Development And Testing For Standards Mutual Inductance Coil Used To Joule Balance

In recent years, with the progress of social development, people have becomeincreasingly high demand for instruments and the precision instruments can enhance the levelof the manufacturing industry. In the field of metrology, people gradually feel it cannot meetthe needs of modern society that use of physical benchmarks to define and reproduce theseven basic units. Many countries including China have begun to explore the use of quantummethods to define and reproduce the International System of Units. Metrologists have maderemarkable achievements in the last half century. But the unit of mass, kilogram, is stilldefined as a material artifact standard. Currently, metrologists have explored a variety ofmethods. The Watt balance is a way that mature and likely to succeed. Its basic idea is todefine kg basis on electromagnetic force that have been quantization and gravity. This paperbriefly compare those programs, focuses on the joule balance of China. Chinese Jouleprogram by precisely measuring DC mutual gradient to export quality. The balance requiresaccurate measure mutual inductance in zero mutual inductance region. We all know itsdifficult to measure small mutual accurate. It can be a good solution what superimpose on ahigh stability mutual bias in equilibrium position to this problem.The main content of this thesis is to study the mutual coupling multi-coil system. First,by analyzing the impact of the reason mutual stability. Then assess the extent of the impact ofthese factors by comparing experiments. Finally find a solution to improve mutual stabilityand developed a very good stability coil system.The factors may affecting stability include different temperatures, different frequencies,different currents, different external electromagnetic environment and so on. Experimentaldata demonstrate equipotential shield can greatly improve the stability of topics of mutualinductance coil. Temperature is a big influence on the mutual inductance values, reached4.89×10-5H/℃. So mutual inductance coil needs to work under constant temperature. Bycontrolling the current and temperature to ensure the stability of the mutual inductance values.There is no direct impact on the distribution of mutual capacitance value, but will affect thedistribution of mutual capacitance measurement accuracy when measuring mutual inductance.Using12Hz and120Hz two frequency the measurement result of mutual inductance’sdeviations reach10-4.This paper studied the mutual inductance coil can provide a variety of mutual value andshort-term stability are reached10-7,meet the requirements of Joule balance.