PARIO

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PARIO

Automated Soil Particle Size Analysis

A revolutionary new method for soil particle analysis. Automated, simple, and fast—with much less human error than traditional methods.

Automated Soil Particle Size Analysis
Lower measurement duration of 2.5h
Estimated error: an incredible ± 0.5%

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Overview / Features

New technology—new possibilities

Soil particle size analysis traditionally had only two options—the extremely archaic option or the extremely expensive option. The hydrometer (or pipette) method is a painstaking, manual process that’s prone to error. The ultra-expensive laser method has accuracy issues because flat soil particles like clay can confound the measurement. Both methods can lead to hours of wasted time. Now there’s a new way. Introducing PARIO.

Complete curves made easy

PARIO uses automation to shrink the time and effort needed for soil particle size analysis. It calculates the particle size distribution by Stokes’ law, with a range spanning from 63 μm to 2 μm, finally making it easy to obtain a complete particle size distribution curve, instead of just a few measurements at discrete time points.

It allows for unattended, automated operation (with the exception of opening the valve after completion). Just set it up and come back later to a finished measurement with all the data you need.

New method reduces error—and effort

PARIO adopts the same sample prep your lab already uses, so it fits perfectly into your existing workflow. It reduces errors by replacing and automating the lengthy “hydrometer” portion of the process using the new, more accurate “Extended Integral Suspension Pressure Method” (ISP+). This method 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 calculation errors. This results in an overall error rate of an incredible 0.5%—lower than any conventional particle size analysis method.

Stokes’ law method

The PARIO measuring method is based on Stokes’ law. 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.

Spend more time on what matters

To save you even more time, PARIO soil texture analyzer comes with an easy-to-use, all-in-one software solution for automated data inquiry, visualization, evaluation and export. Plus, PARIO, as part of the LABROS system, can be combined with the HYPROP, KSAT, or WP4C to completely characterize the physical and hydraulic properties in soil.

All of this serves one goal—to reduce the operating time you spend for particle size analysis, while at the same time improving accuracy. Skip hours of tedious manual measurements and focus on your research.

Feature summary

Get complete particle size distribution curves
Calculation of particle size distribution by Stokes’s law
Autonomous operation after measurement start (with the exception of opening the valve at measurement end)
Lower measurement duration of 2.5h
Estimated error: an incredible ± 0.5%
Quasi-continuous 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 in the calculation of particle size distribution
Direct measurement of clay content
PARIO Plus improvements mean external data errors are less problematic

Specifications: TECHNICAL SPECIFICATIONS

Measurement Specifications

Typical Duration of Measurement

PARIO Classic: 8 h

PARIO Plus: 3 h

Particle Size

Range: 2 – 63 μm

Approximate Error in Mass Fraction Detection

PARIO Classic: ±3 %

PARIO Plus: ±1 %

Estimation of Clay Content

Derived from integrated particle mass in effluent

Estimation of Sand Fraction

Sand fraction estimated by sieve data

Pressure Measurement

Accuracy: ±1.0 Pa

Resolution: ±0.1 Pa

Measurement Interval

10 s

Typical Particle Mass

25−50 g per 1-L suspension

Communication Specifications

Power Requirements

USB 5 V/100 mA

Computer Compatibility

Microsoft Windows 10

Physical Specifications

Cable Type

USB 2.0; 500 mA for receiving port

Glass Cylinder

Height: 450.0 mm (17.7 in)

Diameter: Inner: 59.0 mm (2.3 in)
Outer: 67.5 mm (2.7 in)

Volume: 1,000 cm³ (61.0 in³)

Material: Borosilicate glass 3.3

PARIO Device

Height: 293.0 mm (9.1 in)

Diameter: 80.0 mm (3.2 in)

Material: Polyoxymethylene plastic (POM) and stainless steel

Volume of Suspension

1000 mL

Maximum Tolerable Temperature Change During Measurement

±1.50 °C

Required External Measurement

PARIO Classic: Content of organic matter (if OC is destroyed)
Sand fractions (from wet sieving)
Mass of dispersion salt in total suspension volume

PARIO Plus: Mass of dry matter in discharged subsample
Sand fractions (from wet sieving)
Mass of dispersion salt in total suspension volume

Operating Temperature Range

Minimum: 15 °C

Typical: 20 °C

Maximum: 35 °C

Other

Other Compatible Software

PARIO result files are compatible with the interface of LASTRADA laboratory software (Sieving and Sedimentation module)

Product Awards

Winner of the Red Dot Design Award

Compliance

EM ISO/IEC 17050:2010 (CE Mark)

GSA

View GSA details

Support / FAQ

PARIO User Manual

Manual

PDF, 0.0047MB

Example PARIO Measurement File (Silt Loam)

Instructions

URL, 0.398MB

Research Article: The Improved Integral Suspension Pressure Method (ISP+) for Precise Particle Size Analysis of Soil and Sedimentary Materials

Instructions

URL, 0MB

PARIO Control Software

Software

EXE, 132MB

Video: PARIO Plus-How To Make A Measurement

Instructions

URL

PARIO FAQs

The PARIO device is not recognized by the software.: Check to ensure the device is shown in the device manager. If it is listed under “other devices,” please try to update the driver. If it is listed under “USB controller,” please contact METER support.

Is there an instruction video for PARIO?

Do the PARIOs have to be sent to METER/Germany for calibration on a regular basis (recommended in the PARIO manual to send the devices for calibration verification every 2 years)?: The functionality of the PARIOs can be tested by running a measurement on air and in distilled water. A complete check of the calibration and a recalibration can only be made by sending the device to METER. It is not mandatory to send it in every two years if it still works correctly.

Do I have to consider the mass of dispersant in the calculation of the mass of particles?: It depends. When the dry soil weight is determined with a pretest sample, mass of dispersant does not have to be considered in evaluation. Furthermore, the software automatically corrects the pressure values, considering the different density.

Similarly, if the PARIO sample is wet-sieved after the PARIO measurement, the mass of dispersant does not have to be considered by determining the dry soil weights of the sieve residues as it should be washed out completely.

If, on the other hand, the dry soil weight is determined after PARIO measurement, the mass of dispersant has to be subtracted from the total dry soil mass.

What happens if I shake and measure the same sample multiple times?: Clay conglomerates dissolve amongst others because of mechanical abrasion of the particles, which consequently causes a slight increase in the clay fraction.

What is the upper limit of mass of material that can be used?: Software limit: 100 g

The more material you have in the cylinder, the more accurate the measurement is as you have an increasingly recognizable change in pressure. On the other hand, a disadvantage regarding Stokes’ law explains that more particles in the cylinder can influence each other during the sedimentation process. The amount of particle mass is also limited through the limited measuring range of the pressure sensor.

How do I fill the sedimentation cylinder correctly?: The surface of the suspension in the sedimentation cylinder forms a curved meniscus. The meniscus contacts the liter mark at the deepest point. Remove air bubbles by lightly knocking on the glass. Additionally, use a dropping pipette for precise filling of the cylinder.

What condition should the initial material have?: The initial material should be an air dry soil sample which is sieved to 2 mm.

What happens if the organic matter is not destroyed?: Organic matter works as a cementing substance and can lead to aggregation of the primary particles. This falsifies the sedimentation of the single particles.

What are the possible reasons for an increasing pressure curve at the beginning of the measurement?

Air bubbles in the suspension, which arise during shaking and rise up during measurement
Water drops which run down the border of the cylinder during measurement
Foam, arising from shaking and dissolving during measurement

What is the minimum pressure change necessary for a valid measurement?: A minimum pressure change of 10 Pa during the whole measurement time is valid.

Often the measured clay content rises with the number of repeat measurements of the same sample.: This effect may be a consequence of the shaking process before starting the measurement. The more often you shake the suspension, the more the dispersion increases, and the larger particles rub together and decrease in size.

The "Value [%]" column should specifiy the fraction of grains retained on the respective sieve. But what is the basis of the calculation?: The basis is the total dry soil weight of the total sample you weighed into the PARIO cylinder, including sand, silt and clay.

Sometimes the software does not recognize the start of the measurement when putting the sensor into the suspension.: This may happen if the tilt angle (approx. 45 °) is not big enough, or if the tilting is too tentative. Please refer to the following link for a quick video on the correct tilting of the sensor unit.

How is it calibrated? Is it calibrated annually? How can we assure that the pressure recording is correct?

PARIO is calibrated with a two-point pressure calibration using an accurate reference pressure sensor. A multi-stage temperature calibration (range 10 °C–30 °C, 5 steps) is done in a climate chamber.
PARIO is calibrated once after manufacturing, not annually.
You can check the performance of the device by taking a measurement on air. The pressure should be about 0 Pa (± 5 Pa). In addition, you can measure in clear distilled water. The pressure should be at about 1800 Pa (± 5 Pa).

What should I do if soil particles stick on the cap or in the glass after mixing?: The particles that stick to the glass cylinder after shaking are the coarse sand particles (finer particles are carried with the water). The coarse sand particles are not part of the sedimentation analysis. The proportion of the sand fraction has to be determined by wet sieving of the material separately. This problem is common with a sedimentation experiment, including those conducted using a hydrometer or pipette method.

Resources / Publications