Kontrolltasandite

Kontrolltasandite, translated as control sands, is a term used in Estonian geotechnical and construction practice to denote standardized sand samples employed as reference materials for quality control and calibration of laboratory tests on granular materials. They provide a consistent material against which laboratory procedures, such as sieve analysis, grain-size distribution, moisture content determination, and density measurements, can be checked to ensure accuracy and comparability of results between laboratories.

Kontrolltasandite are produced to defined specifications, including target grain-size distribution, mineral composition, moisture content, and bulk density. Each batch is accompanied by a certificate that records the measured properties and the associated uncertainty. The aim is to cover a representative range of sands used in construction work, from fine to coarse grades, so that testing equipment and methods can be routinely validated.

In practice, laboratories use kontrolltasandite for calibration, method verification, and participation in inter-laboratory comparisons. They help verify the performance of sieve shakers and balances, assess repeatability of tests, and serve as a stable reference when adopting new test procedures or equipment. By providing a known material standard, they contribute to quality assurance and regulatory compliance in geotechnical testing.

Standards and procurement practices vary by country, but many laboratories obtain kontrolltasandite from certified providers that supply reference materials with documented specifications and traceable certificates. Some jurisdictions also maintain national or regional sets of reference sands to support proficiency testing and accreditation programs.

See also: Certified reference material, Reference material, Proficiency testing, Sieve analysis.