitted from the system. If
measurements are to be taken at full line pressure and the sample is to be returned to a
part of the main line or a vent, which is at a pressure higher than atmospheric, and the
input to that line needs a controlled pressure then both 4A and 4B will be required.
5) Sample Pressure Gauge – This is not a critical part of the moisture measurement but
may be required if Dew/Frost point measurements are to be made at higher than
atmospheric pressure.
6) Measuring Sensor .
7) Sensor Holder .
8) Desiccant Chamber – This item is required when the sampling is to be intermittent.
When installed it prevents the ingress of wet air to the sample system, while the
sample is not flowing, improving the response time.
9) Flow Control Valve – This can be a separate item or combined with the flow indicator.
10) Flow Indicator – The recommended sample flow is 2 to 3 SL/M.
Sample Exhaust – The exhaust can be vented to atmosphere or returned to the process line as
discussed above.
2.5 Installing and commissioning the sensor
It is advisable to carry out an initial purge routine of the sample loop, before installing the
sensor, in order to remove the possibility of sensor damage on start-up.
Referring to the sample system schematic in section 3.4, open the inlet isolation valve slowly,
until a small flow of air/gas at atmospheric pressure flows through the inlet pipe work to the
sensor holder and exhausts through the sensor entry port of the sensor holder.
Allow this purge to continue for about 15 to 20 minutes to remove any residual moisture from
the sample pipe work and components.
Close the inlet isolation valve and install the sensor into the sensor holder. Securely push fit
the coaxial sensor cable connector in position on the sensor.
Open the inlet valve slowly, again and, by opening all valves after the sensor holder, allow a
low-pressure purge through the whole sample system. (Note. If a closed by-pass loop is
installed, this section of the procedure is not possible).
Set the required pressures and flows within the sample loop.
This completes the installation and commissioning but, on initial start-up, it could take several
hours for the system to reach equilibrium.
dewTEC DS2000 User’s Manual Page 5