DLO-M2 Liquid Density and Concentration Sensor

The sensor measures the density of liquids during the process itself – no need to go to the laboratory. Thanks to a sub-millimeter measuring channel, the liquid's properties and quality can be precisely monitored even in confined spaces.

The DLO-M2 sensor measures the density of liquids in a microelectromechanical system (MEMS system). Within the MEMS system, the liquid is directed to an omega-shaped microchannel, the so-called omega chip. This tiny silicon tube – it is hardly thicker than a hair – is set into oscillation for the measurement. The density of the medium can be derived from the natural frequency of this oscillation: the denser the medium, the lower the oscillation.

Thanks to the measurement in the MEMS system, the sensor is only 30 x 80 x 15 mm in size and can be accommodated even in tight spaces. The high-precision measurement results are immediately available, allowing continuous measurement during the process. The density of liquids depends on their temperature. To compensate for this effect, an integrated platinum resistor detects the temperature of the liquid.

The density sensor sends the measured data to the readout system via the data line in Modbus RTU transmission mode.

Measurement Features

  • Inline measurement directly in the process
  • Instantaneous readings
  • Quick change of media possible
  • Maximum measurement deviation: ±0.5 kg/m3
  • Repeatability: ±0.25 kg/m3
  • Modbus RTU


  • Determination of the mass of liquids: If the density is measured in addition to volumetric flow measurement in orifices, turbines or displacement devices, the mass can be calculated from it.
  • Monitoring and control of the quality of fuel mixtures such as E10 or biodiesel.
  • DLO-M2-EX (for hazardous areas): As a supplement to volumetric measurement during aircraft refueling & monitoring of the delivered and received density of the fuel in tank trucks.