Thermal-insensitive moiré interferometry.
An optical arrangement has been devised that will permit the measurement of one component of the relative displacement, and therefore the corresponding strain, in a surface at nonambient temperatures by use of coherent optics. The method is based on the technique of moiré interferometry with illumination at grazing incidence. A demonstration of principle is described, with the beams passing through the flame of a blowtorch.
McKelvie
J
J