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HI 9920 is an ORP controller with a single set point for user-selectable dosage of reducing or oxidizing solutions.


£690.20 (exc.VAT)
£828.24 (tax incl.)
Order now for 2 weeks delivery
Full Description Specification

Industrial grade ORP controller with proportional dosage

The HI 9920 is an ORP controller with a single set point for user selectable dosage of reducing or oxidising 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 minimise 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 set point 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 set point relay, the 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 from set point. 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 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. Users can see the controller's status, even from 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.

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Range - mV-500 to +1500 mV
Resolution 1 mV
Accuracy ±5 mV
Input Impedance 1012 Ohm
Calibration manual, 1 point, through trimmers on the front panel
Recorder Output selectable at 0-20 mA or 4-20 mA (isolated)
Setpoint selectable from -500 to +1500 mV
Proportional Control adjustable from 0 to 200 mV and time cycle from 0 to 90 seconds
Dosing Contact 1 powered terminal for ORP correction (115 or 240 V) Max. 2A, 1,000,000 strokes;
activated when mV reading > setpoint for reducing dosage
or when mV reading < setpoint for oxidizing dosage
Alarm Relay 1, activated when mV reading varies more than a selectable value (50 to 250 mV) from setpoint
or when max dosage time (adjustable from 1 to 10 minutes) elapses
(isolated, Max 2A-240 V, resistive load, 1,000,000 strokes)
Power Supply 110/115 Vac ±10% or 220/240 Vac ±10%; 50/60 Hz
Environment -10 to 50° (14 to 122°F); RH max 95% non-condensing
Dimensions 221 x 181 x 86 mm (8.7 x 7.1 x 3.4")
Weight 1.6 kg (3.5 lb.)