Calibration of Diameter Standards

Project Description

The project consists of a Key Comparison on the measurement of diameter gauges, and comes after the CCL Key comparison (CCL-K4.2015) now running. Due to the number of participants, the comparison is scheduled in two parallel groups. The circulating gauges are two rings (5 mm and 80 mm nominal diameter) and two plugs (5 mm and 100 mm nominal diameter) made of steel (AISI440C) and a ceramic ball (alumina, 20 mm nominal diameter). The measurands are the diameter and roundness at the equator of the ball, the diameter at the marked measurement direction and mid height of the cylinders, the straightness of the cylinders; the roundness at three sections of the ring 80 mm and of the plug 100 mm diameter. The circulating artefacts are newly purchased hence their history is unknown.

The comparison will be linked to CCL-K4.2015 through the linking labs CEM, INRIM and METAS. These three labs agree to participate in both groups for linking the two loops.

Final Report 2021-10-31

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

Progress Report 2019-07-01

Two rings (5 mm and 80 mm nominal diameter) and two plugs (5 mm and 100 mm nominal diameter) made of steel (AISI440C) and a ceramic ball (alumina, 20 mm nominal diameter) were circulated in each group. Both circulations were completed by 2018; due to customs issues there was a delay in the circulation of the group 2. 
The measurands are the diameter and roundness at the equator of the ball, the diameter at the marked measurement direction and mid height of the cylinders, the straightness of the cylinders; the roundness at three sections of the ring 80 mm and of the plug 100 mm diameter.
The Draft A of the group 1 was distributed by partners in January 2019, whereas the Draft A of the group 2 is expected to be circulated by partners in July 2019.