Calibration

The purpose of the study is the development of calibration methodology of automated verticality monitoring system of radio communication masts and towers using geodetic measurements in order to obtain corrections in inclinometer measurements relative to the construction’s vertical axis. There are two different methods used for tower verticality determination: using Global Navigation Satellite Systems (GNSS) observations; three-dimensional terrestrial geodetic measurements using total station or traditional geodetic measurements methods.

The specific of metrological support for different types of dosemeters are considered. Gamma-ray sensors are commonly used for measuring radiation doses as also the fluid levels in the industry. Typically, the 60Co or 137Cs isotopes as the radiation source are applied. For instance, in the USA, such detectors are beginning to be used as part of the Container Security Initiative [1]. Problems of their metrological assurance are becoming more general.

A method has been developed for the adjustment of the results of measurements of length during calibration of a field comparator for verification (calibration) of distance meters and distance metric parts of total stations. The method of processing the results of comparisons of distance meters to the field comparator using the least squares method (LSM) was also developed on its basis. The additive biases of length measurements by each distance meter are evaluated according to the LSM, as well as the biases that are entered to the results of length measurements by each reflector.

The article focuses on the main problems of metrological confirmation of measuring instruments in accordance with international requirements and considers possible directions of their solution. One of the main tasks of metrology is assurance of the uniformity of measurements, that is, the state of measurements, in which their results are expressed in the legal units, and the characteristics of errors or uncertainty of measurements are known with a certain probability and do not exceed  the established limits.

The article deals with the development of the reference means of support and metrological insurance required for  metrological  verification  and  calibration  of  beta  and  gamma  radiation  dosimeters.  The  latter  are  extremely  necessary  for dosimetric measurements of radiation characteristics in the field of radiation safety, radiation diagnosis and therapy.

Digital  frequency  synthesizers  are  widely  used  in  various  fields  of  technology.  Their  main  advantages, compared  to  analog  devices,  are  the  accuracy  of  output  signal,  resistance  to  external  factors,  reliability  and  high  performance. Their structures include the digital storage device (accumulative adder) and a comparison scheme. Basing the latest the two-level digital frequency synthesizers are developed. They are the subset of digital frequency synthesizers, in which the output signals are two-levelled.

Ensuring the unity and metrological traceability of measurement results becomes the key component necessary to reach market confidence in the results of calibrations, tests or measurements. Important aspect of maintaining the ability of the laboratory to receive metrological traceability and reliable measurement results is to determine the maximum permissible period between two calibrations of the standards and measuring instruments that provides the acceptable accuracy of measurements during their operation.