Beta radiation thickness gauge

These are unstable forms of elements which decay by the emission of radiation. A radioactive isotope of an element behaves chemically in the same way as the non-radioactive form, but its radiation may be detected and measured by a suitable instrument. In the rubber industry radioactive isotopes are used in beta ray thickness gauges, in studying the precise role of sulphur in vulcanisation, in the speedy determination of tread wear in tyres, etc. See Beta Rays. 

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