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酱卤肉制品中菌落总数测量结果不确定度评定 总被引:3,自引:0,他引:3
测量不确定度是对测量结果可疑程度的一种定理表述。为减小实验误差,提高检测准确度,根据GB/T4789.2-2008《食品卫生微生物学检验菌落总数测定》建立了散装酱卤肉制品中菌落总数测量不确定度数学模型,评定了由重复性测量的分散性引起的合成标准不确定度和扩展不确定度,并对测量结果进行了表述,为该检验方法的不确定度评定提供一个参考。 相似文献
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水分测定仪已广泛使用于各个领域的实验室,是测定含水量快捷方便,是各类物质重要的质量指标之一。具体通过对IR35型号的水分测定仪进行不确定度的评定,用35g标准砝码的不确定度、数字显示水分测定仪测量重复性、数字显示水分测定仪天平分辨力、数字显示水分测定仪四角误差,这四项进行合成不确定度的计算,结论以扩展不确定度U(k=2)来表示。 相似文献
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探索建立了溶解氧测定仪气态校准的检定方法。文中用通过对氧气的水-气平衡基础理论研究,论证了气态校准法在溶解氧测定仪检定过程中的可行性;运用大量的实验数据证明了各个检定参数的可操作性,为溶解氧测定仪提供了一种较为可行的检定方法。试验证明,该方法测量结果的不确定度小于0.2mg/L,优于同等条件下恒温水浴法测定结果的不确定度;且测量时间大为减少,提高了检定效率。 相似文献
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本文依据JJG 291-2008《覆膜电极溶解氧测定仪检定规程》,对溶解氧测定仪测量结果的不确定度评定进行分析。 相似文献
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《制冷与空调(北京)》2015,(7)
利用不确定度评定的方法对真空绝热管道单位漏热量的测试结果进行量化分析,找出影响真空绝热管道漏热量测量结果不确定度的主要因素,该因素出现在蒸发气体质量流量测量的环节,为提高测量结果的准确度,应首要考虑降低该参数在测试过程中的不确定度。 相似文献
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谷曼 《成组技术与生产现代化》2008,25(2):52-55
制动器综合性能的试验和检测是改善制动器制动性能不可或缺的一部分.文中对汽车制动器惯性试验系统进行了研究,利用机电设备及控制技术,设计了一种汽车制动器综合性能试验台,实现了汽车制动器实际工作状况的模拟与性能的测试. 相似文献
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Zhou Yang Unsong Pak Cholu Kwon Yimin Zhang 《Quality and Reliability Engineering International》2023,39(1):454-471
To decrease random parameters’ influence on the drum brake reliability, the reliability-based robust optimization design (RBROD) of the electric vehicle brake is proposed. Based on the assumption that the maximum temperature of the brake cannot exceed the allowable temperature, a performance function model of thermal–mechanical coupling reliability of drum brakes is established by the adaptive Kriging method, and the analysis of reliability sensitivity and RBROD are conducted. The accuracy of the proposed model is verified by temperature measurement experiment under emergency braking condition. The robust optimization design improves the drum brake reliability to 0.99998 and reduce the influence of the design parameters on the reliability, with the absolute values of the reliability sensitivity and the weight of the drum brake are significantly smaller. Therefore, the objectives of reliability design, robustness design, and optimization design are simultaneously achieved by the proposed methods. Besides, the relative error of the proposed method is 0.373%, the number of function evaluations is 39, and the comparison with four meta-model methods show that the proposed method holds high-accuracy and high-efficiency. This study provides a high-precision theoretical explanation for the robust optimization design of drum brake. 相似文献
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The performance of the Phase Metrics DFHT IV (DFHT) fly height tester was compared with the performance of the Zygo Pegasus 2000 (P2000) fly height tester. The testers showed comparable repeatabilities (0.25 nm for the DFHT and 0.30 nm for the P2000) and correlated well at all points except at the center rail trailing edge. The DFHT had a measurement uncertainty of 0.76 nm at a fly height of 25 nm and 0.35 nm near contact. Similarly the P2000 exhibited an uncertainty of 1 nm at 25 nm and 0.5 nm at contact. The measurement uncertainty of the DFHT is due to calibration at a location different from the measurement location; for the P2000, it is primarily due to residual uncertainty in the correction for stress-induced birefringence in the test disk. The P2000 did not recognize the presence of small diamondlike carbon bumps on the air bearing surface. There was a consistent 3-nm absolute offset between the fly height measurements of the two testers. Neither tester possessed a clear advantage over the other in the approaching era of near-contact recording. 相似文献
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分析了同一辆机动车在不同型号的制动台上由相同检验员检测,会得到不同的结果的原因。通过"机械"或"电子"方法对滚筒反力式制动检验台进行"模拟制动力"加载,经实验验证,是对滚筒反力式制动检验台原"静态检定"工作的一种有效、可靠的"完善"和"弥补"。通过"模拟制动力"加载试验,能发现滚筒反力式制动检验台或计算机联网中存在的问题。提出滚筒反力式汽车制动检验台在生产、使用中应注意的问题。 相似文献
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本文依据JJG908-1996滑板式汽车侧滑检验台检定规程和JJF1059-1999测量不确定度评定与表示,对滑板式汽车侧滑检验台示值误差测量结果进行了不确定度的评定,通过阐述测量过程中产生的各分量对测量结果的影响,得到了测量结果的扩展不确定度。 相似文献
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