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Turbidity Controller for the precision measurement and control of turbidity


Turbidity Controller

A Turbidity controller is a device designed to be permanently installed as either a stand alone instrument, or as part of a control panel - to offer continuous turbidity measurements from a Turbidity Sensor.

Turbidity instruments with control functionality such as relays and current outputs are designated controllers as they are able to ensure that not only is the Turbidity levels are accurately monitored, but that equipment can be controlled based on the turbidity value.

Our Turbidity controllers ensure that the control relays can be switch via 2 set-points within the controller. These are idea for controlling waste water treatment processes, aquaculture processes, and for controlling valves and alarms for effluent or water treatment processes.

Turbidity Control Options

Where final effluent discharge is being monitored in accordance with a consent to discharge agreement from the environment agency, it is essential that the outflow is accurately monitored to ensure compliance.

If the turbidity is above a designated value then the effluent monitoring turbidity controller would be able to call for an alarm condition, and  / or stop control a valve to stop the discharge or the process.

The turbidity controllers are supplied with a number of set-points for control purposes, which can work directly with control equipment such as valves and pumps. Alternatively our turbidity controllers can be integrated into an existing control panel or system. The control set-points and corresponding relays can be used to close a valve or stop a process should the turbidity value be out of specification. In addition - an alarm relay can be used to alert an operator to the turbidity being out of specification.

The turbidity set-points correspond to the measuring range, so where turbidity monitoring for effluent discharge inline with a consent to discharge agreement is a fairly common application, our turbidity controller range are equally at home monitoring drinking water applications for water quality analysis, and in aquaculture applications where algae, soil wash and discharge into rivers can affect both commercial and environmental activities.

Turbidity Controllers and Turbidity Sensors

Our Turbidity controller is designed to work with our TU810 to TU8182 Turbidity sensors which use the nephelometric turbidity measurement methodology measuring the 90° back scattering to ascertain the turbidity value.

The Turbidity sensors connect directly to the turbidity controllers which provides a number of benefits over using a turbidity transmitter. Primarily it allows the turbidity controller to re-range the turbidity sensor - which when combined with the TU810 or TU8182 sensor - it allows the measuring range to change from 0 - 4.000 NTU, 0 - 40,00 NTU or 0 - 400.0 NTU as required.

In addition the turbidity controllers include an auto-clean relay which allows a compressed air system to use an air blast to clean the turbidity sensor lens. When the lens is being cleaned the Turbidity Controllers can activate their freeze and hold functionality, which prevents the set-points being activated, and freezes the current value on the turbidity controller.

Finally - the turbidity controllers include a 4-20mA output which can be configured to work with digital chart recorders or data loggers to allow the historic turbidity values to be logged.

Turbidity Controller Range



The TU7685 is a panel mounting turbidity controller designed to work with our TU8182 or TU800 turbidity sensor.

The TU7685 has user selectable ranges of

  • 0 - 4.000 NTU
  • 0 - 40.00 NTU
  • 0 - 400.0 NTU

A full suite of control options are available on the TU7685 including 2 x control relays, alarm relay, auto-clean relay with Freeze & Hold functionality, and isolated 4-20mA output.

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