STP223: Nickel Depth Meter

    Linsey, G. D.
    Testing Methods Unit, Fuel Technology Sub-Section, Hanford Atomic Products Operation, Richland, Wash.

    Libby, H. L.
    Testing Methods Unit, Fuel Technology Sub-Section, Hanford Atomic Products Operation, Richland, Wash.

    Pages: 8    Published: Jan 1958


    Abstract

    In certain metallurgical processes, a layer of nickel about 0.001 in. thick is plated onto a relatively thick nonmagnetic base metal. There is often need to measure the thickness and uniformity of this thin layer of nickel by nondestructive methods. Magnetic methods which involve measuring the tension required to remove a magnet from the nickel plate are feasible but slow and difficult to use even under laboratory conditions. When the conductivity and permeability of the base metal and nickel differ, electromagnetic techniques based on eddy currents offer certain advantages. These techniques were applied to the successful development of the Nickel Depth Meter described here. This instrument (Fig. 1) can measure nickel thickness over a range of 0.1 to 2.0 mils within approximately 5 per cent under ideal conditions and has significantly reduced the time required for laboratory measurements of nickel plate thickness. The method of measurement is indirect and the accuracy depends much upon the uniformity of the electrical characteristics of the nickel and of the base metal.


    Paper ID: STP42011S

    Committee/Subcommittee: E07.03

    DOI: 10.1520/STP42011S


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