ORP57 has a stability indicator and hold function that freezes the display for easy and accurate recording. IP65 Waterproof pH tester with Large dual-level LCD that displays ORP and temperature (°C or °F). The large display shows readings from -1000 to +1000 (with a resolution of 1 mV) and simultaneously shows temperature from -5.0 to 105.0°C or 23.0 to 221.0°F. ORP57 has a...