Read more Waterproof EC TDS Temp Pocket Testers – Higher Range AD32 is a waterproof Conductivity, TDS and temperature testers. The housing has been completely sealed against humidity. All Conductivity and TDS readings are automatically temperature compensated (ATC), and temperature values can be displayed in °C or °F units. The Conductivity/TDS conversion factor (CONV) can be selected at one point. Measurements are highly accurated with a unique stability indicator right on the LCD.