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Submersion Turbidity Transmitter

Submersible Turbidity Transmitter for Dirty Water

The TU8355 is a Turbidity Sensor with integrated electronics designed to output a 4-20mA signal, proportional to the turbidity measurement. The TU8355 is designed to be screwed into a riser tube for submersion into streams, weirs, pits, tanks or other unpressurised vessels.

The TU8355 uses an infrared light emitting source and a 90° photo-receptor to measure back scattering to give precision turbidity measurements in FTU (Formazine Turbidity Units).

Manufactured in PVC with an IP68 rating, the TU8355 is designed to be submersed into an open vessel, stream or pit to give continuous turbidity measurements.

4-20mA Submersion Turbidity Transmitter

The TU8355 is a unique piece of equipment. It combines a back-scattering turbidity sensor complete with integrated electronics to provide an isolated 4-20mA output, proportional to the turbidity measurement.

The industry standard 4-20mA output signal is isolated into 600Ω and designed to give easy integration with a wide range of control equipment. The 4-20mA signal is simple to connect to a PLC, digital Chart Recorder, universal controller or even our online Data Logger.

The 4-20mA output is loop powered, which means that the same two wires which carry the 4-20mA signal are also the same two wires which power the device. This makes integration with PLC's and other control equipment incredibly straightforward.

Turbidity Transmitter - FTU Ranges

The TU8355 is designed for water quality analysis and is suitable for drinking water applications, raw water applications and water treatment applications. The ranges available with the TU8355 are as follows:-

Turbidity Ranges and Resolutions
  Turbidity Range (Nephelometric Turbidity Units)
 0 - 100.0 NTU
  0 - 1000 NTU
  0 - 10,000 NTU

As a microprocessor driven device, the TU8355 can communicate with a personal computer using a hyper-terminal client and serial interface. By accessing the device the ranges can be adjusted in the instrument software, allowing the same device to measure up to as high as 10,000 FTU.

We're also able to factory calibrate the measuring range of the instrument prior to it being despatched.

The TU8355 also offers a digital RS485 output which can be used to connect to a supported device.

Submersion Turbidity Transmitter

The TU8355 has a 2" thread at the rear of the device to allow it to screwed into a riser tube (such as our model TU90s or TU90-ATC-S) for continuous or online turbidity measurements.

Designed to continuously monitor the turbidity in a stream or tank, the TU8355 is used in applications such as water treatment monitoring, raw water monitoring and other water quality analysis in industrial or municipal environments.

In addition to the rear mounting thread, the TU8355 has an optional auto-clean nozzle, which can be connected to a suitable compressed air system.  The auto-clean system can be called for via a PLC or an auto-clean relay from of our universal controllers: (BC7635-AC or BC7685-AC). The auto-clean system then uses the compressed air to remove any contaminating agent or detritus from interfering with the lens of the turbidity transmitter, thus reducing the requirement for human involvement in preventative maintenance and prolonging continuous operation.

The auto-clean air-nozzle is rated for use with a maximum air pressure of 3 Bar.

Submersible Turbidity Transmitter Features & Benefits

The TU8355 is a genuinely unique instrument.  Designed to be permanently mounted into the flow of a weir, stream or into an open tank and provide continuous turbidity readings and outputs with a 4-20mA signal, proportional to the turbidity measurement.

Designed to offer precision measurements even when measuring very high turbidities, the TU8355 can measure as high as 0-10,000 FTU or across a low range down to 0-100 FTU for additional granularity at low ranges. Using a personal computer hyper terminal, the serial interface allows the range to be changed from 0-100 FTU, 0-1000 FTU or 0-10,000 FTU.

The PVC body and IP68 rating allow the cell to be permanently mounted into a dip tube or riser tube and with the optional auto-clean system enabled, gives continuous turbidity readings with minimal maintenance.  The isolated industry standard 4-20mA can interface with a wide arrange of PLC's and other control instruments, which can be easily connected using just 2 wires.

The turbidity measurements follow the back scattering methodology and the infra-red light is not affected by the colour of the sample.

The TU8355 also offers a digital RS485 output which can be used to connect to a supported device.

TU8355 Submersion Transmitter Specifications

  • Specifications


    Submersible High Range Turbidity Transmitter

    Model No:- TU8355

    Turbidity Range:- 0-100 FTU

    Turbidity Range:- 0-1000 FTU

    Turbidity Range:- 0-10,000 FTU

    Zero NTU:- ±10 FTU all ranges.

    Sensitivity:- 70% / 130%

    Materials and Rating:- Manufactured in PVC to IP68

    Analogue Output:- 4-20mA isolated into 600Ω

    Digital Output:- RS485

    Operating temperature:- 0-50°C

    Operating Pressure:- 1 Bar at 25°C

    Power supply:- 9 / 36 VDC

    Weight:- 800 grams

  • Features


    • Submersion Turbidity Sensor for installation into riser tube, which allows the TU8355 to give to continous or online Turbidity measurements from inside a tank, pit, weir, stream or other unpressurised vessel.
    • Ideal for applications with a high propensity of total suspended solids, such as waste water aeration systems or aquaculture monitoring.
    • Exceptional accuracy even at very high ranges, a maximum upper range of 10,000 FTU all in the same compact design.
    • Simple to install and connect to measurement and control equipment - the 4-20mA current output is loop powered, meaning that the same two wires that transmit the signal also transmit the measurement signal.
    • Optional auto-clean nozzle, means that when paired with a suitable auto-clean system, and build up of material around the sensing lens of the TU8355 can be removed, reducing the requirement for human intervention outside scheduled preventative maintenance.
    • The TU8355 has no moving parts and requires minimal periodic calibration and maintenance.
    • Factory set or configurable via computer - the TU8355 can be periodically calibrated using a personal compute and the instrument can be re-ranged for alternative applications as required.
    • Designed specifically for precision measurements in waste water aerators, in aquaculture monitoring and effluent treatment monitoring applications.
  • Data Sheets

    Data Sheets


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