The PHT transmitter converts the high impedance voltage output of pH or REDOX (ORP) probes into standard current or voltage signal that can be safely sent over longer distances. The transmitter provides the necessary for the normal pH/ORP probe’s operation high input impedance as well as temperature compensation of pH measurement through a Pt100 or Pt1000 temperature sensor connected to the second transmitter input. Four variants are available differing by power supply, output signal, type of mounting, and protection class. The PHT transmitter is applicable in all cases in which there is a need for measuring pH or ORP and the measurement signal has to be sent over relatively long distance from the point of measurement.