Hanna Instruments HI 504 pH/ORP Panel Controller with Relays

The Hanna Instruments HI 504 is a new, panel-mount pH/ORP microprocessor-based controller designed for continuous industrial process monitoring and control. The front panel features an LCD display, six membrane keypad buttons (LCD, CAL DATA, SETUP, CAL, Up/Down navigation, and CFM/confirm), four LED status indicators, and four relay contact indicators — all visible in the provided photos. The rear terminal block assembly includes multiple screw-terminal connectors for electrode input (with BNC-style coaxial connection), temperature compensation input, relay outputs, and analog outputs, along with a yellow cautionary label specifying that the differential input matching pin must be connected to the electrode reference terminal before use. The unit ships with panel-mount hardware consisting of three sets of L-bracket mounting clips and threaded rods (visible in the accessory photos) for standard cutout panel installation. The HI 504 is manufactured in Romania (visible on rear label) and is suited for water treatment, chemical dosing, and industrial process pH/ORP monitoring applications where relay-based setpoint control is required.

Product Specifications