Solid density comparison

Project Description

After the completion of the solid density key comparison CCM.D-K1, it is planned to perform a similar comparison that can be linked to CCM.D-K1. Thus, in the EURAMET comparison a 1 kg silicon sphere, 94 mm in diameter, should be measured in volume and density by the participating laboratories. Additionally, it is planned to measure two smaller spheres, 58 mm and 30 mm in diameter, to check a wider mass and volume range of the apparatuses and to support the CMC entries of the laboratories. The small spheres can be linked to the 1 kg sphere by pressure-of-flotation comparisons at PTB.

16 laboratories agreed to take part in the comparison. Further participants are invited to join. Due to the large number of participants the comparison will be organized in two petals. Therefore, six spheres are necessary. The NPL made available a 1 kg sphere and the BEV offered a 58 mm sphere that will be available in March 2008. The PTB accepted to pilot the comparison.
The comparison is planned to be a key comparison according to the MRA.

Final Report 2020-01-30

The comparison has been completed and results are available in the KCDB.

Progress Reports 2019-04-05

First version of Report Draft B was sent to EURAMET TC-M in April 2019.
Declarations about the impact of the comparison on their CMCs were received from participants with CMC entries.

Progress Report 2018-01-30

First version of Report Draft A was sent to the participants in January 2016. Some comments were received and the report has to be improved.

Progress Report 2017-05-17
First version of Report Draft A was sent to the participants in January 2016. Some comments were received and the report has to be improved.

Progress Report 2015-04-30

The measurements were completed and all results were sent to the pilot laboratory. Some participants were informed about "anomalies". Draft A of the report is in progress.

Progress Report 2011-03-10

In this key comparison, the measurements of density and volume of silicon spheres at 20°C and 101325 Pa are compared. The comparison is performed in two petals with three spheres in each petal. The samples of petal 1 are spheres with a mass of 1001 g, 200 g and 30 g. In the second petal, the spheres have a mass of 984 g, 239 g and 30 g. The two petals are linked by measurements at CEM, METAS, NMIJ and PTB. The link to the 1 kg silicon sphere of the CCM key comparison CCM.D-K1 is realized by the institutes CEM, INRIM, METAS, NMIJ and PTB. The smaller spheres are linked to the 1 kg spheres by pressure-of-flotation measurements at PTB and NMIJ. This method can also be used to link the two petals.

Up to now, 12 laboratories measured in Petal 1 and eight in Petal 2. Only a re-check measurement of Petal 1 at NMIJ and mass measurements at PTB are missing.

Progress Report 2010-02-23

In this key comparison, the measurements of density and volume of silicon spheres at 20 °C and 101325 Pa will be compared. The comparison is performed in two petals with three spheres in each petal. The samples of petal 1 are spheres with a mass of 1001 g, 200 g and 30 g. In the second petal, the spheres have a mass of 984 g, 239 g and 30 g. The two petals are linked by measurements at CEM, Metas and PTB. The link to the 1 kg silicon sphere of the CCM key comparison CCM.D-K1 is realized by the institutes CEM, INRIM, Metas, NMIJ and PTB. The smaller spheres are linked to the 1 kg spheres by pressure-of-flotation measurements at PTB. This method can also be used to link the two petals.
Up to now, nine laboratories measured in Petal 1 and six in Petal 2. The last measurements are scheduled for June 2010.
In principle a late entry of a participant is possible provided that the time schedule is not extended more than necessary.

Progress Report 2009-03-02

In this key comparison, the measurements of density and volume of silicon spheres at 20 °C and 101325 Pa will be compared. The comparison is performed in two petals with three spheres in each petal. The samples of petal 1 are spheres with a mass of 1001 g, 200 g and 30 g. In the second petal, the spheres have a mass of 984 g, 239 g and 30 g. The two petals are linked by measurements at CEM, Metas and PTB. The link to the 1 kg silicon sphere of the CCM key comparison CCM.D-K1 is realized by the institutes CEM, INRIM, Metas, NMIJ and PTB. The smaller spheres are linked to the 1 kg spheres by pressure-of-flotation measurements at PTB. This method can also be used to link the two petals.
Up to now, five laboratories measured in Petal 1 and four in Petal 2. The last measurements are scheduled for March 2010.
In principle a late entry of a participant is possible provided that the time schedule is not extended more than necessary.