一、引言几年来,为更好地控制机械工业产品的质量,建立了许多国家检定机构。很多工业产品的质量,依赖于一定物理量的准确测量,而这种测量是靠与标准比较进行的。对标准的量值必须知道其准确度。为满足后者的要求,计量检定中心(以下简称检定中 I. INTRODUCTION In the past few years, in order to better control the quality of machinery and industrial products, many national accreditation agencies have been established. The quality of many industrial products relies on the accurate measurement of certain physical quantities, which are measured against the standards. The standard value must know its accuracy. To meet the latter’s requirements, metrology test center (hereinafter referred to as the test