Modification of the Philpot-Svensson method of recording refractive index gradients
Miroslav Miler, Jiří Sequens · Journal of Scientific Instruments · 1966
The Philpot-Svensson method of recording gradients of refractive index requires that the region observed be only a narrow section if the gradients are not identical from side to side of the object examined. A modification of the system has been used which enables several parallel sections to be examined simultaneously and without the cylindrical lens used by Philpot and Svensson. It has been applied to the examination of cooling channels in transformers.