Probe - Planar
The planar probe calculates the magnetic field on a flat grid and plots contours a specified function of the magnetic field. To make a planar probe choose menu command
Config > Make probe > Planar
This will create the probe and bring up its the edit window. You will be asked for a name for the probe; enter it and close the name dialog. On the edit window the Axes tab is where you define the size of the calculation grid:
Axes tab
The screen snapshot below shows the specification of a 5 by 10 point calculation grid that is 0.5m in the x direction by 1m in the z direction:
The calculation grid is a planar grid in the 3-d configuration space, specified by two displacement vectors u and v. The four corners of the grid relative to the origin of the coordinate system of the probe are the origin itself, u, v, and u+v. Two numbers nu and nv are used to specify the subdivision of this grid. There are nu points in the u direction, nv points in the v direction, for total number of measurement points of nu*nv.
| parameters | meaning |
|---|---|
| ux,uy,uz | components of u vector |
| vx,vy,uz | components of v vector |
| nu,nv | number of points in u and v directions |
The lengths ux,uy,uz,vx,vy,vz may have units. If no units are specified then lengths are assumed to be in meters.
The number of grid points includes the ends of the grid. Therefore, to make a grid 10mm wide with 1mm spacing we would set ux to 10mm and nx to 11.
Position tab
As for any object, the Position tab allows you to position and orient the grid in space.
Looks tab
The Looks tab allows you to change the appearance of the contours on the configuration window, whether or not you wish to see the grid lines, etc.
Plot tab
By default the contours of field magnitude B are plotted on the configuration window. You can change which quantity is contoured on the Plot tab of the edit window. Available quantities include components and magnitude of the magnetic vector potential (A), components and magnitude of the magnetic flux density (B), components of the magnetic gradient tensor (dBdx, dBdy, etc.), and the macro result (f). Only one quantity may plotted at a time.
Quantities min and max are the minimum and maximum values for which contours will be drawn. If you check the autoscale checkbox then these quantities will update to reflect the full range of calculated values whenever the magnetic field is recomputed.
The quantity contour is the contour spacing. If you enter 0 in this box, then the contour spacing will be one-tenth of the range between min and max. Contours are plotted at min, min+contour, min+2*contour, and so on.
The contours will be plotted on the configuration window. You can also have the contours plotted in a separate window by ticking the checkbox on the Plot tab of the edit window.
Macro tab
A macro language function can be specified on the Macro tab of the edit dialog. To plot the result of the evaluation of the macro, select f on the Plot tab.
The macro may be used to plot field lines.