Proportional pH and ORP Control in a Single Wall Mounted Unit - 115VAC - * Two separate setpoints can be user-adjusted * Two independent terminals provide for pH and ORP ground probes * Accepts any pH and/ or ORP electrode ending in a universal BNC connector HI 9912-1 is a 2-in-1 pH and ORP controller specially designed for pool control. Two separate setpoints can be user-adjusted from 6 to 8 pH and 500 to 900 mV. The relays are activated when the pH exceeds or the mV falls below the relevant setpoint. HI 9912-1 accepts any pH and ORP electrode ending in a universal BNC connector. Two independent terminals provide for pH and ORP ground probes to eliminate interference and prolong the electrodes’ lives. HANNA instruments® proportional control allows considerable savings by minimizing the use of chemicals. The settings are made through independent time cycles adjustable from 0 to 90 seconds and two proportional bands from 0 to 200 mV and 0 to 2 pH. Two pumps or electro-valves can be wired directly to the controller and be powered through the terminal. HI 9912-1' s alarm is activated when measurements exceed the operatoradjustable thresholds of 50 to 250 mV or 0.5 to 2.5 pH. Should the two max. dosing periods of 1 to 10 minutes be exceeded an alarm is activated to signal the abnormality. The alarm is alterable in a normally-closed or a normally- open state and can be turned off during maintenance. The pools status can be ascertained from a distance through dosage and alarm LED’ s. HI 9912-1 comes with extractable terminal modules for quicker and safer wiring. The wiring compartment is protected behind a fire-retardant ABS removable panel. HI 9912-1 is supplied complete with instructions.