HI 9920: ORP Proportional Control, Single Setpoint, Wall Mount

• Single setpoint for user-selectable dosage of reducing or oxidizing solutions
• Interchangeable BNC electrodes
• Alarm relay

HI 9920 is an ORP controller with a single setpoint for user-selectable dosage of reducing or oxidizing solutions. Any ORP electrode ending in a BNC connector can be directly attached to the controller. With proportional control, you can fine tune your treatment plant and minimize the use of chemicals. The proportional setting can be adjusted through the time cycle from 0 to 90 seconds and the band from 0 to 200 mV. The setpoint can be accurately adjusted through coarse and fine trimmers. A pump or electro-valve can be wired directly to the controller and be powered through the terminal. In addition to the setpoint relay, HI 9920 also provides for an alarm relay. The alarm is activated when the measurements exceed the operator-adjustable threshold of 50 to 250 mV. For extra security, a maximum dosing time from 1 to 10 minutes can also be set, after which the alarm is activated to signal an abnormality. The alarm configuration is alterable in a normally-closed or a normally-open state to accommodate fail-safe installations. Any recorder accepting a 0-20 or 4-20 mA output can also be hooked up to the controller. One can see the controller's status, even form a distance, by observing the dosage or alarm LED's. To speed up wiring, HI 9920 comes with extractable terminal modules. Once wired up, the compartment containing the connections is protected behind a fire retardant ABS removable panel. HI 9920 also provides for a ground probe to eliminate interference and prolong the electrode's life.

HI 9920 is supplied complete with instructions.