Apparatus for detecting flaws in transparent containers

摘要

A method and apparatus are provided for testing containers such as glass bottles. The container is filled with an opaque material and then immersed in a bath having two parallel walls of light transmitting material. The bath contains a light transmitting liquid having a refractive index comparable with that of the material of the container and a light transmitting efficiency different from that of the material of the container. Light is projected through the parallel walls of the bath to illuminate the walls of the container so that the wall thickness is clearly visible and the distribution of wall thickness can be studied.