COSA Xentaur Xentaur LPDT - Manual (Page 8)

Section 1: Introduction
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1.0 Overview of the LPDT
The LPDT is a microprocessor based 4-20mA loop powered
(2 wire) hygrometer, for measuring moisture content in
gases in the range from -100°C to +20°C. The measurement
is displayed on the instrument’s custom LCD, and is trans-
mitted by varying the current drawn (4-20mA) from the
power supply. The current varies linearly proportional to the
selected measurement units. An optional digital output is
available which modulates/demodulates the 4-20mA loop
line without interfering with its operation. With this option
the LPDT is capable of communicating with properly
equipped Personal Computers or other RS-232 capable con-
trollers. Three front panel buttons provide the user with a
wide variety of features. The LPDT’s advanced design
allows it to be housed in a small stainless steel enclosure
behind the sensor probe, thus the instrument and sensor are
a single integrated unit.
The LPDT uses the Xentaur HTF™ sensor which is encap-
sulated in sintered stainless steel, thus it is capable of com-
ing into contact with a wide variety of environments.
However one should keep in mind that the sensor is a sensi-
tive device and it should be handled accordingly.