The instruments trasmitters covert the output of a conductivity electrode into a signal, with temperature compensation, at 4÷20mA. The electrode input circuit is galvanically insulated against the 4÷20 mA output signal. An LCD indicator allows viewing of the process signal value and of the various parameters. The accurate design and choice of components make the instrument precise and reliable for a long working life. The instument works in conjunction with a conductivity electrode and temperature probe (Pt100 sensor, 100 Ohm a 0°C).