Oakton EcoTestr Waterproof pH Meter
Push button 3 point calibration, Automatic Temperature Correction (ATC). Transparent, protective cap keeps sensor moist when stored upright, and used as container for sensor conditioning or on-site calibration. Waterproof, dustproof housing is Ingress Protection (IP) 67-rated, for protection against solid objects or liquids. Large, upright, single-line LCD display screen for ease of viewing, and for display of indicators
You can use a pH meter to check the pH of your water, mash, [test Star San effectiveness] and finished beer.
Oakton EcoTestr pH 2 Waterproof pH Tester, 0.0 to 14.0 pH Range