由于铁路车轴通常测量的直径都在6英寸以上,因此,温度补偿对于车轴的制造和修理都有很大的关系。对于某些工件来说,仅相差几度的未经补偿的温度变化,就可能使之接近或超过规定公差。采用新的技术,在尺寸测量上紧密公差的重复性已得到显获改善。然而误差虽然很小但总还是存在的。因此,在检测仪器方面的改进,只能减少不精确的程度。更高的精度尚不能纳入标准,原因是 Since railroad axles usually measure more than 6 inches in diameter, temperature compensation has a strong bearing on the manufacture and repair of axles. For some workpieces, an uncompensated temperature change of only a few degrees may bring it closer to or exceed the specified tolerances. With new technology, repeatability of close tolerances in dimensional measurements has been improved. However, the error is small but still exists. Therefore, improvements in instrumentation can only reduce the degree of inaccuracy. The higher the accuracy can not yet be included in the standard, the reason is