Abstract: A moldable unsaturated polyester resin composition having improved antishrinking and shape-retaining properties contains an unsaturated polyester resin/styrene mixture, fillers, glass fibers, an antishrinkage agent and a demolding agent, wherein the demolding agent is calcium montanate and wherein the antishrinkage agent is preferably a methyl methacrylate polymer. The composition is particularly useful for the manufacture of lamp reflectors having superior shape and weight retention integrity and reduced reflector surface fogging.

Abstract: The device according to the invention comprises a wide spectrum lighting source (60), a first interferometer (FP1) serving as a filter, a second interferometer (FP2) with the same characteristics as the first and a photodetector (66). The identity of the characteristics of the two interferometers makes it possible to work with higher lighting power levels than in the prior art. The two interferometers are advantageously constituted by a single apparatus used twice.Application to the measurement of the position, displacement or speed of a surface, particularly in detonics.