Plans to build a hand held plastic box with analog meters detects relative level of positive or negative charge fields. This unit is sensitive enough to detect the minute charge produced by just rubbing a piece of plastic and bringing the probe in proximity. It easily measures the electric field during a thunder storm or other high static conditions. Extremely useful for mapping the electric fields associated with high voltage generators or indicating dangerous fields when using sensitive electronic circuits or components. Unit is enclosed in a 5 x 2 x 1" plastic box with a telescoping antenna probe. Contains a sensitivity /power switch and over power LED useful in indicating dangerous electric fields. Basic unit is made for detecting negative ions but in a pinch can be used for positive detection simply by holding the probe antenna and using the circuitry as the pick up probe. IOD1 - Plans Only.