Development of a certified reference material for the physical properties of the soil clay (loam)

Abstract

Introduction. The article presents results of developing a certified reference material for the physical properties of the soil clay (loam). The certified characteristics of the reference material are as follows: moisture content at the liquid limit via fall-cone test, moisture content at the plastic limit, soil particle density via pycnometer method.Materials and methods. The certified values of the physical properties of the soil clay (loam) were determined using the method of interlaboratory metrological experiment.Results. The bounds of absolute error of the certified values are as follows: 1.9 % for moisture content at the liquid limit via the fall-cone test, 1.5 % for moisture content at the plastic limit, 0.03 g/cm3 for soil particle density. The validity period of the certified reference material is 5 years.Discussion and conclusion. The developed reference material was registered in the State Register of type-approved reference materials as GSO 11038–2018. The reference material is aimed at: controlling the accuracy of the measurement results of certified characteristics; conducting interlaboratory comparisons; testing laboratories proficiency.