The analysis of requirements for metrological parameters of digital temperature meters and temperature difference meters for solar collectors’ investigations been done in the article. Under the regulations requirements a minimum temperature drop not exceed 1,5 K, and for the maximum relative error of temperature measurement not more ±2% it provide the absolute error of temperature drop measurement near ±0,030 K, and their measurement unit list significant digit 0,01 K.
This work presents a method of in-situ calibrating 3D magnetic sensors based on Hall devices that have linear field characteristics and are non-orthogonal, with known position of each Hall device in relation to the 3D sensor’s substrate. Formulas for calculation of Hall devices linear coefficients are obtained. The method’s efficiency is proved experimentally.