Four Beam Turbidity & Suspended Solids Technology

Quadbeam | Four Beam Turbidity & Suspended Solids Technology

At Quadbeam Technologies, we understand that as a plant manager or engineer you’re concerned about improving efficiency, reducing costs, and delivering a better quality product to your customers. That’s where we come into play: Quadbeam Technologies designs and manufactures the world’s finest suspended solids and turbidity meters to ensure that your operations perform at their best to keep you ahead in your industry.


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 the 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.



Most competing systems use a single beam design which rely on mechanical cleaners to eliminate variations due to dirt accumulation, but do not compensate for ageing or voltage variations.

As shown on the graph below, single beam sensors drift a significant amount, whereas the four beam sensors have virtually no drift providing unrivalled accuracy and reliability when compared with competitive systems.



The Quadbeam Alternating light principle compensates for variations in both light intensity and detector sensitivity using ratiometric signalling. It features two light sources which are switched on and off alternately and two detectors.

Quadbeam | Four Beam Turbidity & Suspended Solids Sensor


Watch our Explanatory Video here:

Explanatory note comparing single beam with multi-beam 

Principle of four beam operation