referentiemasses

Referentiemassen, in metrology, are reference masses used to calibrate and verify mass-measuring instruments such as analytical balances, precision scales, and industrial weighers. They provide a stable, known mass that allows instruments to produce accurate readings and to demonstrate traceability to the International System of Units (SI).

Construction and characteristics

Referentiemassen are typically made from corrosion-resistant metals such as stainless steel or high-density alloys. They are designed to minimize mass change due to surface contamination, humidity, and air currents. The masses are ground, polished, and stabilized to a tight tolerance, with protective housings or boxes to guard against damage. Common nominal sizes range from milligrams to several kilograms, with corresponding tolerance classes and calibration certificates.

Certification and traceability

Each referentiemassa has markings that indicate its nominal value, tolerance, material, and a certificate of calibration. They carry documentation that their mass is traceable to the SI kilogram through a defined calibration chain, often involving national metrology institutes and international standards set by bodies such as the International Organization for Legal Metrology (OIML) and ISO guidelines.

Use in calibration

During calibration, a balance or scale is adjusted so that its readings match the known masses of the referentiemassen. This process may involve a series of masses across the instrument’s operating range to verify linearity and accuracy. Regular use and periodic re-certification maintain confidence in mass measurements and ensure compliance with quality and regulatory requirements.

Relation to the kilogram

Since the redefinition of the kilogram in 2019, the SI unit is fixed to a fundamental constant, but physical reference masses remain essential for practical calibration and performance verification, preserving traceability to the SI unit in everyday laboratory and industrial settings.