Measuring instruments

The legal metrology covers measuring instruments (MI), the measurement results of which are used in calculations for consumed energy resources, in the fields of information protection, security, environmental protection, etc. Most modern MIs use microcontrollers or are controlled by computers. The software (SW) of such MIs provides an opportunity not only to automate the processes of measurement and calculation of results but also to ensure long-term storage and data transfer. The manufacturer is responsible for investigating and assessing all possible risks related to the MI SW.

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.

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.