Environmental Express Oakton pHTestr 30+ Waterproof Pocket Tester Versatile, compact design works in a field or laboratory setting Waterproof pHTestr 30 is great for outdoor applications such as taking pH measurements in lakes and streams. Double-junction electrode sensor handles wastewater and solutions containing sulfides, heavy metals, and Tris. A replaceable sensor provides easy maintenance. Electrode sensor offers a clog-resistant Kynar junction and a recessed, glass pH bulb to protect against breakage. Valox sensor housing resists most chemicals. Item number 35634-30 includes protective storage case, lanyard, and batteries Large easy-to-read LCD with 3-color backlightAccuracy of ±0.01 pH ± 1 digit1, 2, or 3 calibration pointsBulb protector protects against impact, easily remove to rinse probeIP67-rated housing is waterproof, dustproof, and floats in water when sensor cap is on Specifications Min/Max pH -2/16 pH Resolution 0.01 Buffer Recognition NIST and USA Calibration Up to 3 points Min/Max Temperature (° C) 0/50 Min/Max Temperature (° F) 32/122 Temperature Resolution 0.1 Temperature Accuracy (° C) 0.5 Temperature Accuracy (° F) 0.9 Battery life (hr) 500 Diameter (in) 1.5