HI 981402 is a water-resistant pH meter with a built-in 3½ digital LCD. The meter is supplied with the HI 1286 double-junction, plastic-body, gel-filled combination pH electrode with a flexible 2 meter (6.6') cable. The BNC connector is protected by a waterproof sheath. The electrode also has a unique clog-resistant Teflon® diaphragm that enhances both probe life and accuracy.The alarm set point can be selected anywhere in the 3 to 11 pH range. A red LED warns the user in the event the reading is outside the set point by more than ±0.5 pH. Calibration can be manually performed at 1 or 2 points through two easily accessible trimmers on the front of the unit.The meter is suited for outdoor installations and highly humid environments. The casing has been specifically designed to sit out of the way and provide maximum stability while preventing rolling from any surface. In addition, the molded keyhole holder allows the meter to be installed close to the sample. The 12 Vdc power supply is ideal for continuous monitoring over extended periods of time.