On 19 to 29 June 2023, the following online COOMET training courses were held:

1. Calibration of gauge blocks (19-20 June 2023);

2. Calibration of calipers, micrometers and dial indicators (26-28 June 2023);

3. Uncertainty evaluation in length metrology with the method of Monte Carlo
   (29 June 2023).

where specialists of Armenia, Belarus, Kazakhstan and Uzbekistan took part.

The lead specialists of the NIM of China performed as the speakers during the courses: Mr. Xudong ZHANG, Mr Mingzhe LUO, Mr Yao HUANG.

In addition to the lecture materials, describing requirements to calibrations, the participants were shown videos demonstrating the process of calibration of gauge blocks, calipers, micrometers and dial indicators. Discussion took place with answers to the participants' questions.

The knowledge gained will allow the specialists of NMIs of COOMET member countries to organize the calibration of the above instruments in their metrological institutions, and to publish CMCs related to calibration services in the KCDB.