TSS Sensor

Whatever level of suspended solids from 2 NTU all the way up to >8% solids, the Chemtrac TSS Monitor is the solution. A sophisticated sensor that ranges up to 8% solids (in wastewater, and up to 50% in other solids), this suspended solids monitor is the solution, and is unique in its ability to measure from low NTU to percent solids in one sensor.

Suitable for wastewater, potable water monitoring, mixed liquor suspended solids monitoring, return activated sludge, centrate monitoring, filtrate monitoring, sludge, and many more applications where a traditional turbidimeter or suspended solids analyzer would be used. The suspended solids sensor can be fitted with an auto-cleaning function that blasts either water or air across the optical windows keeping them clean.

With the Chemtrac Suspended Solids monitors you get a world class sensor (patent applied for).


  • Applications

    The suspended solids analyzer has been designed specifically to be suitable for all wastewater applications.

    Inlet monitoring (turbidity 2-4,000 NTU)
    Effluent monitoring (suspended solids 0-1,000 mg/l)
    Traditional monitoring applications where the TSS monitor is particularly suited:

    • Online Suspended Solids Analyzer
    • Online RAS meter (Return Activated Sludge)
    • Online MLSS meter (Mixed Liquor Suspended Solids)
    • Online WAS meter (Waste Activated Sludge)
    • Thickened sludge – Online total suspended solids meter
    • Centrate – Online total suspended solids meter
    • Filtrate – Online total suspended solids meter
    • Wastewater Effluent – Online total suspended solids meter
    • Wastewater Influent – Online total suspended solids meter for turbidity
    • Each probe is equipped with a light source and 2 detectors. The light source is a long-life infra-red LED emitter (providing for 15 years working life).

    By using two detectors in a single probe it is possible to:

    • Measure Turbidity from 2 NTU to 4000 NTU.
    • Measure solids from 0.001 NTU to 80 g/l (8% solids) – Sludge
    • Measure solids from 0.001 to 500g/l (50% solids) – Silicates

    The electronics provide a fully scalable output allowing the TSS analyzer to measure any part or the whole of the scale. The sensor probe comes equipped with the capability of having a water jet regularly sweep over the optical lenses keeping them clean. If you have an application that ranges from low NTU all the way to % solids then this is certainly the suspended solids monitor for you! With up to 5 calibration points you can accurately monitor your process across a wide range of sample concentrations.

    The probes are constructed of 316 stainless steel with sapphire optical windows, so they can withstand demanding operating environments. If you want to monitor solids at any point in your wastewater treatment plant, this instrument has the self-cleaning sensor and accessories to do it, even if other instruments have failed.

  • Specifications

    Range: Up to 500 g/l, 4000 NTU (depending on the optical properties of the sample
    Units: Selectable g/l, mg/l, ppm, ppt, % (suspended solids), or NTU or FNU (turbidity)
    Accuracy: < 2% of measured value or 0.01 g/l or 0.8 NTU (whichever is greater)
    Reproducibility: < 1% of measuring value or 0.001 g/l or 0.8 NTU (whichever is greater)
    Limit of Detection: 0.001 g/l or 2.4 NTU
    Resolution: Up to 0.0001 g/L
    Response Time: T90 > 10 sec (adjustable based on averaging
    Drift (electronic): None
    Averaging: Configurable (10 sec – 10 min)
    Lamp Source: IR LED (860nm)
    Weight: Approx. 1 kg (35 oz.)
    Process Temperature: 0-50o C (32-122o F)
    Operating Pressure: 10 bar (145 psi) maximum
    IP Rating: IP68
    Mounting Thread (for dip installation): 1” BSP
    Max. Power Consumption: 70 mA at 15 VDC
    Cable Length: 6m (20 ft) standard (extendable by request)
    Wetted Parts: 316 stainless steel, sapphire
    Diameter: 38mm (1.49”)
    Length: 230mm (9.06”)
  • Description

    Each suspended solids monitor is fitted with a light source and two detectors for making the measurements. Having two detectors, positioned at different distances from the light source, allows the sensor to be used over a wide range of suspended solids concentrations. The light source is a long life infra-red LED emitter (providing for 15 years working life). The detectors are matched photodiodes that are positioned to detect backscattered light, which is light that is scattered by >90°. By measuring back scattered light the sensor can be used to detect low and high concentrations of solids. This configuration allows accurate and reliable measurements of suspended solids concentrations and turbidity to be made.

    Calibration of the TSS sensor for turbidity measurements (NTU) or measurements of samples with low concentrations of solids is very easy, requiring a single calibration sample. This sample can either be a reading from another method, or a suitable standard. The analyzer calibrates the sensor by a procedure that reduces the light output through four stages, taking measurements at each. This process provides an accurate and reliable zero and span without the requirement to use a ‘0’ NTU/solids sample.

    The calibration of the TSS sensor for the measurement of samples with high concentrations of solids uses a multi-point calibration for the most accurate results. Up to 5 calibration points can be used to give an accurate performance across a wide range of sample concentrations.

    The TSS sensor can be mounted on the end of a pole for dip mounting in a channel or tank, or inserted into a pipe via a valve which allows for retraction/removal of the sensor without shutting down the process.

    Standard Features

    • From 2 NTU to 8% Solids
    • Displays in NTU, mg/l, g/l or % solids – flexible

    Optional Features

    • Auto-clean optical sensor – months without maintenance
    • Dip mount for a channel or tank
    • Pipe insertion mount


    • Stable and reliable – excellent process control
    • Suitable for potable, waste and process waters
    • Up to 12 months between maintenance
    • Up to 12 months between calibration

    More Benefits

    The Chemtrac suspended solids sensor is available with different controllers giving you the same great performance with different communication, display, and control options. With the Chemtrac range of online suspended solids analyzers, you get everything that you need – and nothing that you don’t, without sacrificing the quality of measurement.

    The use of a single sensor to robustly and accurately measure a large dynamic range of suspended solids allows for:

    • Less spares – more commonality across a single or multiple sites
    • No requirement to know the range prior to specifying – easier purchasing
    • One online suspended solids analyzer can be:
      • Online mlss meter
      • Online tss meter
      • Online total suspended solids meter
      • Online effluent monitor
      • Online inlet monitor
      • Online ‘in process’ suspended solids analyzer
  • Downloads

Connect With Us

Call Us

800.442.8722 or 770.449.6233

Meet Us

1555 Oakbrook Drive
Suite 100
Norcross, GA 30093