Abstract: An apparatus and method to measure different properties of a liquid film or coating traveling or resting on a horizontal support, including dynamic viscosity, dynamic surface tension and surface dilational elasticity, the apparatus comprising: a series of wires placed above a moving wet film or coating to which high voltage is applied inducing an electrostatic field that lifts the free surface of said film preferentially near the wires; a means for detecting the free surface displacement of the free surface in the section where the voltage is applied to the coating, possibly the means being a CCD camera coupled to a digital acquisition system; and means for processing the signal to determine the properties of the coating.

Abstract: A metal vapor laser which has an optical cavity, and a sputtering cell arranged at one end. The sputtering cell has a sputtering surface for sputtering metal deposited on the surface or from which the surface is formed. A gas stream is introduced into the cavity for entraining the sputtered metal into a metal vapor beam and the gas stream is introduced such that the gas stream flows substantially parallel to at least a part of the sputtering surface to ensure that the passage for introducing the gas is aligned correctly relative to the sputtering surface, there is provided an insulative ring formed in two portions defining the passage therebetween and the first portion of the ring is moveable with respect to the second portion thereof to align a passage. Two sources of gas are provided for forming the gas stream and are selectively switched so that each source of gas can be selectively coupled to the cavity for forming a gas stream of a particular variety of gas.