The Orion 3-Star waterproof, battery-operated pH meter from Pulse Instruments stands up to the most demanding field applications and delivers more than 2,000 hours of continuous operation. A convenient quick-start guide is located on the back of the meter to make the unit easy to operate in the field. Featuring automatic or 1- to 5-point manual calibration, the rugged meter offers a full complement of GLP-related features. Record and store up to 10 setup parameters and calibrations -- a valuable feature for fast measurements in the field. Download additional methods and software updates via the Web. Three-year replacement warranty.