07. Surface Coils - Small Spherical Flaw (SF-DEF1.EXE)

A download for SF-DEF1.EXE is available. To use it, download the SF-DEF1.EX_ file and rename it to SF-DEF1.EXE. This program will only run on PC computers with operating systems from MS-DOS to Windows XP. It does not run on PCs with Windows 7 operating system unless an MS-DOS emulator program like "DOS-Box" is installed.

All units are MKS.

SF-DEF1.EXE calculates the CHANGE in induced voltage in a surface transmit-receive coil configuration due to a small spherical flaw in a nearby plate. The radius of the spherical flaw is 1E-4 m (0.1 mm). This program can account for the influence of eddy current and magnetic field in two lower plates and one upper plate as well as calculate a flaw signal in any of these plates as well. The plates have finite thickness, but they are assumed to have infinite radial extent. The plate materials are assumed to be linear, homogeneous and isotropic with user defined electrical conductivity and relative magnetic permeability.

This program only accounts for the interaction of the eddy current with the flaw, not a magnetic field interaction like in ferromagnetic materials. Therefore, the flaw signal calculation should only be considered valid if the flaw is in a NONMAGNETIC plate.

An impedance coil signal can be simulated by giving the receive coil the same physical dimensions of the transmit coil, and by making the centre-to-centre separation between the coils near zero (say ~ 1E-10 m or 1 Angstrom).

SF-DEF1.EXE generates a ".dat" file with real and imaginary voltage components. The program also generates a ".val" file with text information on the user input parameters defining the configurations that were solved.