Stud finder

A stud finder, also stud finder is a device for finding wood or metal beams in walls.

Types

There are main types of this device:

  • The first type uses a small magnet, of the nails or screws seen in the beams, which have been used during preparation of the wall for their attachment.
  • The second type uses an internal capacitor to ( Dielectric conductivity) determine change of permittivity of the wall, while the user moves the device over the surface of the wall. A significant change in the dielectric conductivity indicated a dense object behind the wall, usually a stand framing. Stud finder with internal capacitor are very widespread.

Stud finder with internal capacitor can be divided into two classes:

  • Edges viewfinder register the edges of the beam or other objectives behind the wall. The sensor is an edge detector detects when it is directly over a change in density, such as the edge of a beam. Edge detection have both the right and left are moved over the wall to find both edges, so that the center can be found. The first stud finder with internal capacitor was an edge finder and the most inexpensive models still are.
  • Center viewfinder recognize the middle of the bar. These tools record the permittivity using a plurality of sensors and use the different measured values ​​to determine the position of the center of the target. Unlike edges viewfinder this viewfinder beam need to be moved only in one direction to indicate the center of the beam. This type of bar examiners are also called one-step viewfinder.

Stud finder with internal capacitor can also contain functions that allow them to find metal and is under power lines.

Development of models with internal capacitor

The stud finder with internal capacitor was first designed by Robert Franklin in 1977. After he had patented this device, he tried the manufacturing rights to several major tool manufacturer for sale, all rejected the idea. He took his prototype to Zircon Corporation, an electronics manufacturer in Campbell, California, which was agreed to produce and market the device. Zircon was for the duration of the patent term (until 1998) the only producer of bar examiners with internal capacitor. Then the patent expired and other companies were also allowed to manufacture this device.

Girder
101442
de