TDS/Conductivity/Salinity Pen Electric Conductivity Range 0 to 199.9 micronS/cm 200 to 1999 micronS/cm 2.00 to 19.99 mS/cm TDS Range 0 to 99.9 ppm 100 to 999 ppm 1.00 to 9.99 ppt Oxygen Concentration - Salinity Range 0 to 99.9 ppm 100 to 999 ppm 1.00 to 9.99 ppt Free Chlorine - Total Chlorine - Temp Range (F) 32 to 149 Degrees F Temp Range (C) 0 to 65 Display LCD With Bargraph Auto Power Off Yes Memory Stores 15 Labeled Readings Temperature Compensation Range 32 To 140F/0 T