COSA Xentaur Xentaur HDT - Manual (Page 8)

Section 1: Introduction
page 1
1.0 Overview of the HDT
The HDT is a microprocessor based 4-20mA loop powered
(2 wire) hygrometer, for measuring moisture content in
gases or liquids in a wide range from -100°C to +20°C dew-
point in gases; and 0 ppmW to 1000 ppmW in liquids. The
measurement is transmitted by varying the current drawn
(4-20mA) from the power supply. The current varies lin-
early proportional to the selected measurement units. In
addition a digital output modulates/demodulates the 4-
20mA loop line without interfering with its operation, and
adheres to the HART protocol. Thus the HDT is capable of
communicating with properly equipped Personal Computers
or other RS-232 or HART capable controllers. The HDT’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 HDT uses the Xentaur HTF™ sensor which is encapsu-
lated in sintered stainless steel, thus it is capable of coming
into contact with a wide variety of environments. However
one should keep in mind that the sensor is a sensitive device
and it should be handled accordingly.