Abstract: A backscatter measurement device for measuring the thickness of a coating on a strip of substrate material moving from a feed supply to a take up location at a predetermined speed. A measurement wheel is provided on the rim of which are mouted backscatter probes for irradiating and detecting the backscattered radiation from the coated substrate. The coated strip of substrate material is threaded around the outer surface of the rim. The measurement wheel is rotated at a speed such that the tangential speed of a point on the rim equals the speed of the moving strip whereby the probe and an adjacent point on the strip are stationary relative to one another while the point on the strip is adjacent the rim. Thus thickness measurements may be taken without stopping the movement of the coated strip.

Abstract: A backscatter measurement device for measuring the thickness of a coating on elements forming a web of substrate material moving from a feed supply to a take-up location at a predetermined speed. A measurement wheel is provided, adjacent to the rim of which is mounted a backscatter probe for irradiating and detecting the backscattered radiation from a coated substrate. The web of substrate material is threaded around the outer surface of the rim. The measurement wheel is rotated at a speed such that the tangential speed of a point on the rim equals the speed of the moving web whereby the probe and an adjacent point on the web are stationary relative to one another while the point on the web is adjacent the rim. Thus thickness measurements may be taken without stopping the movement of the coated web. This backscatter measurement device is further provided with indexing apparatus to position automatically the probe directly adjacent an element to be measured on the web.

Abstract: An improved backscatter instrument for the nondestructive measurement of coatings on a substrate. A memory having selectable memory areas, each area having stored intelligence available which is determinative of the shape of a functional plot of coating thickness versus backscatter counts per minute unique for each particular combination of emitting isotope, substrate material, coating material and physical characteristics of the measuring instrument. A memory selector switch connects a selected area of memory to a microprocessor operating under program control whereby the microprocessor reads the intelligence stored at the selected area and converts the backscattered count of the coating being measured into indicia of coating thickness.

Abstract: A backscatter measurement device for measuring the thickness of a coating on a strip of substrate material moving from a feed supply to a take up location at a predetermined speed. A measurement wheel is provided on the rim of which are mounted backscatter probes for irradiating and detecting the backscattered radiation from the coated substrate. The coated strip of substrate material is threaded around the outer surface of the rim. The measurement wheel is rotated at a speed such that the tangential speed of a point on the rim equals the speed of the moving strip whereby the probe and an adjacent point on the strip are stationary relative to one another while the point on the strip is adjacent the rim. Thus thickness measurements may be taken without stopping the movement of the coated strip.

Abstract: An improved beta backscatter instrument for the non-destructive measurement of the thickness of thin coatings on a substrate. Included therein is the utilization of a bank of memory stored data representative of isotope, substrate, coating material and thickness range characteristics in association with a control card having predetermined indicia thereon selectively representative of a particular isotope, substrate material, coating material and thickness range for conditioning electronic circuit means by memory stored data selected in accord with the predetermined indicia on a control card for converting backscattered beta particle counts into indicia of coating thickness.

Abstract: Control card receiving and sensing assembly including a fixed base plate, a generally U-shaped cover member mounted thereon and card entry defining means of a character such as to permit card insertion therebetween and removal therefrom only under conditions where essentially zero force is exerted on the card control surfaces.

Abstract: An improved electrode construction for apparatus for testing the integrity of thru-hole plating in printed circuit boards and the like by measuring the effective thickness thereof. A first conically shaped electrode assembly is adapted to be displaced along a predetermined path into engagement with one of the defining marginal perimetric edges of a plated thru-hole in a circuit board. A second and complementally shaped electrode assembly is adapted to be displaced into engagement with the other defining marginal perimetric edge of the thru-hole. Each of such electrode assemblies includes a pair of discrete selectively contoured electrode elements adapted to make line contact with the marginal defining edges of the thru-hole, whereby a predetermined magnitude of constant current can be passed through the plating intermediate one pair of electrode elements, and the voltage drop developed thereby across the thru-hole plating measured by the other pair of electrode elements.