HI 98127 and HI 98128 are waterproof pH and temperature meters. The housing has been completely sealed against humidity and designed to float. All pH readings are automatically temperature compensated (ATC), and temperature values can be displayed in °C or °F units. The meters can be calibrated at one or two points with auto-buffer recognition and against five memorized buffer values. Measurements are highly accurate with a unique stability indicator right on the LCD. A low battery symbol warns the user when the batteries are to be replaced. In addition the Battery Error Prevention System (BEPS) avoids erroneous reading caused by low voltage level by turning the meter off. The HI 73127 pH electrode, supplied with the meters, is interchangeable and can be easily replaced by the user.