The HI 21 & HI 22 series are wall-mounted, microprocessor-based pH and ORP controllers. This manual provides basic information on the operation of these controllers.
The document serves as an instruction manual for the HI 21 (pH) and HI 22 (ORP) Series wall-mounted, microprocessor-based controllers. It details functional descriptions, mechanical dimensions, and specifications including measurement ranges, accuracy, analog outputs, and relay capabilities.
The guide covers comprehensive operational procedures such as preliminary examination, installation steps for power and electrodes, setup mode configuration using passwords, control modes (ON/OFF, proportional, PID), calibration processes with specific buffer values, fault conditions, self-test procedures, and electrode conditioning.
| Measurement Range (pH) | 0.00 to 14.00 pH |
|---|---|
| Measurement Range (ORP) | ±2000 mV |
| Resolution (pH) | 0.01 pH |
| Accuracy (pH) | ±0.02 pH (@20°C/68°F) |
| Relay Capacity | 5A-250 Vac, 5A - 30 Vdc |
| Operating Environment Temperature | 0 to 50°C (32 to 122°F) |
The HI 21 series allows calibration at 1, 2, or 3 points using pH 4.01, 7.01, and 10.01 buffers.
The HI 22 series allows calibration in 1 or 2 points at 0, 350, and 1900 mV.
Press the SETUP key to enter the setup mode, then enter the password when prompted.
They use electromechanical relays with SPDT contact outputs.