量度

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量度仲翻譯緊。歡迎你積極翻譯同修訂
不同嘅錶
不同嘅錶

量度喺指用同樣單位去估計不同比率數量的大小同嘅過程。量度喺個過程嘅結果,以一個實數和單位去表示,而個實數叫做比率。例如9米,就喺以去估一舊嘢嘅相對長度。

量度喺同標準去比較(A measurement is a comparison to a standard.) -- 蕭克 萊en:William Shockley
By number we understand not so much a multitude of Unities, as the abstracted Ratio of any Quantity to another Quantity of the same kind, which we take for Unity. -- 牛頓 (1728)

目錄

[編輯] 引言

量度喺特定情況下,使用儀器去獲得事物跟標準單位比較所得嘅數據。量度儀器如溫度計、車速錶、磅同電壓錶等。為咗準確量度,儀器必須好好校準同使用。但是,所有量度結果都有某一程度偏差,叫做標準誤差。咁意味住,喺每次量度都有三部分,其中有一個數字跟住單位之後;三部分是估計數據、誤差範圍同實際數據可能喺誤差區域之間。例如木板度到嘅9 米長度可以有0.95可能性有0.01米嘅正負偏差。

量度同數數喺不同嘅。量度是一個實數兼且嘅不準確。而數數喺個自然數,可能也許喺準確。例如我們數到一間屋有十個人居住。量度喺科學嘅根本,包括物理、化學和生物。量度在工商業應用也十分重要,譬如工程學、建築、製造業、配藥生產和電子。

[編輯] 量度單位和系統

主文: 量度單位 同 量度系統

Because measurement involves the estimation of magnitudes of quantities relative to particular quantities, called units, the specification of units is of fundamental importance to measurement. The definition or specification of precise standards of measurement involves two key features, which are evident in the International System of Units (SI). Specifically, in this system the definition of each of the base units makes reference to specific empirical conditions and, with the exception of the kilogram, also to other quantitative attributes. Each derived SI unit is defined purely in terms of a relationship involving itself and other units; for example, the unit of velocity is 1 m/s. Due to the fact that derived units make reference to base units, the specification of empirical conditions is an implied component of the definition of all units.

The measurement of a specific entity or relation results in at least two numbers for the relationship between the entity or relation under study and the referenced unit of measurement, where at least one number estimates the statistical uncertainty in the measurement, also referred to as measurement error. Measuring instruments are used to estimate ratios of magnitudes to units. Prior comparisons underlie the calibration, in terms of standard units, of commonly used instruments constructed to measure physical quantities.

[編輯] 計量學

計量學喺量度嘅學科。 In general, a metric is a scale of measurement defined in terms of a standard: i.e. in terms of well-defined unit. The quantification of phenomena through the process of measurement relies on the existence of an explicit or implicit metric, which is the standard to which measurements are referenced. If one says I am 5, that person is indicating a measurement without supplying an applicable standard. He could mean I am 5 years old or I am 5 feet high, however the implicit metric is that he is 5 years old.

[編輯] 量度歷史

主文: 量度歷史

Laws to regulate measurement were originally developed to prevent fraud. However, units of measurement are now generally defined on a scientific basis, and are established by international treaties. In the United States, commercial measurements are regulated by the National Institute of Standards and Technology NIST, a division of the United States Department of Commerce.

The history of measurements is a topic within the history of science and technology. The metre (us: meter) was standardized as the unit for length after the French revolution, and has since been adopted throughout most of the world. The United States and the UK are in the process of converting to the SI system. This process is known as metrication.

[編輯] 機率量度

Measurement is not limited to physical quantities and relations but can extend to the quantification of a magnitude of any kind. In the social sciences and other fields such as health, biology and market research, probabilistic models such as the Rasch model for measurement are applied in order to measure using instruments such as questionnaires and assessments which enable comparisons between persons. The field of psychometrics is concerned with the theory and technique of measurement of psychological and mental phenomena.

[編輯] 困難之處

因為有好大嘅誤差,量度不同嘅數據就變咗好困難。 有啲量度困難來自事物嘅偏差,有啲就由於時間所限提高量度嘅難度以下就係喺一啲難以量度嘅例子,其中包括社會相關項目譬如:

獲得準確嘅物理量都喺難事。喺世上係完全無可能得到一個絕對嘅量度結果,相反,多次量度會因為有不同因素影響量度結果好似溫度、時間、電場. 尤其是量度方法。例如量度光速,而家就有技術去準確量度,但係呢啲技術就為量度所得嚟結果有不穩定性。例如使用統計技巧就可以量度速度。喺量度初段,可變性較高, and comparing the results shows that the variability and bias in the measurement methods was not properly taken into account. Proof of this is that when various group's measurements are plotted with the estimated speed and error bars showing the expected variability of the estimated speed from the actual number, the error bars from each of the experiments did not all overlap. 即係話誤差直正來源同誇張量度係由於好多嘅錯誤形成。

[編輯] 另一定義

除以上定義之外,量度亦經常應用在搜集一件事物發展程度改變嘅過程。例如由採集、處理原始數據也是量度一種,例子如消費者信心同物價升跌。

[編輯] 其他

量度結果嘅比率在物理重要部分。重要物理量包括:

[編輯] 參閱

[編輯] 參考

Newton, I. (1728/1967). Universal Arithmetic: Or, a Treatise of Arithmetical Composition and Resolution. In D.T. Whiteside (Ed.), The mathematical Works of Isaac Newton, Vol. 2 (pp. 3-134). New York: Johnson Reprint Corp.

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