soil particle size analysis


  • PARIO soil particle size analysis from METER Group (formally UMS)
  • Calculation of particle size distribution by Stokes’ law
  • Autonomous operation after measurement start
  • Quasi-continous resolution of particle size distribution
  • No physical disturbance of suspension during measurement
  • Avoidance of manual reading errors
  • Avoidance of manual calculation errors
  • Temperature dependence automatically integrated calculation of particle size distribution

Conventional soil particle size analysis operation takes a lot of time and energy. Readings or samplings have to be done by hand, at regular intervals, and for up to 24 hours. Because the procedure is manual, it’s prone to errors—which can easily lead to wasted time and effort.

Our goal at METER is to give you the tools and services that allow you to get precise results and focus on your research. That’s why we developed a revolutionary new way to reduce the time and effort needed for soil particle size analysis.


particle size analysis, automated

PARIO calculates the particle size distribution by Stokes’ law, with the range of particle sizes spanning from 63 μm to 1 μm.

It allows for unattended, automated operation, with no interference by lab personnel. Just set it up and come back 6 hours later to a finished measurement with all the data you need.


measure more and worry less

PARIO reduces errors, because it does not require the insertion of a hydrometer or sampling of suspension volume with a pipette, which disturbs the sedimentation process. Being automatic, it also avoids manual reading or calculating errors. This results in an overall error rate of just 3%—lower than any conventional particle size analysis method.

PARIO automatically measures at an interval of 10 seconds and continuously records the change of suspension pressure as well as the temperature. This results in highly—accurate and continuous particle size distribution curves. The data are automatically evaluated by our new data processing algorithm called “Integral Suspension Pressure Method” (ISP).

The PARIO measuring method is based on the well-established hydrometer or pipette method. That means there is no need for soil-specific corrections with transfer functions as required for almost any other automated measurement method, such as laser diffraction or image analysis.


complete convenience

To save you even more time, PARIO comes with an easy-to-use, all-in-one software solution for automated data inquiry, visualization, evaluation and export.

All of this serves one goal—to reduce the operating time you spend for particle size analysis, while at the same time improving accuracy. So you can focus on your research, not operating machines.

The new PARIO soil texture analyzer. Reducing operation time to particle size.


scientific research
  • Durner and Iden (2021). The improved integral suspension pressure method (ISP+) for precise particle size analysis of soil and sedimentary materials. Soil & Tillage Research, 213, 105086.



feature specification
particle size range 63 μm to 1 μm (eff. hydrodynamic diameter)
mass fraction detection error ± 3 %
typical particle mass 25 to 40 g/L suspension
typical measurement duration 8 hours
measuring interval 10 seconds
operating temperature 15 °C to 35 °C
max. tolerable temperature change during measurement 3 °C
warranty 12 months

manual & docs

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