I need help with the installation of my strain gage, is there a more simple way? And should i measure the resistance of the strain gage? Thr data sheet doesn't mention it. And for the in-amp or op-amp circuit accompanying the wheatstone bridge, do you have any advice on that? Thanks in advance :)
can we use FSR 400 instead of the strain gauge used in this video? I need to do this project for school and it is quite urgent. And if you can use FSR 400 will the installation be the same and will the results and experiment be the same? Thanks!!!
i wish i had watched your video yesterday, i just made a complete glue mess. My Datasheet told me to use epoxy so i used two component epoxy glue wich needs 12 hours to dry. Will loctite be just as durable? How do i know wich glue to use anyway? Thanks for your video
The glue I used in the video was recommended by Omega, the strain gauge manufacturer. Here's more information on their adhesives that you can compare against the epoxy you have: www.omega.com/pptst/Strain_Gage_Adhesives.html
We used a commercial strain gauge amplifier rather than a custom-built op-amp circuit. I'm not aware of any simpler installation techniques for bondable strain gauges, but some manufacturers do offer strain gauges that are pre-mounted on a cantilever beam that can be bolted to your device. You're correct that the strain applied to the gauge is proportional to its change in resistance. For more information, do a Google search for "Practical Strain Gage Measurements" by Omega, Inc.
He bought all his stuff from Omega Engr. which would be HBM gages. The only problem with Omega tho is that their technical support is pretty weak, so you need to know what you need. But I would recommend the Measurements Group of Vishay. Not only do they sell everything you need, they also have three full-time engineers who support everything they sell. The main site is also loaded with all sorts of technical bulletins for general purpose and advanced uses of strain gages. And if it gets really exotic, a support engineer will provide you with a detailed instruction.... like the time I asked them how to gage a fresh, stripped down human leg bone, still dripping with ligaments and formaldehyde!
if you buy strain gauges (aka pressure/force sensor resistors), I recommend you buy them on ebay. I bought the cheap bf350 strain gauge which is like $1.20 with shipping from china as well as the fsr402 strain gauge which is like $11. The reason the fsr402 is more expensive is that it is a more complex and more modern version. It is called a "thin film" strain gauge and does not need any special surface prep or gluing like you see for the "old school" foil type strain gauge you see in this video. It is a little larger than the cheap bf350 foil type gauge (like in video) but it is more reliable and even has a peel and stick backing so you just stick it and are done. I'm curious to test them both. I'm wondering how to use a strain gauge if you aren't dealing with metal - how do you use it on a rubber or composite material surface!? The fact that the way you glue it to the surface is so critical to its performance is a big redflag. I just assume go with a gauge who could just be taped onto the surface and "just work" like the fsr402 thin film style gauge does... (btw checkout my channel I'm building a humanoid robot that is gonna ROCK win darpa challenge maybe woot! :)
Most companies that want you to laying a gage for them will not want you to use a cheap knock off brand gages on there article. You get what you pay for and the purpose of strain gages is data. So if you data is questionable then you installation is not recommended.
Hmmmmm....... So many bad techniques, it's hard to know where to start, so, I'll start with the major flaws. Of everything I saw, "scribing the layout" was the worst. You're talking about putting a scratch in the very area that you're measuring surface strain! The layout should be burnished with a lead pencil, then scrubbed off with a Q-tip and alcohol. As to the "Super Glue", that was another mistake. Gage glue is also a cyanoacrylate, the difference being that it has been strained thru cheese cloth to take out all the "inclusions", or those tiny chunks of hard glue that gets mixed in with rest. A bump like that under a gage will throw off your sensitivity calibration. Third, now, don't get me wrong.... Surface prep can be done a lot of different ways, but the point is to a.) Remove all oily residue b.) Abrade the surface and c.) Clean it, in that order. First thing he did was to abrade any surface oil right into the surface he's trying to adhere to. And if that part came out of the machine shop, it's covered in machine oil. And then there was the whole layout mess he had going, with glue going everywhere. All he had to do was put the gages on tape first, terminals and all, and the tape protects the top of the gage and pads from the glue. And I wonder if he knows that they make a single unit gage that aligns two gages exactly like what he's trying (and failing) to do, which eliminates any issues with the gages being misaligned to each other. Argggghhhh!!!! I just saw him say to "use a scraper" to remove the excess glue from the leads. One slip and he'll gouge or scratch the surface, particularly on aluminum. ...... and OMG! He knows nothing about soldering gages!!! His main mistake was not putting a strain relief loop in the leads (can be done quickly by sliding a dental pick under the leads and then press down on both sides with tweezers). Without that, the leads can actually impart an added strain to the gage. And he didn't even mention the soldering iron temperature, which needs to be cranked up to about 550-600F with a 450F solder so as to make that connection in one second, instead of lowering the heat, leaving it on longer and frying the gage (the foil is one mil thick). And besides the ugly installation, my calibrated eyeball says the gages are neither centered side-to-side, nor are they inline to the central axis of the part. He could possibly experience "edge effects" and could be measuring strain at some small angle off the centerline instead of the principal axis. Bottom Line: I mentioned the major problems with this video, but there were a lot of details that were either left out, or he was just flat wrong about. Here's a general guide to good installation techniques. It is overly conservative, but if you go by this procedure, you will never lose a gage......... www.vishaypg.com/docs/11127/11127B127.pdf
Detroit or Aerospace??? I thought "WOW!!!" too and before I knew it, I was writing a book on the subject...... had to edit it back to about half a page....... and you just know this guy is a PHD! lol
Sir, the glue loctite 496 is not available in our country so shall we use loctite 415 instead. Expecting your reply.
I need help with the installation of my strain gage, is there a more simple way? And should i measure the resistance of the strain gage? Thr data sheet doesn't mention it.
And for the in-amp or op-amp circuit accompanying the wheatstone bridge, do you have any advice on that? Thanks in advance :)
Would this adhesive work properly if the gauges were applied to composite materials?
Thanks for the tutorial. What kind of polyurethane varnish did you use at 18:25? Is that just clear nail polish? Thanks.
Could you inform what tape you are using with Loctite 496?
can we use FSR 400 instead of the strain gauge used in this video? I need to do this project for school and it is quite urgent. And if you can use FSR 400 will the installation be the same and will the results and experiment be the same? Thanks!!!
i wish i had watched your video yesterday, i just made a complete glue mess. My Datasheet told me to use epoxy so i used two component epoxy glue wich needs 12 hours to dry. Will loctite be just as durable? How do i know wich glue to use anyway? Thanks for your video
The glue I used in the video was recommended by Omega, the strain gauge manufacturer. Here's more information on their adhesives that you can compare against the epoxy you have:
www.omega.com/pptst/Strain_Gage_Adhesives.html
nice tutorial !
I am looking for a video, installation of strain gauges on model piles to be tested in large scale shear box/tank. Suggestions please.
I'm currently doing such a project
Will a sand blast works
many thanks for your effort & this great video.
what are the parts in making a digital weighing scale? i really need it..
We used a commercial strain gauge amplifier rather than a custom-built op-amp circuit. I'm not aware of any simpler installation techniques for bondable strain gauges, but some manufacturers do offer strain gauges that are pre-mounted on a cantilever beam that can be bolted to your device.
You're correct that the strain applied to the gauge is proportional to its change in resistance. For more information, do a Google search for "Practical Strain Gage Measurements" by Omega, Inc.
This was very very helpful!!!
Where can I buy this strain gauge and accessories?
He bought all his stuff from Omega Engr. which would be HBM gages. The only problem with Omega tho is that their technical support is pretty weak, so you need to know what you need. But I would recommend the Measurements Group of Vishay. Not only do they sell everything you need, they also have three full-time engineers who support everything they sell. The main site is also loaded with all sorts of technical bulletins for general purpose and advanced uses of strain gages. And if it gets really exotic, a support engineer will provide you with a detailed instruction.... like the time I asked them how to gage a fresh, stripped down human leg bone, still dripping with ligaments and formaldehyde!
if you buy strain gauges (aka pressure/force sensor resistors), I recommend you buy them on ebay. I bought the cheap bf350 strain gauge which is like $1.20 with shipping from china as well as the fsr402 strain gauge which is like $11. The reason the fsr402 is more expensive is that it is a more complex and more modern version. It is called a "thin film" strain gauge and does not need any special surface prep or gluing like you see for the "old school" foil type strain gauge you see in this video. It is a little larger than the cheap bf350 foil type gauge (like in video) but it is more reliable and even has a peel and stick backing so you just stick it and are done. I'm curious to test them both. I'm wondering how to use a strain gauge if you aren't dealing with metal - how do you use it on a rubber or composite material surface!? The fact that the way you glue it to the surface is so critical to its performance is a big redflag. I just assume go with a gauge who could just be taped onto the surface and "just work" like the fsr402 thin film style gauge does... (btw checkout my channel I'm building a humanoid robot that is gonna ROCK win darpa challenge maybe woot! :)
Most companies that want you to laying a gage for them will not want you to use a cheap knock off brand gages on there article. You get what you pay for and the purpose of strain gages is data. So if you data is questionable then you installation is not recommended.
Missing steps on surface preparations, please check HBM /Vishay pages. :)
Thanks a lot,,it helped me very much
Please can you tell me what kind of strain gage and pads you are using
Ghiyath Nabolsi Here are the links:
www.omega.com/pptst/SGD_LINEAR1-AXIS.html
www.omega.com/pptst/BRIDGE_COMPLETION_RESISTORS_RES.html
How can strain gauge be pasted for application at 150 deg c
very interesting, sir! thanks!
Thanks for the great video
Should have used Surfactant. The water rinse and followed by solvents
awesome video, thanks!
great video
many thanks!
يوجد لدي الطريقة بلعربي
Thank you
Very rough way to install gages! Can't use super glue. There are special chemicals for those gages.
Hmmmmm....... So many bad techniques, it's hard to know where to start, so, I'll start with the major flaws. Of everything I saw, "scribing the layout" was the worst. You're talking about putting a scratch in the very area that you're measuring surface strain! The layout should be burnished with a lead pencil, then scrubbed off with a Q-tip and alcohol. As to the "Super Glue", that was another mistake. Gage glue is also a cyanoacrylate, the difference being that it has been strained thru cheese cloth to take out all the "inclusions", or those tiny chunks of hard glue that gets mixed in with rest. A bump like that under a gage will throw off your sensitivity calibration. Third, now, don't get me wrong.... Surface prep can be done a lot of different ways, but the point is to a.) Remove all oily residue b.) Abrade the surface and c.) Clean it, in that order. First thing he did was to abrade any surface oil right into the surface he's trying to adhere to. And if that part came out of the machine shop, it's covered in machine oil. And then there was the whole layout mess he had going, with glue going everywhere. All he had to do was put the gages on tape first, terminals and all, and the tape protects the top of the gage and pads from the glue. And I wonder if he knows that they make a single unit gage that aligns two gages exactly like what he's trying (and failing) to do, which eliminates any issues with the gages being misaligned to each other. Argggghhhh!!!! I just saw him say to "use a scraper" to remove the excess glue from the leads. One slip and he'll gouge or scratch the surface, particularly on aluminum. ...... and OMG! He knows nothing about soldering gages!!! His main mistake was not putting a strain relief loop in the leads (can be done quickly by sliding a dental pick under the leads and then press down on both sides with tweezers). Without that, the leads can actually impart an added strain to the gage. And he didn't even mention the soldering iron temperature, which needs to be cranked up to about 550-600F with a 450F solder so as to make that connection in one second, instead of lowering the heat, leaving it on longer and frying the gage (the foil is one mil thick). And besides the ugly installation, my calibrated eyeball says the gages are neither centered side-to-side, nor are they inline to the central axis of the part. He could possibly experience "edge effects" and could be measuring strain at some small angle off the centerline instead of the principal axis.
Bottom Line: I mentioned the major problems with this video, but there were a lot of details that were either left out, or he was just flat wrong about. Here's a general guide to good installation techniques. It is overly conservative, but if you go by this procedure, you will never lose a gage.........
www.vishaypg.com/docs/11127/11127B127.pdf
too much time wasted, just to make things unfinished, half the time that would effectively than good.
Wow !!! 1)not the way to install gages effectively. 2) see first Wow!!!!
Detroit or Aerospace??? I thought "WOW!!!" too and before I knew it, I was writing a book on the subject...... had to edit it back to about half a page....... and you just know this guy is a PHD! lol
You wasted 20 minutes of my life.
Please remove this video, this is not the proper way to prep and install strain gages.