# Mass standards and weights

The 26th General Conference on Weights and Measures (CGPM) has adopted a revision of the International System of Units (SI) on 16th November 2018, effective from 20th May 2019. As a result, all SI units refer to fixed values of seven constants of nature. In the new SI, the kilogram is derived from a fixed value of the Planck constant (in conjunction with fixed values of the frequency of the unperturbed ground state hyperfine transition frequency of the 133Cs atom and of the speed of light in vacuum). As a consequence, the standard uncertainty (k = 1) of the mass of the international prototype of the kilogram with respect to the Planck constant amounts to 0.010 mg. This uncertainty contribution needs to be taken into account in the dissemination of the mass unit after 20th May 2019.

#### Smallest uncertainties

Nominal value  Uncertainty
(2 uc)
Nominal value Uncertainty
(2 uc)
1 kg   0,030   mg
500 g   0,016   mg        2 kg           0,07     mg
200 g   0,008   mg        5 kg          0,17     mg
100 g   0,005   mg      10 kg          0,35     mg
50 g   0,0030 mg      20 kg           2,0       mg
20 g   0,0019 mg      50 kg           5          mg
10 g   0,0015 mg    100 kg    0,15            g
5 g   0,0011 mg    200 kg    0,20            g
2 g   0,0008 mg    500 kg    0,4              g
1 g   0,0007 mg  1000 kg    0,6              g
500 mg   0,0006 mg  2000 kg   1,1              g
200 mg   0,0006 mg  5000 kg    2,5              g
100 mg   0,0006 mg
50 mg   0,0005 mg
20 mg   0,0004 mg
10 mg   0,0004 mg
5 mg   0,0004 mg
2 mg   0,0004 mg
1 mg  0,0004 mg

# Average Fees for the Calibration of Weights in EURO

 KVONL of December 17, 1970 as last revised with effect from Feb 01,2019. Excepted are costs for transport, packing, customs duties, remittances from abroad. Costs for services are calculated based on the expected time and effort. The following average fees are valid only for the calibration of weights with the given measurement uncertainties. Nominal value Class E2*) U = δm/3 Class E1*) U = δm/3 more accurate than Class E1*) U = δm/5 Determination of mass volume mass volume mass 1 mg bis 500 mg, per pc. 132,- - 396,- - 528,- 1 mg bis 500 mg, 12 pc. 1408,- - 3168,- - 4048,- 1 g bis 1 kg, per pc. 220,- 264,- 220,- 440,- 484,- 1 g bis 1 kg, 13 pc. 1804,- 1980,- 1804,- 4312,- 3432,- 2 kg bis 10 kg, per pc. 220,- 440,- 220,- 792,- 484,- 20 kg bis 50 kg, per pc. 264,- 440,- 264,- 484,- 484,- 100 kg to 5000 kg, per pc. upon request (dependent on the expenditure and dimensions) preparatory and final work, per order 176,- per Calibration Certificate 176,-

A volume determination generally is not necessary for Class E2 and all classes for nominal values below 1 g. For Class E1 and more accurate calibrations, a volume determination will not be required if the volume is known with sufficient accuracy.
*) δm   corresponding the error of conventional mass in accordance to the International Recommendation OIML R 111.