TECHNICAL BULLETIN
Part #: 026-4807 Revision 0 Date: 02/26/2003
COMPUTER PROCESS CONTROLS - http://www.cpcus.com/
Page 1
Duct-Mounted Humidity Sensor (P/N 203-5771)
Installation Instructions
CPC specs a duct-mounted relative humidity (RH) sensor with a 0-5VDC output for use in build-
ing control and anti-sweat control applications using CPC input boards.
Specifications
Choosing a Mounting Location
Select a supply air duct that draws air from the area in which you wish to measure relative humid-
ity. You may mount the sensor in any orientation provided the sensor element is in the air stream.
Mounting
1.
Cut a small circular hole in the duct large
enough for the sensor tube to fit through.
2.
Bolt the sensor enclosure against the outside of
the duct wall so that the sensor element fits
through the hole and into the duct. The enclo-
sure may be mounted horizontally (as shown in
Figure 1
) or vertically. The screws should be
tight enough for the foam gasket around the
bottom of the sensor to form an airtight seal
between the hole in the duct wall and the out-
side air.
Sensing Element
Digitally profiled thin-film capacitive
Analog Output
0-5VDC; 3-wire, observe polarity
Accuracy
±2% RH over the range 20%-90% RH
Scaling
0-100% RH
Stability
±1%@ 20°C (68°F) annually for 2 years
Input Power
12VDC
Operating
Humidity Range
0-100% RH
EMC
Conformance
EN 50081-1, EN 50082-1, EN 61000-4-4,
EN 61000-4-5, EN 61000-4-3, ENV
50204, EN 61000-4-6
Temperature
Coefficient
±0.03% RH /°C over 0-60°C (32-140°F)
Figure 1 - Humidity Sensor - Exploded View
