Electric, electronic and electrochemical measuring apparatus for analysing gases and liquids; namely, pH-sensors, pH-transmitters oxidation-reduction-potential-sensors, oxidation-reduction-potential-transmitters, conductivity sensors, conductivity transmitters, turbidity-sensors, turbidity-transmitters, gas-sensors, oxygen-transmitters, nitrogen transmitters, transmitters for the detection of total organic content in aqueous media, sludge level transmitters, water-samplers; software for contr...