刘辉,秦敬玉,周超,贾然,张洋,孙学武,谷廷坤.开放环境中微小电阻测量回路伴随电势特性[J].电测与仪表,2023,60(4):139-143. Liu Hui,Qin Jingyu,Zhou Chao,Jia Ran,Zhang Yang,Sun Xuewu,Gu Tingkun.The characteristic of adjoint electrodynamic potentials of micro resistance measuring circuit in open environment[J].Electrical Measurement & Instrumentation,2023,60(4):139-143.
开放环境中微小电阻测量回路伴随电势特性
The characteristic of adjoint electrodynamic potentials of micro resistance measuring circuit in open environment
Different from the clean vacuum environment, in the open environment the junction of the resistance measuring circuit absorbs oxidizing gas, acid gas, water molecules, dust and other substances. It is found that the thermoelectric and chemical electrodynamic potentials of the measuring circuit have different behaviors with the time. The absolute value of the chemical potential has a non-monotonic decay with time. The chemical electrodynamic potential is formed within two metal interfaces on the metal knots by adsorbing water molecules and other chemicals. The chemical electrodynamic potential is dominant at the beginning of the test, and the absolute value is about 0.4 ~ 1.0 μ V, which decays to a very small value after a period of time. At this time, the adjoint electrodynamic potentials of the circuit is mainly thermoelectric potential, and the absolute value is about 0.1 ~ 0.2 μ V. The time of chemical electrodynamic potential decay to stable value may be greatly affected by environmental humidity, and the typical time is about 2000-3000 seconds. The research results are valuable for the design of precision resistance measurement and the designation of test system.
