计量学的基本理论指出，X射线机不具有计量器具的属性。国家的计量法规并未将X射线机定为计量器具。目前存在的JJG 40—2001《X射线探伤机》检定规程，将X射线探伤机与X射线检测技术相互混淆，将X射线探伤机的某些技术性能，说成所谓的X射线探伤机的“计量性能”，不仅违反计量学基本理论，而且也不符合射线检测技术实际。从计量学理论和射线检验实际经验只能得到X射线机不是计量器具的结论。

It was proved that X-ray apparatus is not measuring instruments by the basic and general theory of metrology. X-ray apparatus is not regarded as measuring instruments in the national code of metrology. It is misleading that the X-ray apparatus is confused with X-ray radiography and some technical specifications of X-ray apparatus are described as the characteristics of measuring instruments by subjective idea in the inspection procedures of JJG 40—2001. The mistakes not only infract the basic theory of metrology,but also depart from the X-ray radiographic testing process.The conclusion is only that X-ray apparatus is not measuring instruments which should be reach out by the theory of metrology and the radiographic practice.