Introduction:

Industry’s current emphasis on improving control quality sometimes implies that the importance of measurement is overlooked. However, measurement is the first requisite of any control scheme. Lord Kelvin once summarized the significance of measurement science: “If you can measure that of which you speak and can express it by a number, you must know something of the subject. But, if you can not measure it, your knowledge is meager and unsatisfactory—measurement is the basis of all knowledge.” If you cannot measure, you cannot control.