Quantitative estimation of flaw height by radiographic testing. 3. Estimation of flaw height by application of a reference test specimen

We have already determined that the flaw height of a discoid flaw can be estimated using the radiographic contrast of the flaw, attenuation coefficient (μ) and the intensity ratio (n) of scattered to penetrated radiation at the sound area of a test specimen when the film-test specimen distance is set more than four times the anticipated flaw diameter. It is not easy, however, to obtain the values of μ and n. To overcome this inconvenience, we propose a reference test specimen (RTS), and in this paper describe the necessary conditions and usefulness of RTS. We can well estimate the flaw height using the densities at the sound area, flawed area and RTS. (author)