This heat-mapping EMI probe will answer that question, with style. It uses a webcam to record an EMI probe and the overlay a heat map of the interference on the image itself.

Heat maps represent two-dimensional tables of numbers as shades of colors. This is a popular plotting technique in biology, used to depict gene expression and other multivariate data. The dense ...

This heat map looks like a work of art, but it actually shows the age of buildings in the Portland, Ore. area. About 544,000 structures are represented, ...