Features:Fast easy-to-read results with large duel level digital LCD readout.Extreme accuracy to ±0.002 pH / +/- 1 mV OPR / +/- 0.4°C (+/-0.8°F). Extended pH range (-2.00 pH to 20.00 pH / -2.000 to 20.000 pH).Lightweight, sleek design with small benchtop footprint.Simple easy-to-use logging and USB download functions, manual or on stability up to 1,000 logs.Electrode diagnostics feature checks and displays the condition of the pH electrode. Easy measurement: just place the electrode and temperature probe in the sample, gently stir and wait for the reading to stabilize.Simple push button, automatic up to 5 point calibration for increased accuracy.Up to 7 Standard calibration solutions (1.68, 4.01, 6.86,7.01, 9.18, 10.01 and 12.45) and 2 custom choices.Refillable, glass, double junction lab grade pH electrode for low maintenance and high performance with a screw on cap to ensure proper storage.Built-in rechargeable battery with 8 hours battery life (battery included).Selectable Auto-off feature. Alphanumeric LCD display messages for friendly, intuitive information, warnings and error messages.Internal clock date to keep track of different time-dependent functions (calibration, timestamp,calibration time out).3 feet probe cables for extra flexibility when testing.The Milwaukee MW151 MAX 3-in-1 pH/OPR/Temp. Logging Portable Bench Meter has won fans around the world with its reliable, fast and simple operation as well as its tough, sleek design with a small lab footprint. The MW151 MAX is accurate to ± 0.002 pH with automatic or manual temperature compensation with a built in dedicated GLP key. Ideal for use by brewers, wine makers, growers, labs, food processing, water treatment and many other applications with challenging pH measurement needs.The Milwaukee MW151 MAX 3-in-1 PRO pH/ORP/Temp Bench Logging Meter is preferred by people testing all types of samples viscus or not, in a variety of applications that cause other pH meters and electrodes to fail. The logging feature allows log-on-demand and log-on-stability features that ensure all readings are accurate and not entered incorrectly. The MA917B/1 Milwaukee double junction electrode is refillable and easy to clean. From brewers and wine makers to hydroponic growers, labs and water treatment, the MW151 MAX is your Bench Logging Meter for fast, accurate readings. The Milwaukee MW151 MAX pH Bench meter offers:People choose the MW151 MAX 3-in-1 PRO pH/ORP/Temp Portable Logging Meter to improve the accuracy of their testing program. With up to 5 point calibration and 7 standard buffer choices (2 custom buffers also), the meter can be quickly calibrated to a higher accuracy compared with one or two point calibration. The MW151 MAX meter is accurate to ± 0.002 pH. 8 x more accurate than some alternative meters. The meter comes with a refillable, glass, double junction pH electrode and MA831R temperature sensor allowing the meter to automatically adjust the pH reading for the effect of temperature (ATC). The meter can also be used as a very accurate thermometer with accuracy +/-0.4°C (+/-0.8°F).The MW151 MAX pH/OPR/Temp Bench Logging Meter comes with the Milwaukee glass, double junction MA917B/1 pH electrode. This is Milwaukee's top selling lab grade electrode for a reason. Designed to be both low maintenance (refillable) and able to withstand more challenging samples (double junction). The MA917B/1 is ideal for use in beer making, winemaking, hydroponics, laboratories and many other applications.pH meters usually start performing poorly because of problems with the probe. The two parts of the pH probe that cause problems are the glass sensing bulb and the reference junction.The pH sensing bulbs become less sensitive over time so make sure that you are calibrating regularly to keep your PRO Plus pH meter accurate. Also, calibrate after cleaning or a long period of storage.