OM371 : Compact Dew Point Temperature Transmitter / Switch

Model :OM371
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Applications :

The exact monitoring of dew point temperature in compressed air systems, dryers for plastic and other indus¬trial processes is becoming increasingly more important. 0M371 series with a measuring range -60…60°C Td (-112…140°F Td) is the ideal solution for such applications. The core of the transmitter is the monolithic measurement cell type HMC01, developed by Omicron Sensing in thin film technology.An autocalibration procedure which is integrated in the device and years of experience in low humidity adjustment make an accuracy of <2°C Td (±3.6°F Td) possible. The compact construction in a robust aluminium housing and the numerous options allow easy mounting and many application possibilities.


Dew point temperatures in the range of -60…-20°C (-76…-4°F) at room temperature correspond to relative humidity values of 0.08…5.37% RH. The measurement of these low humidity values is not possible with conventional capacitive measurement methods. For the 0M371 series a special autocalibration procedure is utilized to achieve high accuracy measurements at lowest dew points too.


Additional information

Measuring Quantities

Dew Point (Td) Dew Point Sensor

: HMC01


: Traceable to intern. standards, administrated

Response Time t90

80 sec. -20°C Td —> -40°C Td (-4°F Td —> -40°F Td)
10 sec -40°C Td —> -20°C Td (-40°F Td —> -4°F Td)

Volume concentration

Measuring range

: 20…200 000ppm

Accuracy at 20°C (68°F) and 1013mbar

: 5ppm + 20% of reading


Selectable and scalable

: 0 – 10V -1mA< I,< 1mA

analogue output for Td, Tf, Wv

: 4 – 20mA R < 500 Ohm


Supply Voltage

: 21…28V DC

Current Consumption at 24V DC

: voltage output: typ. 40mA / during autocalibration: 100mA

Pressure Range

: 0…20bar (0…290psi)

Housing / protection class

: Al Si Cu 3 / IP65

Electrical connection

: M12 connector

Sensor protection

: stainless steel sintered filter

Working temperature range

: probe: -40…70°C (-40…158°F)
electronic. -40…60°C (-40 140°F)

Storage temperature range

: -40…60°C (-40…140°F)


: EN 61326-1 EN61326-2-3 ICES-003 ClassB

compatibility according to

: Industrial Environment FCC Part15 ClassB