Post by thread:[OT]: How does a wall "Stud Finder" work?

Very short range Radar. Look at the Lawrence Livermore Lab web site. It is very clever. w.. Kevin Fisk wrote: {Quote hidden}> > Anyone out there know how a wall "Stud Finder" works? I imagine a coil > with some sort of level detection but I am curious. > > Cheers, > > Kevin > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

yeah coil and a very sensitive circuit.. this is the right and the only way Tal -----Original Message----- From: pic microcontroller discussion list [spam_OUTPICLISTTakeThisOuTMITVMA.MIT.EDU]On Behalf Of Kevin Fisk Sent: Monday, February 18, 2002 9:18 PM To: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU Subject: [OT]: How does a wall "Stud Finder" work? Anyone out there know how a wall "Stud Finder" works? I imagine a coil with some sort of level detection but I am curious. Cheers, Kevin -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

I can see how that would work for a steel stud. But wood? David On Mon, 18 Feb 2002 21:38:49 +0200 Tal Bejerano - AMC <kooterKILLspamZAHAV.NET.IL> wrote: {Quote hidden}> yeah coil and a very sensitive circuit.. > this is the right and the only way > > Tal > > -----Original Message----- > > Anyone out there know how a wall "Stud Finder" works? I imagine a coil > with some sort of level detection but I am curious. > > Cheers, > > Kevin -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

wood studs in wall? maybe plastic, then no coil help :-) -----Original Message----- From: pic microcontroller discussion list [.....PICLISTKILLspam.....MITVMA.MIT.EDU]On Behalf Of David Koski Sent: Monday, February 18, 2002 10:06 PM To: EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU Subject: Re: [OT]: How does a wall "Stud Finder" work? I can see how that would work for a steel stud. But wood? David On Mon, 18 Feb 2002 21:38:49 +0200 Tal Bejerano - AMC <kooterspam_OUTZAHAV.NET.IL> wrote: {Quote hidden}> yeah coil and a very sensitive circuit.. > this is the right and the only way > > Tal > > -----Original Message----- > > Anyone out there know how a wall "Stud Finder" works? I imagine a coil > with some sort of level detection but I am curious. > > Cheers, > > Kevin -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

They pick up screws and nails >>> @spam@kooterKILLspamZAHAV.NET.IL 02/18/02 03:13PM >>> wood studs in wall? maybe plastic, then no coil help :-) Subject: Re: [OT]: How does a wall "Stud Finder" work? I can see how that would work for a steel stud. But wood? David > Tal > Anyone out there know how a wall "Stud Finder" works? I imagine a coil > with some sort of level detection but I am curious. > Cheers, > Kevin -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Thanks Walter, I looked and came up with MIR. Very cool. Incidentally I had a moment of brilliance (or rather the opposite) and went onto Google and typed (amazingly) "Stud Finder Circuit" and came up with... http://www.howstuffworks.com/question271.htm Title: I have an electronic stud finder and I am amazed at how well it works. How does it know where the studs are? Sorry for bothering the list - should have had this moment of 'brilliance' first. Cheers, Kevin Walter Banks wrote: {Quote hidden}> Very short range Radar. Look at the Lawrence Livermore Lab > web site. It is very clever. > > w.. > > Kevin Fisk wrote: > >>Anyone out there know how a wall "Stud Finder" works? I imagine a coil >>with some sort of level detection but I am curious. >> >>Cheers, >> >>Kevin >> >>-- >>http://www.piclist.com hint: The PICList is archived three different >>ways. See http://www.piclist.com/#archives for details. >> > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Differential Capacitance. Basically 3 plates in a row hooked up to monostables. The difference in capacitance between the middle and outter plates is sensed and displayed. Stud finders also find patches in wallboard because the repair has a different dielectric constant than normal wall. Great invention. Can find pipes and wires too, if they're close enough to the wall. Zircon also has a micropower radar based unit for use in concrete. Has a PIC in it <G>. Robert Tal Bejerano - AMC wrote: > > wood studs in wall? maybe plastic, then no coil help :-) > > {Original Message removed}

I have seen designs for 3 different methods. All are based on a small change in the received signal. You "calibrate" to a non-stud position & then a small change from this can be used to identify a stud. Ultrasonic - Uses the reflection phase shift I think Capacative - Uses the small difference in diaelectric constant to detect the higher density material behind the cladding. Inductive - Uses the change in Loss angle - I think - to determine the position. For metal studs, some cable locators can also be used I believe. Richard P I can see how that would work for a steel stud. But wood? David On Mon, 18 Feb 2002 21:38:49 +0200 Tal Bejerano - AMC <KILLspamkooterKILLspamZAHAV.NET.IL> wrote: {Quote hidden}> yeah coil and a very sensitive circuit.. > this is the right and the only way > > Tal > > -----Original Message----- > > Anyone out there know how a wall "Stud Finder" works? I imagine a coil > with some sort of level detection but I am curious. > > Cheers, > > Kevin -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

These 'stud finders' actually find studs - they work on the principle that a piece of drywall with a stud it behind presents a much different dielectric constant than a piece of drywall without dry wood behind it. An oscillator is constructed such that at least some portion of both plates of a capacitor that comprise part of a tuned circuit are presented to the wall. A 'reference null' is established first on a piece of drywall that does not have wood behind it - then a search for a stud can commence. Jim ----- Original Message ----- From: "Tal Bejerano - AMC" <RemoveMEkooterTakeThisOuTZAHAV.NET.IL> To: <spamBeGonePICLISTspamBeGoneMITVMA.MIT.EDU> Sent: Monday, February 18, 2002 2:13 PM Subject: Re: [OT]: How does a wall "Stud Finder" work? > wood studs in wall? maybe plastic, then no coil help :-) > > > {Original Message removed}

You're right! http://www.howstuffworks.com/question271.htm Rick Jim wrote: {Quote hidden}> These 'stud finders' actually find studs - they > work on the principle that a piece of drywall > with a stud it behind presents a much different > dielectric constant than a piece of drywall > without dry wood behind it. > > An oscillator is constructed such that at least > some portion of both plates of a capacitor that > comprise part of a tuned circuit are presented > to the wall. > > A 'reference null' is established first on a > piece of drywall that does not have wood > behind it - then a search for a stud can > commence. > > Jim > > ----- Original Message ----- > From: "Tal Bejerano - AMC" <TakeThisOuTkooterEraseMEspam_OUTZAHAV.NET.IL> > To: <RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU> > Sent: Monday, February 18, 2002 2:13 PM > Subject: Re: [OT]: How does a wall "Stud Finder" work? > > > wood studs in wall? maybe plastic, then no coil help :-) > > > > > > {Original Message removed}

You bought a 'nail finder'. The question now is - how dead-on was the nail to the stud? Jim ----- Original Message ----- From: "Larry Williams" <EraseMEwizzzardBELLSOUTH.NET> To: <RemoveMEPICLISTEraseMEEraseMEMITVMA.MIT.EDU> Sent: Monday, February 18, 2002 8:49 PM Subject: Re: [OT]: How does a wall "Stud Finder" work? {Quote hidden}> The one I bought consists of a magnet on a pointer. Move the thing > around, find a nail, stud found! > > David Koski wrote: > > > > I can see how that would work for a steel stud. But wood? > > > > David > > > > On Mon, 18 Feb 2002 21:38:49 +0200 > > Tal Bejerano - AMC <RemoveMEkooterspam_OUTKILLspamZAHAV.NET.IL> wrote: > > > > > yeah coil and a very sensitive circuit.. > > > this is the right and the only way > > > > > > Tal > > > > > > -----Original Message----- > > > > > > Anyone out there know how a wall "Stud Finder" works? I imagine a coil > > > with some sort of level detection but I am curious. > > > > > > Cheers, > > > > > > Kevin > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Mon, 18 Feb 2002, Larry Williams wrote: > The one I bought consists of a magnet on a pointer. Move the thing > around, find a nail, stud found! Unfortunately if someone like me nailed up the drywall, you may have just found one edge of said stud. Fortunately I don't build houses for a living. I prefer the cpacitive/inductive/whatever type that finds the edges and the middle of the stud. Dale -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

I didn't build it, just bought it to see if it worked. Give the people that built it the grief. Someone asked how they worked. I had one, that's how it worked, I responded with the low tech info I had. I guess you could tack a pic to the pointer and make it work better. Dale Botkin wrote: {Quote hidden}> > On Mon, 18 Feb 2002, Larry Williams wrote: > > > The one I bought consists of a magnet on a pointer. Move the thing > > around, find a nail, stud found! > > Unfortunately if someone like me nailed up the drywall, you may have just > found one edge of said stud. Fortunately I don't build houses for a > living. I prefer the cpacitive/inductive/whatever type that finds the > edges and the middle of the stud. > > Dale > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body

Sorry, but the package said "Stud Finder". If you have nails, you usually have studs. If in doubt, just tap it with a hammer and you can find the center of the stud just by echolocation. Use your ears. Jim wrote: {Quote hidden}> > You bought a 'nail finder'. > > The question now is - how dead-on was the nail > to the stud? > > Jim > > ----- Original Message ----- > From: "Larry Williams" <EraseMEwizzzardspamspamBeGoneBELLSOUTH.NET> > To: <RemoveMEPICLISTKILLspamMITVMA.MIT.EDU> > Sent: Monday, February 18, 2002 8:49 PM > Subject: Re: [OT]: How does a wall "Stud Finder" work? > > > The one I bought consists of a magnet on a pointer. Move the thing > > around, find a nail, stud found! > > > > David Koski wrote: > > > > > > I can see how that would work for a steel stud. But wood? > > > > > > David > > > > > > On Mon, 18 Feb 2002 21:38:49 +0200 > > > Tal Bejerano - AMC <kooterSTOPspamspam_OUTZAHAV.NET.IL> wrote: > > > > > > > yeah coil and a very sensitive circuit.. > > > > this is the right and the only way > > > > > > > > Tal > > > > > > > > {Original Message removed}

"Use your ears." Hey! I've been using that technique for years - and on roofs too, to find the supporting 2 x 6 sloping members for putting up roof-mounted antenna tipods and guy-wire anchors. You would be surprised how ACCURATE tapping with a hammer can be! On much of this you are preaching to the choir - and it's still a 'nail finder' no matter the manufacturers labeling (perhaps they should be compelled to the 'truth in labelling laws!). You also realize that there are a lot of us on the PIC list that are after the truth, the whole truth and nothing but the truth (on some days) - so don't let our pointed addresses get too deeply under your skin. Stay light(hearted). Jim PS. I (this is just *me* now) wouldn't call it "echo location", but rather, I look for a change in 'tonal quality' from tapping wood (when doing a roof anyway) with no support behind it to wood with a 2 x 6 behind it. Again, that's just *me*. ----- Original Message ----- From: "Larry Williams" <spamBeGonewizzzardSTOPspamEraseMEBELLSOUTH.NET> To: <KILLspamPICLISTspamBeGoneMITVMA.MIT.EDU> Sent: Monday, February 18, 2002 11:27 PM Subject: Re: [OT]: How does a wall "Stud Finder" work? {Quote hidden}> Sorry, but the package said "Stud Finder". If you have nails, you > usually have studs. If in doubt, just tap it with a hammer and you can > find the center of the stud just by echolocation. Use your ears. > > Jim wrote: > > > > You bought a 'nail finder'. > > > > The question now is - how dead-on was the nail > > to the stud? > > > > Jim > > > > ----- Original Message ----- > > From: "Larry Williams" <EraseMEwizzzardEraseMEBELLSOUTH.NET> > > To: <@spam@PICLIST@spam@spam_OUTMITVMA.MIT.EDU> > > Sent: Monday, February 18, 2002 8:49 PM > > Subject: Re: [OT]: How does a wall "Stud Finder" work? > > > > > The one I bought consists of a magnet on a pointer. Move the thing > > > around, find a nail, stud found! > > > > > > David Koski wrote: > > > > > > > > I can see how that would work for a steel stud. But wood? > > > > > > > > David > > > > > > > > On Mon, 18 Feb 2002 21:38:49 +0200 > > > > Tal Bejerano - AMC <spamBeGonekooterKILLspamZAHAV.NET.IL> wrote: > > > > > > > > > yeah coil and a very sensitive circuit.. > > > > > this is the right and the only way > > > > > > > > > > Tal > > > > > > > > > > {Original Message removed}

>The one I bought consists of a magnet on a pointer. Move the thing >around, find a nail, stud found! ;-). This is the new version used since the knuckle-knocking method was obsoleted <g> Also never use a tool handle for knocking to find the heavier sound of the stud ... it's 'inappropriate'. You have to use proper certified electronic tools. Grid dip meters can be used to find hollows, pipes and also metal in walls. The exposed coil is sensitive to both E and H perturbations. I did this and it works fine. Peter -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email TakeThisOuTlistserv.....TakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body