MEASUREMENT OF THICKNESS OF METAL COATING AND COMPONENT OF ANOTHER METAL IN THE COATING FILM

摘要

PURPOSE:To solve preset simultaneous equations on the basis of two measured values thereby to effect the simultaneous and non-destructive measurements by catching an fluorescent X ray from a metal layer with two kinds of different extraction angles and by respectively measuring the intensities of the X rays having such a frequency as is determined by the composition of the metal coating film. CONSTITUTION:A zinc-plated steel plate 10, which has been subjected to alloy treatment, is horizontally conveyed in the direction of arrow on a continuously conveying line 1. Above the line 1, an X-ray generating tube 2 is provided to irradiate a radioactive ray toward the steel plate 10 so that the fluorescent X-ray is detected from the steel plate 10 at an extraction angle different from that of a detecting element 3 at U. The detecting element 3 and 4 generate pulses, which have such peak values as are proportional to the intensity of the X-rays incident thereon, and these pulses are amplified to a preset level each by an amplifier 5. The amplified outputs are subjected to selection by peak selectors 61 and 62 thereby to select the pulses having preset peak values so that the numbers of the pulses is counted by each of counting circuits 71 and 72 to detect the intensity of the characteristic X-ray of ZnKa. The outputs of the circuits 71 and 72 are fed to an arithmetic circuit 8, and preset simultaneous equations are solved so that the plating thickness and the alloy degree and determined and displayed in the display unit 9.