The Myron L Company FCE function reports FAC quickly and accurately by measuring ORP, the chemical characteristic of chlorine that directly reflects its effectivity, cross referenced with pH. Both DPD kits and colorimeters may tell the user the FAC value of the sample in the test tube, but since the chemistry of that sample is quite different from the source water being analyzed, the results are imprecisely related to actual disinfection power. The Myron L Company FCE function measures the real, unaltered chemistry of source water, including moment-to-moment changes in that chemistry. Accuracy of BETTER than ±1% of readingAutoranging Conductivity/TDSSuperior resolution 4 Digit LCD displays full 9999 µS/ppmReal Time Clock with Date and TimeData Logging with Date and Time stamped in memoryWaterproof to 1 meter/3 feetpH Calibration PromptsLow battery indicatorUser adjustable timeout "Auto-off "All Sensors are internal for maximum protectionDownload capability with optional uDock™Display 4 Digit Liquid Crystal DisplayDimensions: LxWxH 196 x 68 x 64 mm/ 7.7 x 2.7 x 2.5 in.Weight 352 g/12.4 oz.Case/conductivity cell material VALOX*Cell capacities pH/ORP: 1,2 ml/0.04 oz.Cond/TDS/MIN/SALT: 5 ml/0.2 oz.Power 9V alkaline batteryBattery life 100 hours (5000 readings)Operating/storage temperature 0 – 55°C/32 – 132°FProtection ratings IP67/NEMA 6 Waterproof to 1 meter/3 feet