Waterproof Conductivity Kit pH Range -2.00 to 19.99 Electric Conductivity Range 0.00 to 199.9mS TDS Range 0 to 100 ppm ORP Range -1999 to 1999mV Oxygen Concentration - Waterproof Yes Automatic Temperature Compensation Yes Displayed Temperature Range 0 Degrees to 50 Degrees C 32 Degrees to 122 Degrees F Salinity Range 0 to 100ppt Free Chlorine - Total Chlorine - Turbidity Range - Operating Temp Range (F) 32 Degrees to 212 Degrees F Resistivity Range 0 to 100M Ohms/cm