13
Model DS1200-PDT - Dewpoint Hygrometer
Installing and Commissioning the Model PDT Transmitter
It is advisable to carry out an initial purge of the sample loop, before installing the
transmitter, in order to reduce the possibility of sensor damage on start-up.
Refer to the sample system schematic on
page 11
. Open the inlet isolation valve slowly,
until a small flow of air/gas at atmospheric pressure flows through the inlet pipe work to
the transmitter holder and exhausts through the sensor entry port of the transmitter
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 transmitter into the transmitter holder. Locate
and secure the cable connector in position on the transmitter. Use the locking screw in
order to affect a weatherproof seal.
Open the inlet valve slowly again and, by opening all valves after the transmitter 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.
Setting the Alarm Trip
Points
To activate the quick alarm
settings screen press either the ”
” or ” ” buttons, while the
DS1200 is displaying the moisture
level.
The DS1200 will flash the “F.SET”
message followed by a selection
menu for Alarm 1 or 2 relay. Scroll
to the required alarm and press
the “OK” button.
The DS1200 then displays the
message “SETP” momentarily
before displaying the current set
point in % of scale.
