Valmet Dry Solids Measurement - Valmet DS

Valmet Dry Solids Measurement (Valmet DS) for dried wastewater sludge (dry cake), is installed after the dewatering machine at municipal wastewater treatment plants. Accurate measurement of biosolids provides significant savings in polymer dosage, energy, and dewatered solids transportation.

A new solution for dry cake measurement

Valmet Dry Solids Measurement (Valmet DS) utilizes microwave technology, requiring no special certification or safety procedures, to make a stable and
accurate solids measurement for dewatering control in waste water treatment. Valmet DS extracts a continuous sample from the falling cake flow after a centrifuge or screw press and measures the solid content before returning the sample back to the process.

Continuous measurements bring cost savings for wastewater management

Feedback control using the accurate dry solids measurement provided by Valmet DS can fully optimize polymer dosage and provide energy savings through better torque control of the centrifuge. Maximizing drying efficiency to a target dry cake solids content can provide additional savings with reduced transportation costs and improved power boiler combustion.

  • Reliable screw based sampling
  • Cake solids range up to 35 %
  • Built-in calibration routine
  • Industrial Internet remote access

In addition to full remote access of Valmet DS functions, measurement data, alarms and diagnostics via the Industrial Internet, the Valmet DS Ethernet connection can be used for local control with a laptop or tablet computer during commissioning.


Valmet DS is typically located in the downfall section of the dry cake. A sample retrieval screw feeds a return screw which compresses and pushes the sample
through the microwave sensor chamber before being returned to the process.

The Valmet DS measurement is based on multivariable microwave resonance, compensated for varations in material temperature and calibrated during commissioning with samples taken from the screw and oven dried.



Click here for more Valmet Dry Solids Measurement technical data





Solids Measurement For Better Wastewater Control – Click here to download Valmet Wastewater Guide


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Valmet wastewater treatment process

Sensor material Ceramics / Body Aisi 317L
Measuring range Up to 35 % solids
Material measured

Municipal dried wastewater (sewage) cake

Temperature range +0...65 °C
Repeatability 0.01 %
Resolution 0.001 %
Mill system interface 4...20 mA, Ethernet

24 VDC (measuring electronics)
3 phase AC (sample screws) *

IP-classification IP65

Customer success stories

Valmet goes underground to help treat wastewater

Valmet goes underground to help treat wastewater

The Kakolanmäki wastewater treatment plant has been operating in the southern Finnish city of Turku since the beginning of 2009. Since the plant is built underground it has a more constant and higher temperature than surface facilities, a distinct advantage for treatment conditions.

Valmet wastewater solutions save energy and chemicals

Valmet wastewater solutions save energy and chemicals

Tampere Water recently installed several Valmet total solids measurement devices and a sludge dewatering control package at its Viinikanlahti wastewater treatment plant in Tampere, Finland.

Increased energy and environmental efficiency at Tampere Water

Valmet Dry Solids Measurement (Valmet DS) will help Tampere Water to save on running costs and chemical usage, and to increase capacity.

   Johanna Luomanen, Tampere Water and Heli Karaila, Valmet at Viinikanlahti waste water treatment plant

Article (in Finnish) published in Finnish trade magazine Tekniikka & Talous, Sep 2, 2016. 

Viinikanlahden puhdistamon läpi virtaa noin 80 prosenttia Tampereen alueen jätevesistä. Mittaus ohjaa puhdistusprosessia hyvin tarkkaan. "Kun aikaisemmin otimme näytteitä, lähetimme laboratorioon ja odotimme pari päivää, saamme nyt tarvittavan tiedon välittömästi", käyttöinsinööri Johanna Luomanen kertoo.