Voltcraft lwt atc conductivity meters and accessories voltcraft lwt 03 the voltcraft lwt 03 measures conductance due to total dissolved solids tds of aqueous media and is highly accurate due to its automatic temperature compensation function supplied with a conductance probe and operating instructions applications include determining the water quality in schools laboratories fish farms aquaria or during food production supplied with a 1430scm calibration solution 2 x cr2032 batter