OLPAS Technology

All Olpas sensors are build using the unique OLPAS Technology... 

Animation showing Olpas sensor using pulse-echo measurements

Measuring the solids concentration in fluids

Olpas concentration measurements for suspensions are based on ultrasound pulse-echo measurements. A low power, intrinsically safe, ultrasound pulse is sent into the medium.


The backscattered echo is recorded by the transducer itself, allowing easy mounting of the transducers in any situation.

Olpas dataprocessor

Backscattering echoes are recorded and processed in the OLPAS dataprocessor. In less than 100 microseconds a measurement is performed and a reliable concentration measurement is obtained. Measurement output is instantaneous and compatible with most industry standard control systems.

Olpas TSS Dataprocessor - Electronics PCB
Olpas sensor can be mounted in a pipe any direction.


Olpas sensors can be mounted in any direction using any type of process connection due to their small size and stainless steel housing. The sensor is sensitive to all types of solid particles independent of density or size, from fine nanometer-sized particles in nanofluids up to millimeters. Organic or inorganic particles, polymers or slurries: the OLPAS analysis of ultrasound backscattering signals is inherently robust and reliable to determine the solids concentration.

Pool and inline measurements are both feasible with the majority of mounting solutions or process connections directly compatible with our sensors. The ultrasound signal is measured locally, allowing mounting of the sensor in small and large pipes without interference from surrounding materials.

True-TSS & True-MLSS

In wastewater treatment the real, true, values of the Total Suspended Solids (TSS), Mixed Liquor Suspended Solids (MLSS) or activated sludge concentration are key parameters for process control.

Due to the nature of the OLPAS technology using ultrasound backscattering, an intrinsic measurement of the solids concentration is obtained. The ultrasound pulse propagates in the fluid and the resulting backscattering echo is a representative fingerprint of the suspension concentration. 

Ultrasound backscattering is independent of flow conditions, temperature or colour of the medium.


Fouling resistance of the Olpas backscattering sensors is far superior to competing technologies.

Waste water with sludge - Ideal for Olpas sensors