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另件的高精度测量通常是利用量块,以相对测量方法进行的,并且要求对各种测量误差分量,包括由于量块和另件的温度变形引起的误差,进行严格的评估.确定温度变形量△Tl的主要困难是因为缺少量块和另件制造材料的线膨胀温度系数(TKAP)的真实数值.众所周知,材料的线膨胀系数取决于它的化学成份及其热处理的金相组织和其它一些因素.以上所说线膨胀温度的系数数值都取自有关表格中,但是表列数值是对一定的温度范围而言的.并且所测量对象、仪器环节和据以测定线膨胀的那些试样等的化学成份和金相组织的情况,所知仅是近似的.因此由于所分析的材料物理、化学性质上的差异,表中所列出的TKAP的数值,一般地与其实际数值不完全相同,而且表中所列的一般是数值范围.
High-precision measurement of the other parts is usually carried out by using the measuring block with respect to the relative measuring method, and a strict evaluation is required for various measurement error components, including errors due to temperature deformation of the measuring block and the other parts. The main difficulty with the amount of ΔTl is due to the lack of real values for the coefficient of linear expansion of temperature (TKAP) of the material used for the gauge blocks and other components.It is well known that the linear expansion coefficient of a material depends on its chemical composition and its heat-treated metallographic structure and others Some factors. The values of the coefficient of linear expansion as mentioned above are taken from the tables concerned, but the values listed are for a given temperature range and the objects to be measured, the instrumental aspects and the samples from which the linear expansion is measured , Etc. The TKAP values listed in the table are generally not exactly the same as their actual values due to the physical and chemical differences of the analyzed materials , And the table is generally listed in the numerical range.