Harvard Apparatus, Inc., Holliston, MA, offers a waterproof handheld pH meter that measures both pH and temperature. The microprocessor-controlled device has a rugged, waterproof casing and its Auto-Instruction feature guides you through calibration, including NIST buffer calibration at 6.86 and 9.18 as well as the standard 4.01, 7.01, and 10.01. Other features include 1- or 2-point calibration with any of the memorized buffers, a ready symbol for when the unit has stabilized, and automatic shut-off. The dual-level display shows pH or mV as well as temperature to 0.1°C.
Harvard Apparatus, Inc.