It has been known that unnecessary electromagnetic field noises (hereinafter, simply referred to as noises) generated from electronic, information, communication, and industrial devices influence adversely, such as malfunction, on other electronic devices.
Further, it has been concerned that noises give some influences to a human body, and the influences given by noises have been studied.
In order to specify such invisible noise generation source, it is effective to visualize noises. Hitherto, devices to visualize noises have been proposed (refer to Patent Literatures 1 to 3).
For example, a device disclosed in Patent Literature 1 creates a diagram in which the respective electromagnetic field intensities (signal levels) of noises are displayed in a color on a two-dimensional surface. A device disclosed in Patent Literature 3 performs frequency analysis of noises on the surface of a measured object, and creates a contour map of noises of a specific frequency.
A device disclosed in Patent Literature 2 determines the position of a sensor in a three-dimensional space around a measured object by parallax, and displays the respective electromagnetic field intensities (signal levels) of noises at the position in a color. Accordingly, a measurer can acquire information on the noises at the position of the sensor.