Overview
The HI8720 is a compact panel-mounted Online Continuous Oxidation Reduction (ORP) controller with a Measurement range of +/- 1000mV. It features a large LCD display with protective cover and backlight, supports a single set point and output for oxidation or reduction dosing settings, manually calibrates two points via panel, and provides isolated Analog Output (0-20 mA or 4-20 mA). Optional manual ON, OFF and automatic Basis Weight control for oxidation or reduction of Basis Weight dosing settings; automatic diagnostic functions verify offset and slope calibrating and Electrode contamination or failure, and fail-safe alarm systems prevent problems due to power failure or signal interruption.
Features
1. Compact panel mounting design makes it easy to continuously detect ORP online.
2. Large LCD display with protective cover and background light for clear display.
3. Single set point and output, support oxidation or reduction dosing settings.
4. Manual two-point Adjustment, easy to operate.
5. Isolated Analog Output: 0-20 mA or 4-20 mA.
6. Select manual ON, OFF and automatic Basis Weight control modes.
7. Automatic diagnostic function to verify offset, slope calibrating and Electrode status.
8. Failure-safe alarm system to prevent power or signal problems.
9. High Input Impedance (10 ^ 12 Ohm), compatible with BNC interface Electrode.
Principle
The HI8720 controller is connected to ORP Electrode via a BNC interface, measurement Oxidation-reduction potential (range +/- 1000mV), input Impedance up to 10 ^ 12 Ohm to ensure accuracy. It uses a manual two-point calibrate mode, fine-tuning the drift through the panel knob （ +/- 200 mV), and controls dosing relays (max 2A, 240 VAC) based on a set point for oxidation or reduction dosing. The Analog Output provides an isolated current signal (0-20 mA or 4-20 mA), supports automatic diagnostic functions to detect Electrode contamination or failure, and a fail-safe alarm system to handle anomalies.
Applications
Online Oxidation-reduction potential monitoring, industrial dosing control, water quality treatment, chemical process control, environment monitoring
Steps
1. Install the controller on the panel to ensure that the opening size is 141 * 69mm.
2. Connect the power supply (230AC +/- 10%, 50/60 Hz).
3. Connect ORP Electrode through the BNC interface.
4. Use the panel knob for manual two-point calibrating, fine-tuning drift +/- 200mV.
5. Set the dosing relay setting point (range +/- 1000mV) and the alarm relay setting point (range 10-300 mV).
6. Select the dosing control mode: manual switch OFF/AUTO/ON.
7. Adjust the control delay time (5-60 minutes) or turn off this function through the rear panel terminals.
8. Configure Analog Output to 0-20 mA or 4-20 mA.
9. Turn on the background light (continue to turn on), and start monitoring and dosing control.
Notice
* Power supply voltage is 230AC +/- 10% to avoid over-range use.
* Operating ambient temperature range is -10~ 50 ℃, relative humidity 95% non-condensing.
* Use the matching BNC interface ORP Electrode to maintain Measurement accuracy.
* Dosing relay maximum load 2A (240 VAC), do not overload.
Alarm relay setting range 10-300 mV, set reasonably to prevent false alarms.
The control delay time is adjustable, and attention should be paid to setting it according to actual needs.
* Analog Output is isolated type, properly wired to avoid interference.
* Periodically perform automated diagnostics to check Electrode status and calibrate.
* Avoid long-term use in humid or condensing environments to prevent damage.
When installing, ensure that the shell ABS flame retardant plastic is intact and the front cover is splash-proof.
