Star A325 pH/Conductivity HH Meter pH Range -2 to 20 Waterproof IP67 Automatic Temperature Compensation Yes Displayed Temperature Range 0 Degrees to 120 Degrees Operating Temp Range (F) 0 Degrees to 120 Degrees F Display High Resolution Mono-chromatic Auto Power Off Yes Calibration 5 point Power Source AC or (4) AA Battery Includes Star A325 pH/Conductivity HH Meter Manufacturers Warranty Length 36 mo Testing Parameter pH/Cond