Suspended Solids

Browse our sub categories

  • Suspended Solids

Suspended Solids

The New Zealand Dairy Industry wanted a sensor that:
Did not drift or leak and contained no glass
Could be calibrated on site to give meaningful outputs for the operators
Could be optimised for different solids concentrations. 

Quadbeam sensors were developed to meet those demands, using the multi-beam ratio-metric self compensating system to compensate for contamination and ageing of sensors (Four Beam Technology). The S Series sensors are manufactured from a polymer block eliminating glass and the chance of leakage at the same time. A simple multi point calibration system has been used to ensure that the sensors can be calibrated on site against meaningful site standards and site lab equipment. 

Control of the waste and returned activated sludge flows in Wastewater Treatment Plants allows operators to improve treatment rates, save energy and ensure discharge compliance. This process can be greatly improved by measurement of the solids content of the sludge being returned.
RAS measurement will ensure that the solids being returned to the activated sludge plant are in the right concentration range. Traditional methods of setting return rates rely on flow rates, typically the inlet flow which due to retention times can be hours out of sync with the activated sludge plant.

Using Suspended Solids as a control parameter keeps the activated sludge plant working at its optimum efficiency, with the RAS pumps reacting the solids loading not the flowrate.

The Partech TurbiTechw² LA Sensor has been designed for use in aeration systems monitoring suspended solids also known as mixed liquor suspended solids or activated sludge where solids are typically in the range of 1,500 to 3,500 mg/l.

The TurbiTechw² cleaning mechanism uses a polyurethane wiper seal, sealed by 2 Nitrile ‘H’ Rings that finish the cleaning process. The Nitrile seals can be exchanged for Viton if the process media dictates.

Read more here

View Product


Phathom turbidity sensors offer reliable, accurate, continuous monitoring in environmental applications.

Phathom turbidity and TSS sensors provide sophisticated multi-beam technology in a rugged, durable package. Phathom’s self-compensating algorithms correct for measurement errors that other sensors can’t handle so you get real-time information, all the time.

Phathom sensors generate multiple alternating beams of light to create a ratio-metric algorithm

Each Phathom sensor has two LED light sources and two light detectors. LED 1 switches on and the light is picked up by detector 1 and detector 2. Then LED 1 switches off and LED 2 switches on. Again, the light is picked up by detector 1 and detector 2.

This array creates multiple beams of light—four in total—which can provide a measurement of light transmission and scatter as they pass through the water.

The magic happens when these multiple beams are synthesized into a ratio-metric algorithm that, once calibrated, precisely calculates turbidity and total suspended solids.

You can integrate a Phathom sensor into your existing telemetry through either a 4-20mA, Modbus RS485 or SDI-12 connector.
Or connect directly to a cloud-based Internet of Things transmitter.  See the PingAlert device here

View Product

TurbiTech Suspended Solids & Turbidity

For measurement of solids in the Wastewater industry Partech Instruments offer the TurbiTechw² LA Suspended Solids Sensor for use in aeration systems monitoring suspended solids. This is also known as mixed liquor suspended solids or activated sludge where solids are typically in the range of 1,500 to 3,500 mg/l.

The sensor can also measure Returned Activated Sludge (RAS), Surplus Activated Sludge (SAS) and suspended solids or turbidity.  The fully automatic self cleaning system ensures that manual intervention on a routine basis is not required.

The large optical surface and sample volume combine to ensure that the sensor is providing information that is reliable and representative of the solids present in the process. Deposits of fats and grease on the sensing area do not prevent the sensor from measuring unlike sensors with small optical surfaces. In addition, the sensor incorporates a self cleaning mechanism that ensures the optical surfaces are kept clean at all times, the cleaning system is designed to avoid problems with ragging and does not smear the optical system.

View Product


We understand the importance of accuracy in your operations; therefore Quadbeam utilises the Four Beam ratio-metric self-compensating process. This allows you to measure only solids in the liquid, not what is stuck to the surface of the sensor. A range of sensors in available to best measure the level of solids you require, allowing you to achieve greater accuracy, and therefore increased control and efficiency.

Unlike other sensors, Quadbeam sensors will not encounter leaks with a rapid change in temperature during CIP cycles. Quadbeam Hygienic Sensors are 3A Sanitary Standards Accredited and can be used for both direct in-line process control in hygienic processes or for constantly monitoring waste or the non-hygienic line. Temperature resistance of standard range suits standard CIP temperatures. High Temperature resistant Sensors available for temperatures up to 105°C.

Quadbeam sensors have an easy user interface with 9 point lineariser to ensure simple set up and excellent accuracy. They can be calibrated to suit the product being monitored in your plant to ensure the most relevant data for your operations.

The purpose of the Four beam Alternating Light Principle design is to improve the measurement reliability of optical suspended solids and turbidity instruments . Sensors that use the Four beam technology compensate for most sources of measurement error such as contamination or dirt on sensor surface and ageing electronics. 

The alternating light principle of suspended solids measurement has been known for many years and we make no claim to its originality. However we have made major improvements to both its performance and reliability.

View 4-Beam Technology Here

View calibration setup Here

View Product