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The relation between the accuracy of measurements of the radiochemical purity of a radiopharmaceutical sample by scanning the bands of a thin-layer chromatograph and the scanning parameters is demonstrated. The components of the measurement error are determined. The results of work to produce a metrological and apparatus backup for this method, in the form of the Gammaskan-01A scanning instrument, are presented.

A digital coincidence method is described in which the amplitude is digitized and the time of each pulse from the ionizing radiation detectors is recorded. The features of the processing of the digital amplitude-time measurement data are described in detail. It is shown that the digital coincidence method has a time resolution defined solely by the resolving power of the detectors.

A detailed discussion is presented on the main points of the Convention on the mutual recognition of national standards, calibration certificates, and measurements presented by national metrological institutes, and a survey is given of international collaboration to carry this out. Regional metrological organizations are important, and a survey is presented on work done in COOMET. Brief descriptions are given of ways in which the Convention may develop in the near future. The positive points from the implementation of the Convention are formulated from the author's experience and from research by other experts.

Self-calibrated resistance thermometers to be used as standards have been investigated. The heat exchange of the sensor coil with liquid helium per unit coil surface area at 0.3 K is 12 times better than that of a conventional gas-filled thermometer. The exchange is due to Kapitza surface thermal resistance. The λ point in liquid helium filling of the thermometer is reproducible to within 0.1 mK.

In 2003, the transition period came to an end for the mutual recognition of national standards, calibration certificates, and measurements issued by national metrological institutions. The paper considers the results from international collaboration attained in that period, which were discussed at the 11th meeting of the Joint Committee of Regional Metrological Organizations and the International Bureau of Weights and Measures.

We describe standard resistance thermometers made of a rhodium-iron alloy designed for operation in the temperature range 0.02-2 K. The sensitive element of the thermometer is filled with liquid helium-4 or helium3, which improves the heat exchange by several orders of magnitude. This makes it possible to significantly increase the measuring current and to use conventional technology for precise measurement of resistance.