Thickness measurement of thin tape or wire material - is by counting beta radiation scattered back from moving material

摘要

A thickness measurement arrangement for thin layers of material in the form of tape or wire etc. has a beta radiation source illuminating the material as it moves past the source. Beta radiation reflected back off the material is counted in a tube behind the source. The arrangement is economical to make and well suited to the type of material measured. It eliminates disadvantages of similar systems such as slip-ring contacts and inaccuracies due to restricted measurement times. The measurement arrangement remains stationary. The material moves in a guide maintaining it at a fixed distance from the beta source. The characteristic aperture (D) of the beta detector inlet is related to the dia. (d) of the intersection surface of the beta radiation on the material by one of a number of ratios (D/d) e.g. 15 or 2.