- It used to be there was only one way to find a stud--poke a hole in the wall to see if it landed on one. This method was improved upon with magnetic stud finders--the theory being that where there is a stud, there is probably a nail. Using magnets to find studs is not only time consuming, it doesn't always work, unless there happens to be a nail in the vicinity of the stud you're passing the magnet over. A much more reliable method to find studs is to seek out changes in capacitance to determine where studs are.
- Electronic stud finders measure the dielectric constancy of a surface to determine whether an area is dense or hollow. A circuit inside the instrument detects the level of constancy and displays an alert when it notices variation.
- The latest stud finders use radar, utilizing short-range micro-powered radio waves to detect variation in density and heat underneath wallboard. A timing circuit supplies a sampling of echos that correspond with the alterations in the density of materials behind the wallboard.
