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Dissolved Oxygen Controller with 4-20mA output

Dissolved Oxygen Controller OD7635 with 4-20mA output

Panel Mounted Dissolved Oxygen Controller with a 2 x Control Relays and Isolated 4-20mA Output

The OD7635 Dissolved Oxygen Controller is available in either surface mounting or panel mounting configuration.

OD7635 Dissolved Oxygen Controller Introduction

The OD7635 Dissolved Oxygen Controller is a panel mounting Dissolved Oxygen controller with a large bright red LED digital display in a DIN spec. housing 96 x 96mm and is designed for the DN 47300 standard. This instrument also has a very short case length at only 95mm, allowing the controller to be mounted into compact sized control panels saving on both space and cost.

The easy to use OD7635 Dissolved Oxygen Controller has 8 buttons located on the front for easy access to the setup, configuration and calibration areas of the software. This allows the instrument to be easily setup and configured and makes periodic calibration a simple process with the dedicated Zero and Sensitivity calibration buttons.

To ease the installation of the OD7635 Dissolved Oxygen Controller the instrument is fitted with a switch mode power supply, suitable for a supply voltage of 86-264 VAC 50 / 60Hz.

The OD7635 Dissolved Oxygen Controller includes 2 x control relays for use in either High or Low operation and has a user configurable alarm relay which is operated when the Dissolved Oxygen reading is outside of parameter.

In addition, the OD7635 has a 4-20mA output isolated to 600Ω, making it ideal for incorporation into BMS or PLC systems, as well as with an online Data Logger or with a digital Chart Recorder.

The OD7635 is designed to work with either a Polarographic Dissolved Oxygen Sensor such as our model DES-1 or with a Galvanic Dissolved Oxygen Cell.

OD7635 Dissolved Oxygen Ranges

The OD7635 Dissolved Oxygen controller is able to measure both saturation and concentration of dissolved oxygen.  The ranges are as follows:-

Dissolved Oxygen Measuring RangeResolution
0 - 200.0% (Saturation) 0.1%
0 - 20.00 mg/L (concentration) 0.01 mg/L

OD7635 Dissolved Oxygen Controller Automatic Compensation

The OD7635 is a very sophisticated dissolved oxygen controller offering automatic compensation of the dissolved oxygen value against the following environmental influences:-

  • Automatic Salinity Compensation
  • Automatic Barometric Pressure Compensation
  • Automatic Relative Humidity Compensation 
  • Automatic Temperature Compensation

The Automatic Salinity compensation allows the instrument to adjust the concentration measurement (mg/L) according to the user input of the PPT of the chloride concentration of the sample. The automatic temperature compensation has a user selectable co-efficient with default setting 2.3% with a range between 0-4.00 % per °C.

Please contact us if you require any specific information about this element of the operation of the OD7635 dissolved oxygen controller.

OD7635 Dissolved Oxygen Controller with 4-20mA Output

The Od7635 has an industry standard 4-20mA output which correlates to the user selectable ranges. This ensures that the 4-20mA will give an accurate output corresponding to the range, with 4mA at the lowest point, and 20mA at the top of the selected range.

The 4-20mA output is isolated into 600Ω so that it is incredibly easy to connect to a PLC, Online Data Logger, digital Chart Recorder or other device.

OD7635 Dissolved Oxygen Controller with Control Relays

The front panel of the OD7635 includes 8 keys that allow simple navigation of the panel mounted dissolved oxygen controllers options.  The Zero and Span for the calibration procedure are mounted on to the front of the controller.  In addition both set-points are identified with their own front mounted button, allowing their values to be easily changed.

The dedicated Up / Down arrows on the front of the controller allow for easy modification of either the calibration or set-point values, decreasing initial setup time or the time spent during periodic calibration or maintenance.

The 2 x set-points control 2 x control relays which can be set to High or Low operation independently.  Each of the control relays include a variable hysteresis and a delay timer which can be set from 0-100 seconds.

In addition to the control relays, the OD7635 has a user configurable alarm relay which is energised when the dissolved oxygen value is outside the set parameters.  It has an easy set up feature and the operator has the ability to access the most frequently used functions.

There is also a logic input on the OD7635 which takes a volt free contact closure input.  When activated, the logic input isolates the output relays, preventing them from energising.  The Logic Input can be connected directly to the alarm relay if required.

OD7635 Easy to Operate Dissolved Oxygen Controller

The OD7635 is a simple to use Dissolved Oxygen controller.

In addition there is a password locked configuration screen which allows the user to change the less frequently adjusted settings.

For routine calibration of the instrument, the Zero and Span of the instrument are easily adjustable from the main menu, with a quick and easy menu driven calibration procedure.

The measuring range in mg/L or % is clearly visible on the front panel of the instrument, as is the current status of the set-point 1 relay, and the set-point 2 relay.  In addition the alarm relay status is clearly visible from the front of the instrument as is the logic input status.

The versatility of the microprocessor, accompanied with the user friendly software, allows the programming of the functions, routine checks and calibration to easily be accomplished, even by untrained operators.  Installation of the 7635 series of instruments is intended to be into a control panel or in the optional surface mounting enclosure.

OD7635 Dissolved Oxygen Controller Specifications

  • Specifications


    Model No:- OD7635

    Dissolved Oxygen Saturation Range:- 0-200.0%

    Dissolved Oxygen Saturation Resolution:- 0-0.1%

    Dissolved Oxygen Concentration Range:- 0-20.00mg/L

    Dissolved Oxygen Saturation Resolution:- 0-0.01mg/L

    Supported DO Probes:- Polarographic (Clarke) Sensor or Galvanic Sensor

    Temp. Compensation:- 0-4.0% base 20ºC

    Temp. Compenstation Range:- 0ºC to 50ºC

    Set Points:- 2 Min / Max selectable, contact SPST, 5 Amp inductive

    Action:- On / Off with delay timer of 0-100 secs

    Current output:- 0-20/ 4-20mA isolated into 600Ω

    Zero:- ±10% air at 20°C

    Slope:- 50% / 200%

    Mains Supply:- 85 - 264 Volt, 50 / 60Hz switch mode power supply

    Power Consumption:- 6 VA

    Weight:- 400 grams DIN version

    Dimensions:- 96 x 96 x 95mm cutout 92 x 92mm

  • Features


    • Panel mounting Dissolved Oxygen controller for fitting into control panels or for use in a surface mounting enclosure.
    • Precision Dissolved Oxygen monitoring for process and effluent applications. Ideally suited for environmental monitoring of effluent discharge, or for boiler feed water.
    • Easy to setup, install and use
    • Bright display suitable for use even in bright sunlight.
    • Two control relays and an alarm relay with easy to configure set-points.
    • Alarm relay which is engaged when the dissolved oxygen value is out of parameter (e.g. above and below a desired range) which can be linked into the logic input.
    • Isolated 4-20mA current output isolated into 600Ω, which is ideal for data-logging or connecting to a PLC.
  • Data Sheets

    Data Sheets


More Information