非自动衡器测量不确定度评估及其在符合性判定中的应用

以OIML R76国际建议中非自动衡器的称量试验为例,列举了2种容易对非自动衡器称量性能做出误判的情形。结合电子天平称量试验的3个案例,分析了修正误差与最大允许误差限较为接近时,直接采用“简单判定原则”作出符合性判定的误判风险,通过对线性载荷误差测量不确定度评估,分别对3个案例给出了95.45%、80.6%和18.1%的符合性概率。实验结果表明,在非自动衡器测量过程中,线性测量载荷误差满足最大允许误差限要求的非自动衡器,仍然可能存在不符合合格判定要求的风险,在法制计量中非自动衡器测量不确定度评估是降低产生误判结果的有效方法。

Measurement Uncertainty Evaluation of Non-Automatic Weighing Instrument and its Application in Conformity Assessment

On determining the weighing performance of a non-automatic weighing instrument( NAWI) from a weighing test result,there are 2 kinds of misjudgment risks if simple acceptance rule is applied when the measurement result is close to the maximum permissible error. Taking the test results of 3 electronic balances of a same type as an example,the measurement uncertainty for the corrected indication error is evaluated,whose influences on the conformity assessment is analyzed. The three kinds of conformance probabilities were 95. 45%,80. 6% and 18. 1%,respectively.The experimental results show that in the measurement process of NAWI,the NAWI whose linear measurement load error meets the maximum permissible error limit may still have the risk of failing to meet the requirements of conformity assessment. In legal metrology,the evaluation of measurement uncertainty of NAWI is an effective method to reduce misjudgment results.