742A-1及742A-10k型传递标准电阻值测量结果不确定度的评定

Evaluation of the uncertainty of the measurement results of 742A-1 and 742A-10k type transfer standard resistance values

742A标准电阻是供精密电阻校准使用的高准确度工作标准。随标准电阻提供校准修正数据表,表中的修正值以0.5℃的温度间隔给出,其优异的温度稳定性使之可以工作在18~28℃的温度范围之内。742A小巧坚固、使用方便,大大减小因温度和机械振动而导致的电阻变化。根据QJ55宽量程直流比较仪式电桥的测量原理,采用直接比较法,用一等标准电阻器和QJ55型直流电流比较仪式电桥,对742A标准电阻进行检测,对测量结果的不确定度评定,分析测量过程中不确定度的来源,并量化分析,得到合成标准不确定度和扩展不确定度。

The 742 Astandard resistor is a high accuracy standard for calibration of precision resistance.With the standard resistor to provide a calibration correction data table,the correction value in the temperature interval of 0.5℃is given,742 Acan be used in the air,do not need to use a very troublesome oil tank.The excellent temperature stability can be made at the temperature range of18℃to 28℃.742 Acompact,easy to use.The resistance change caused by temperature and mechanical vibration is greatly reduced.According to the measurement principle of QJ55 wide range direct current bridge,the direct comparison method is used to detect the 742 Astandard resistance,and the uncertainty of measurement results is analyzed.The uncertainty and the expanded uncertainty of the standard are obtained.