The Milwaukee Waterproof pH55 PRO pH/Temp Tester with ATC is one of our most accurate cost effective, well rounded, rugged and reliable testers in the market featuring dual level LCD readouts, easily replaceable probe and extended pH ranges to meet almost any application. It's simple 1 or 2 point automatic calibration is simple-to-use and offers TWO sets of memorized buffers to select. Ideal for use in aquariums, hydroponics, horticulture, education, pools, beer and many other applications.DESIGN FEATURESFast easy to read results with large digital LCD readout.Extreme pH accuracy to ±0.1 pH with an extended pH range (-2.0 pH to 16.0 pH).Resolution to 0.1 pH.Lightweight and portable.Easy measurement: just place the probe in the sample, gently stir, wait for the stability indication to show a stable reading and then freeze the reading.Simple Automatic one or two-point calibration.2 Sets of pre-memorized buffers.Gel-filled, double junction pH electrode for low maintenance and high performance.Over 300 hours of battery life (batteries included).Fully waterproof to IP65.Replaceable pH electrode Mi56P.SPECIFICATIONSpH Range: -2.0 to 16.0 pHTemperature Range: -5.0 to 60.0°C (23 to 140°F)pH Resolution: 0.1 pHpH Accuracy: ±0.1 pHTemperature Accuracy: ±0.5°C (±1°F)Typical EMC Deviation: ±0.1Typical EMC Temperature Deviation: ±0.3°C (±0.6°F)Temperature Compensation: Automatic from -5 to 60°C (23 to 140°F)Calibration Automatic: 1 or 2 points with 2 sets of pre-memorized buffers (pH 4.01, 7.01, 10.01) or (pH 4.01, 6.86, 9.18)Probe: Replaceable double junction for extended life (Mi56P)Environment: -5 to 50°C / 23 to 122°F; max RH 100%Battery Type: 4 x 1.5V; IEC LR44, A76 (included)Battery Life: Approx. 300 hours of useAuto-off: after 8 minutes on non-useDimensions: 254 × 67 × 47 mmWeight: 99.22 gCARE AND USEAll pH sensors have a limited life and response time gets longer with age. Properly maintaining your pH Tester will give you fast, accurate results for longer.Here are our top four tips. 1. Always store with the cap full of buffer or storage solution MA9015 not water.2. Clean your Tester regularly by soaking in cleaning solution MA9016.3. Calibrate after cleaning and/or storage before testing to adjust for changes in the pH sensor.4. Gently stir the Tester in the sample for a faster result.