The BL-121 Swimming Pool Controller is a complete system designed for maintaining swimming pool, hot tub, and spa disinfection water quality. The BL-121 is available in two configurations: the basic version (BL-121-10) is the in-line model which allows for direct installation of probe and chemical injection fittings into existing piping, and the other version (BL-121-20) is a panel mounted version with a bypass flow cell.
The bypass flow cell allows for calibration and maintenance of the probe without having to shut down the recirculation pump. Additional features of the BL-121 include LED indicators for dosing, meter status and service, real-time graph display, programmable alarms, and password protection.
The HI-1036-1802 is a digital probe that measures pH, ORP, and temperature. This probe also incorporates a potential matching pin. The pin is considered the “earth ground” connection and is used to prevent ground loop effects from causing erratic readings and damage to the system.