Abstract: The pressure of a gas in a closed vessel can be non-destructively read by irradiating the closed vessel with x-rays. The irradiated gases in the vessel emit x-rays characteristic of various gases within the vessel. The characteristic x-rays, which pass out of the vessel, are discriminated and their intensity count converted to a pressure reading.

Abstract: An apparatus for measuring the plating thickness of a thin gold coating on a substrate such as a sheet or thin wire is described. The gold plating thickness, which may range from one to about one hundred and fifty microinches, is measured with an X-ray analysis technique in real-time as the plating of a wire is in process. The gold plated wire is exposed to X-rays of a type and intensity selected to stimulate X-ray emission from both the gold plating and the substrate with energies which permit energy-dispersive analysis. A ratio between the X-ray energies attributable to the substrate and gold plating is employed to determine the thickness of the gold plating with a generally applicable calibration curve. The accurate and rapid gold plating thickness measurement enables the monitoring the regulation of the gold plating thickness with a feedback control in a highly accurate manner.