Test Meter pH/ORP/TDS/Conductivity/Salinity pH Range -2.00 to 16.00 Electric Conductivity Range 0 to 200 mS TDS Range 0 to 100 ppt ORP Range -2000 to 2000 mV Waterproof IP67 Automatic Temperature Compensation Yes Displayed Temperature Range -22 to 266 Degrees F -30 Degrees to 130 Degrees C Salinity Range 0 to 100 ppt Operating Temp Range (F) -22 Degrees to 266 Degrees F Operating Temp Range (C) -30 Degrees to 130 Degrees C Resistivity Range 0 to 20.000 megaohms