[转发]不确定度--不确定度之所以重要的原因

Why is it important? 不确定度之所以重要的原因?

The uncertainty is a quantitative indication of the quality of the result. It gives an answer to the question, how well does the result represent the value of the quantity being measured?
不确定度是结果质量的定量性指标，它回答了以下问题，即结果如何恰当地代表测量的量值？
It allows users of the result to assess its reliability, for example for the purposes of companson of results from different sources or with reference values. Confidence in the comparability of results can help to reduce barriers to trade.
它允许结果的用户评定其可靠性，比如为了比对来源不同的结果或者与参考值进行比对。对结果相似性的置信水平能够降低贸易壁垒。
Often, a result is compared with a limiting value defined in a specification or regulation. In this case, knowledge of the uncertainty shows whether the result is well within the acceptable limits or only just makes it.
通常，一个结果要与标准或者规定中的一个设定限值相比较。这种情况下，不确定度就能显示出结果是否正好落在可接受范围内或者仅为临界值。

Occasionally a result is so close to the limit that the risk associated with the possibility that the property that was measured may not fall within the limit, once the uncertainty has been allowed for, must be considered.
有时候一个结果如此之接近限值，以至于与被测量性质的可能性有关的风险不会落在限值内。一旦不确定度被认可，则必须予以考虑。
Suppose that a customer has the same test done in more than one laboratory, perhaps on the same sample, more likely on what they may regard as an identical sample of the same product. Would we expect the laboratories to get identical results? Only within limits, we may answer, but when the results are close to the specification limit it may be that one laboratory indicates failure whereas another indicates a pass. From time to time accreditation bodies have to investigate complaints concerning such differences. This can involve much time and effort for all parties, which in many cases could have been avoided if the uncertainty of the result had been known by the customer.

假设一个客户在一个以上的实验室内做完同样的检测，可能检测一个样品，更可能是检测相同产品的相同样品。我们会期待实验室获得同一个结果吗？只有在限值内我们才能这么回答，但是当结果与标准值接近时，也许一个实验室指示出错，而另一个则显示通过检测。有时，认证机构必须调查与这些差别有关的错误。对各方来说这会牵涉许多时间和精力，如果客户已经了解结果的不确定度，大多数情况下就可以避免时间和精力的浪费。

How does it arise? 不确定度的产生原因?

Any measurement is subject to imperfections; some of these are due to random effects, such as short-term fluctuations in temperature, humidity and air-pressure or variability in the performance of the measurer. Repeated measurements will show variation because of these random effects. Other imperfections are due to the practical limits to which correction can be made for systematic effects, such as offset of a measuring instrument, drift in its characteristics between calibrations, personal bias in reading an analogue scale or the uncertainty of the value of a reference standard.
任何测量都是非理想性的，部分是因为温度、湿度和气压或者测量者的操作变动性等因素在短期内的波动等这些随机效应。有了这些随机效应的影响，重复测量就可以显示出数值的变化。其它非理想性因素是由于对系统效应的修正产生的实际限制，比如测量仪器的误差，两次校验之间的性质偏移，个人读取量数的偏差或者参考标准值的不确定性。

What is uncertainty? 什么是不确定度?

I used to be uncertain - now I#m not so sure. In ordinary use the word #uncertainty# does not inspire confidence. However, when used in a technical sense as in #measurement uncertainty# or #uncertainty of a test result# it carries a specific meaning. It is a parameter, associated with the result of a measurement (eg a calibration or test) that defines the range of the values that could reasonably be attributed to the measured quantity. When uncertainty is evaluated and reported in a specified way it indicates the level of confidence that the value actually lies within the range defined by the uncertainty interval.
从技术角度讲，不确定度是指测量的不确定性或者具有特殊含义的检测结果的不确定性。它是一个与测量结果相联系（比如校验或者检测）的参数，定义了所得值的范围，可能跟检测数量有关。当评定不确定度并以特定方式给出报告时，它即指落在规定的不确定区间范围内的数值的置信水平。