12VDC to 30VDC Power , Dew Point Transmitter , 4mA to 20mA and Analog Output Settings

DPT 820

The DPT-820 measures moisture content in gasses in the range -110℃ dp to +20℃ dp and provide a 4-20mA output linear to the measurement units chosen.The factory default is 4mA=-110 ℃and 20mA= +20℃.The defaults can bu modified in value and units (available units:℃ dewpoint, ppmV,RH%).The DPT-820 is a Loop-Powered Blind (three wire)Transmitter;it has display self and can consuming power in the range of 4mA to 20mA

Sensor Operating Principle

The nanopore sensor utilized in this analyzer measures the amount of water vapor molecules that have entered its pores.This amount is directly proportional to the partial water vapor pressure in the gas surrounding the sensor,and the partial water vapor pressure is dependant on the water vapor content of the gas and the total pressure of the gas,Thus to compute the water vapor content of the gas under measurement the analyzer has to “know”the total pressure of the gas.Since there is no built-in pressure sensor,the user should enter the total pressure into the analyzer,this can be easily done by entering atmospheric pressure(the analyzer default setting)and measuring at atmospheric pressure by allowing the sample cell outlet(exhaust)port to vent without restrictions.

The DPT-820 can be mounted directly Connections for inlet and outlet of the gas being measured are made through a variety of available options e.g.1/8”or 1/4”Swagelok tubing compression fittings

The DPT-820 is 4/20mA loop powered analyzers.The analyzer will operate from 12VDC to 30VDC power and will draw 4mA to 20mAdepending on the measurement and the analog output settings(factory default 4mA=-110 and 20mA=+20).