Measurement standard of mass


The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15×10–34 when expressed in the unit J s, which is equal to kg m2 s–1, where the metre and the second are defined in terms of c and ∆νCs.


In the Estonian national mass measurement standard laboratory the scale is realised in the measuring range of 1 mg to 50 kg by using a set of 1 kg reference weights and precision comparators. 1 kg reference weights are calibrated in the German National Metrology Institute PTB.

See the approved list of national measurement standards.


Automatic comparator AX1006
Automatic comparator AX1006

For offering a calibration service automatic comparators AX107H, AX1006 and AX64004; precision scales UMT 5 and AX504 and reference weights are used.

Weights of classes from E2 to F1 with the expansion uncertainty from 2 μg to 15 mg are calibrated in accordance with OIML’s recommendation R111-1.



Teaduspargi 8, 12618 Tallinn

Phone: +372 5667 8866, +372 508 1129

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Riia 142, 50411 Tartu

Phone: +372 508 1384

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Sompa 1A, 41533 Jõhvi

Phone: +372 337 3060, +372 5912 6504

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Assay office

Teaduspargi 8, 12618 Tallinn

Phone: +372 508 1129

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