Realistic evaluation of the precision and accuracy of instrument calibration systems

Calibration of ins trumen ts and standards is a refined form of measurement. Meas ur eme nt-of some property of a thing is an operation t hat yields as an end res ult a number t hat indicates how much. of the proper ty t he t hing has. Measuremen t is ordinarily a repeatable oper atIOn, so t hat It IS appropJ'latc to r egard m eas urement a s a production process, t he "product" bein g t he numbers, i .e ., t he measurements, t hat it y ields; a nd to apply to measuremen t processes in t he la borator y the con ce p ts a nd techniques of statistical process control t hat h ave prove d so useful in the quality con trol of indu st ri al production.