A stud finder is essentially a battery operated electromagnetic tool that detects the so called framing studs. Before there were stud finders either you pounded a small nail into the wall until you hit a stud or you used a small pivoting magnet.

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How stud finder works. Basically the radar in the stud finder shoots out a radio wave that bounces back once it reaches an object. Modern electronic stud finders operate by measuring the capacitance difference in the wall to identify where a wall is denser. They give you an amazingly accurate view into the wall and show you exactly where each stud is. As you would imagine this is an indispensable gadget when it comes to hanging a coat rack a shelf or any heavy duty object on the wall. Stud finder that utilizes a moving magnetic piston to locate studs under sheetrock plaster or tile. Its only too bad we can have them design one to find underground wiring.
How it works use a stud finder. When pointed at an empty wall the sound takes longer to bounce back than it does when it is in front of a stud. Theyre incredibly useful and you can find a huge range of them online. Will also locate steel studs. The magnet technique is slow. The magnet would help you find nails that had been driven into a stud.
Stud finders are little devices used to locate the beam of wood metal wiring running through drywall so you can find something strong to screw things too. If your project is valuable or heavy its best to use. They are normally handheld devices which are used to sense where the material behind the device is denser. Slide the stud finder across the wall and it will beep andor light up when it crosses a stud. A stud finder also stud detector or stud sensor is a handheld device used with wood buildings to locate framing studs located behind the final walling surface usually drywall. By measuring the electrostatic field of a wall and detect slight differences in the flow of electrons stud finders detect the relative change in density and thereby studs showing the best place to drive that nail.
Any stud finder will work well however they all work differently. Electronic stud finders changed all that. They also detect metal nails density changes and wires. A simpler stud finder. Another really cool product is the franklin prosensor 710 stud finder which can locate multiple studs at the same time and uses an array of leds to indicate the position of a wood or steel stud behind the drywall. The first technique works but it damages the wall.
A magnetic stud finder will read screws and nails behind the wall but whether or not these are dead center still requires some guesswork. This is the simplest most effective way to find studs.