COSA Xentaur Xentaur LPDT - Manual (Page 23)

LPDT User’s Manual
page 16
LPDT (the tension washer should be compressed), so that it
does not come loose during use.
3.3.2 Electrical Installation
The LPDT will operate properly with 10VDC to 33VDC at
its input, if this voltage is exceeded the internal fuse may
blow. When selecting the power supply voltage do not
neglect the drop across any current measurement resistor
and wiring in the loop. The connector is a standard 2.1mm x
5.5mm (12mm minimum barrel length) DC power jack, an
internal diode bridge accommodates either polarity. The
LPDT may be powered using an off-the-shelf wall trans-
former with 2.1mm connector, or from a power supply
using the provided connectorized cable. The provided cable
is terminated with a connector which has a retainer, the
retainer may be used to secure the connector to the LPDT
thus avoiding accidental disconnection.
The LPDT will draw 4mA to 20mA from the power supply
depending on the dewpoint being measured. The dewpoints
corresponding to 4mA and to 20mA are user selectable, in
between the current will vary linearly to the selected engi-
neering units, see appendix G.
Various strategies for interfacing with the LPDT are shown
in Appendix D.
Please observe good electrical safety and grounding prac-
tices when connecting any electrical equipment; connecting
one end (e.g. negative) of the power supply to earth ground
is advisable.
After the installation is complete, proper detection by the
user’s equipment of the 4-20mA output, may be tested using
the Analog Output test feature of the LPDT, see section
3.4.5.6.