The New Bosch GMS120 Wall Scanner features Multi-Mode Detection - For wood studs, metal objects (rebar, studs and steel/copper pipes) and live wiring. Illuminated Graphical LCD Display - Indicates mode, detection strength, and more. Deep Metal Detection Capability - Detects steel up to 4-3/4-in (120 mm) deep in cured concrete. Automatic Center Finder - For locating center of detected wood or metal object. 3 Selection Modes (Wood, Metal, AC Wiring) with automatic calibration for easy and precise detection. Audible Detection Signal - With On/Off button. Ergonomic Soft-Grip - For secure grip and comfort. Illuminated ring indicates detection status.
(41 reviews) 41
75%of customersrecommend this product30 of 40reviews
Rating Breakdown41 reviews
75%of customersrecommend this product30 of 40reviews
I was frustrated buying cheap, throw-away stud finders that never seem to work when you need one, so I stepped up to the Bosch GMS120 Professional Wall Scanner. It comes with a nice flexible storage case with hand lanyard and belt loop. Using this wall scanner is not intuitive and requires reading the instructions thoroughly. There are multi-colored flashing lights, changing bar graphs, symbols and sounds that requires prior working knowledge to use properly. The instruction pamphlet would benefit from better graphics and illustrations.
The scanner has three modes; wood, metal or live electrical. In the wood mode it actually scans for all three, and will display the various signals and graphs on the display. It also identifies the center point of wood studs or metal objects. Selecting metal mode excludes wood and scans for only ferrous/non ferrous metals and “live” electrical wires. It is important to note that the scanner detects wires where current is flowing. The warning light may not flash for wires that have no current draw.
The Bosch GMS120 performed very well in all three modes during my testing and use. As recommended in the instructions, I used a thin piece of cardboard over the uneven ceiling texture, and it detected the joists perfectly. Now I don’t have to drill and patch holes in the ceiling when looking for the joists. The scanner could be more user friendly with better graphics in the display, but it’s still a giant leap above the cheap stud finders.
Used the same day I received, easy to use and it worked great. Found the studs quickly, no wires or pipes in the area I was mounting a grab bar in the bathroom. I own a number of BOSCH products, I've never been disappointed.
As much as i like Bosch products, their wall scanners are not accurate at all. My new $20 scanner scans better than this one. Thanx to Bosch scanner i put a nail into the BX (electrical wire in the wall) under the electrical box that was covered by a painting :-( The Bosch scanner didn't show any electrical in this area and it was a regular sheetrock wall... Ended up returning the unit and paying a huge repair bill... Stay Away from this scanner....
This stud finder really sounds like it does it all: find studs, live wires, and metal in the wall. However, I was very disappointed that it didn't perform better for the price. My $15 stud finder outperformed it on several of the walls that I tested it out on, which is inexcusable in my book.
Initial impressions: - The stud finder is a little bit larger than most I've used in the past. - Bosch packed a lot of features into this, including a 3-color led indicator, a signal strength display, a backlit display, the option to turn sound indications on/off, and the option to turn the backlight on/off. - The through-hole for marking stud locations is a pretty cool feature too.
Wood stud detection: - The main application I planned on using this for was locating studs. I started over an electrical outlet, since I knew there should be a stud on one side of it. I used both stud finders (my old one and this one) simultaneously, and my old one lit up reliably every 16", turning on and off for each side of the stud. The Bosch gave me intermittent indications, some of which were right in the middle of the 16" spans. The centering feature is OK, but requires that you backtrack once you reach the far side of the stud. Even then, it usually gives about a 3/4" range that it calls the "center."
Metal detection: - The best-performing feature is the metal detecting capability. This is the only reason I'm giving it more than one star. I do a bit of woodworking, and missing a nail before I send a board through my planer can cost me $50-60 on a set of knives. So if I find two nails, the scanner has paid for itself. I tried it out by holding a screw on the far side of an 8/4 walnut board, and the scanner gave a strong indication when I passed over the screw's location. It couldn't find a staple through the board though, but it can detect a sewing needle from about 1/4" to 1/2" from the scanner, without anything in between. - If you want a more reliable stud finding method, I'd use the wood detection capability in conjunction with the metal detection feature. Find the general location of the stud with the wood detection, then use the metal detector to scan up and down to find the screws.
Live wire detection: - This thing is garbage when it comes to finding live wires in your walls. I can scan all around electrical outlets and light switches without so much as a peep from it. My old $15 stud finder lights up like crazy when I scan the same areas. I even scanned the extension cord powering an overhead light in my garage, and the Bosch scanner couldn't pick it up even when I touched them together! I had to rub the wire all over the scanner until it lit up. I would definitely NOT trust this thing to find a live wire before I drilled into the wall.
Conclusions: - Unless you are buying this in part for the metal detection capabilities, go with a different scanner. Even then, you may still be able to find a separate stud finder and metal detector for about the same total price.
Pros: metal detection works
Cons: Difficult to Use, poor performance, low accuracy, expensive
I had just remodeled my bathroom so I knew where all the studs and electrical was located. It worked great to find the studs. The display showed where the center was clearly. It even has a hole to mark on the wall.
But I tried the electrical setting and it found the live wires sometimes and sometimes not. I even tried it over exposed wires and it didn't sound off.
Overall, it worked great for wood, not so great for electrical. I didn't have an occasion to try it on steel setting.
With the Bosch GMS120 digital wall scanner I was able to locate 'buried' Romex in our rastra block walls as well as the wooden blocking embedded for cabinet installs. Followed the instructions and had no problems using this tool.
Pros: Easy to Use, All In One, Accurate, Good Size & Weight
If you are after something to locate studs for hanging a picture or mounting a TV, then this detector is overkill. But if you are a serious modeler, or need a full featured detector, this is the tool for you.
I should warn you that there is leaning curve if you want to make full use of this detector. It presents a lot more information then a standard stud detector. There is the audio output like a basic stud detector. I find it annoying, but you may find it useful. It would be nice if it had a volume control, but at least you can turn it off. And the detector remembers for the next time you use it. It has a detector. It has a centering hole, with a ring around it that changes color to give a quick visual indication. Then there are two bar graphs that show "signal" strength, and centering.
The centering graph is easy to use, but it needs to calibrate itself, so it is not going to show you the center of the stud until you hit the far edge. This is because it does not know how wide the stud is before then. But once it knows, you can back up the scanner and get a good center reading. Once you get used to it, you will love it because it gives you the true center. It works the same for other detection modes.
The strength meter will give you an indication of how deep something is in the wall. Once you get a feel for it, it will let you estimate how deep or how big a metal object is. It is handy for telling the difference between a nail and a buried cable or pipe.
The icons will tell you when it is detecting something for a different mode then you are using. If you pay attention, it can save you from cutting a wire.
The mode button you select lights up to remind you what mode you are in, and there is a light you can turn on to illuminate the LCD display. Someone was thinking when they designed the scanner.
I was able to try it on both plastered and drywalled walls. I was luck to have 2 walls where I know the location of the studs, so I could test how accurate the detector is. For the drywalled walls, it was very accurate. For plaster walls, the results were not as good. From past experience, I was surprised that it could detect the studs at all. It did much better when set to detect the nails fastening the lath to the studs.
How well the live wire detector works depends on the wiring. If it detects the wire, it will give you a nice map of how it runs. But if you have BX, or knob and tube wiring, it may not detect the wiring. The metal sheathing on the BX effectively blocks the signal from the live wires. With knob and tube wiring, it will usually detect the wires to a switch if the switch is off, and their is a light in the circuit. If the switch is on, it may miss the wires. All non-contact detectors run into the same problem. Luckily it is rare to run into knob and tube wiring. I just happen to have a house that is over 100 years old, and has several different types of wiring. So it presents interesting challenges that you don't normally run into!
Pros: All In One, Accurate, Good Size & Weight, Long-Lasting
I was hoping to detect joists behind a plaster ceiling. The plaster thickness variation resulted in false detections. I ended up drilling small holes in the ceiling to find the joist. The other features for metal detection and live wire detection worked OK.
I have a drawer full of these devices, ranging from $15.00 - $40.00. I am a third generation Architectural wood worker /consultant. I am the first generation to have a device bigger than a magnet to locate studs in a wall. In the quest to get a stud finder that is accurate, I have recently ordered this companies $1000.00 radar model, this one, as well as the red competitors $250 radar model (much like the $1000.00 one). I have returned all of them except the competitor’s radar model because it gave the best results. I have come to the conclusion that with all the variables one will run up against, nothing is going to give the results I require that I can’t accomplish by measure tape, nail and wall patch. Nice try by Bosch, but fail in my book. This is what I experienced after trying on several different areas. Studs would appear, and then disappear, leaving doubt. The electrical detect worked best but still not as accurate as expected. The display was only visible if I was looking straight into it and not at an angle which made it difficult to see at high, low and side angles. The LED multi colored displayed well from angles but was just a light show for me. The hole to mark with is a good idea.
This is a very good and solid wall scanner, it does what it says and is very accurate in finding studs behind drywall. It has a bunch of nice features and I prefer to use it over my cheaper Zircon stud finder.
It has a nice opening so that you can easily mark the drilling location. A simple but very convenient feature. The display, lights, and tones are all very useful especially when working in tight locations or on ladders.
I wanted to use this to locate floor joists under berber carpet in order to drive some screws to fix flloor squeeks. The manual says it can do such job. I was disappointed with its inability to detect those joists. It kept beeping like crazy and gave irregular results no matter which direction I ran. My Zircon stud finder also struggled and couldn't get this job done so I'm sure this has a lot to do with the type of carpet and thick undercarpet layer.
I also tested the feature to detect wiring in the wall, and this works well as described.
I did not test the feature of detecting rebar in concrete walls.
I cannot give it 5 stars since I was expecting a better result for undercarpet floor joist detection.
Pros: Easy to Use, All In One, Sturdy, Accurate, Strong, Good Size & Weight
I'm a home handyman and have occasional use for a stud-finder. This wall scanner looked promising, but I found it more difficult to use than my inexpensive LED stud finder.
The biggest problem is that it takes as many as 5 passes, to zero in on a stud. Even then, it can claim the center is far enough off that a nail would miss the stud. When I did a fast sweep across the wall looking for a stud, it would occasionally give no indication that a stud was passed. I tested how long it took to zero in on the center of a stud with this scanner and my old stud finder and the scanner took twice as long - 6 seconds and 5 passes compared to 3 seconds and 1 pass (which actually found the two edges of the stud, from which I could mark the center).
There are several usability problems. The LCD display is hard to read in most conditions unless the backlight is turned on. With the backlight on, I cannot read the display if my eyes are above it - I either have to hold the scanner at eye level or turn it upside down.
The audible tone is fairly loud and of an annoying pitch. I turned it off right away. It does sound to indicate when within 6" or so of a stud (yellow light territory), but then keeps sounding for the (up to) 5 passes I have to make to zero in on the stud.
Speaking of the lighted ring - it's a useful idea but I found "green" meaning "no stud" and "red" meaning "stud found" to be counter-intuitive - I wanted it the other way around. I can understand using red to mean "stop moving" but I associate red with bad things, not good.
Another problem I had were with the instructions that (1) all 3 pads on the back had to contact the wall surface (2) that the hand holding the scanner couldn't touch the wall surface and (3) that your other hand couldn't touch the wall, and (4) when scanning a wall with an uneven surface place thin cardboard on the surface and scan over the cardboard.
Most of my walls are textured. With my old LED stud finder I used my fingertips to hold the finder slightly off the wall so it didn't snag on the texture. When I did this with the Bosch scanner, it found a stud every few inches. So I got some cardboard and had better results, but then my other hand was touching the wall since I was holding the cardboard and trying to move it with the scanner. The contact pads on the back of the scanner are pretty soft and I managed to create some grooves in them trying to scan the textured wall. I ended up putting transparent tape over the pads to protect them. This didn't seem to affect the operation of the scanner.
I also tested locating live electrical wires and had no luck, even with over stud bays I know contain live wires.
It's possible that with practice and regular use this would be a good tool, but for my occasional needs I'll reach for my old stud finder first.
Pros: Durable, All In One, Sturdy, Strong, Long-Lasting
Cons: Difficult to Use
2out of2found this review helpful.
Review 12 for Digital Wall Scanner
Not impressed for general stud finding
PostedFebruary 2, 2014
No, I do not recommend this product.
I figured considering the cost and the fact it claims to find the stud centers was a great feature. However, in practice, even after reading the manual and trying different methods it still will not reliably find the stud center. You'll usually get somewhere on the stud, but I can measure 4-5 times on a stud and the "center" indicated will drift at least 1/2". On brackets that have staggered holes I've missed the stud several times since starting to use it. My $20 edge finding stud finder reliably and repeatedly finds the stud edges, do I need to mark the edges and find the center myself, yep, and sometimes that's annoying but I get much closer to the stud center with it. I don't use the fancy metal/pipe settings, I do like that it picks up electrical, but even a $20 stud sensor today does that. If you read the reviews they are very mixed, I doubt it's because all of those people didn't read the instructions. There's a youtube video from Bosch demonstrating the unit and mine reacts very differently compared t the unit on the video. The video unit starts green goes yellow then red, then once it's past the stud it goes in the reverse order very predictably. Mine starts green but never goes back to green once I go past the stud and it seems to get confused between red/yellow. It's also very hard to read the display unless it's at least eye level or higher.
Honestly it might be the stud center finding feature, I've noticed on other high dollar auto-center locating stud finders they also tend to be hit and miss on actually finding the true center, while much cheaper edge finding models are very good at finding the edges.
I do like that it has a back-lit screen and you can turn the beeping off.
I've had many, many, many stud finders that do many things. This one is just another fancy looking stud finder that can do multiple things. As for finding wood studs, it works, but its precision is not repeatable. I would follow the instructions and it would consistently find a different center on the stud. As for finding metal its good, but could be more accurate as well. I personally have been using magnets to find the screws/nails that are holding up the drywall and that is the most accurate thing i have ever used. For a bosch product, I would have expected more.
Pros: Easy to Use, Good Size & Weight, Light Weight
I moved into a condo that has concrete construction and metal framing instead of wood. This unit made it so easy to find the metal studs and avoid rebar in concrete. Installing my TV wall mount was a breeze.
Pros: Easy to Use, All In One, Accurate, Durable, Light Weight
I bought this as a Christmas present for my son-in-law to replace a stud finder he lost in a flood. Perfect timing since I needed one to locate studs and miss copper pipes in a bathtub wall when I installed some grab bars. The centerline sensing of studs is a cool feature. You just have to read the instructions and remember to horizontally scan across the area a couple of times for the electronics to establish a density pattern. In my case, I needed to miss the studs by a minimum of 1" for those very large hollow wall fasteners used for grab bars.
This instrument will detect water pipes and electrical conduit, BX and Greenfield. It will not sense Romex or similar type of wiring that is NOT live. The circuit has to be HOT and the instructions are very clear on that. A previous reviewer was complaining about that and apparently didnt read the instructions.
Given a choice of brands, I alway choose Bosch when possible because of total value...workmanship, quality, durability.
Pros: Durable, Easy to Use, All In One, Sturdy, Accurate, Strong, Good Size & Weight, Light Weight, Long-Lasting
This is much more accurate than my top of the line Zircon unit. It also warns you of live electric even if you have it in wood stud mode. As with all stud finders this works best with drywall rather than plaster/lath walls but it will locate studs and electric even in those tough situations.
First off I was kind of surprise at the size of this wall scanner. It's quite large, not something I would carry around or throw into a tool belt. It does come with a battery and a nice bag that you can put on your belt.
As for how it works, there are some good and some not as good as I would like.
Plaster walls seem to confuse any scanner, and this one is no different. About 75% of the time it finds the studs and is repeatable. But with varying plaster thicknesses it can be thrown off.
The Good: Seems pretty good as a metal detector, it finds nails, screws, rebar, most pipes, metal studs pretty well. Stubs behind drywall and picked up pretty well too. it looks impressive with the change color ring and the display. And the display is backlit too.
The not so good: Picking up electrical wire is pretty poor, unless the line is live and touching the backside of the drywall. The display and changing color ring make for a bit of a mystery as to where the edge of anything is. My simple $10 stud finder is a simple on/off light and makes marking stud edges pretty clear.
This stud finder from Bosch is a high end version of the cheap yellow ones that are ubiquitous. It includes a very nice, bright LCD display, along with a multicolored ring of lights that indicates when you're on top of your target. The audio can be disabled, and there is a back-light on the LCD display. The rubber grip on the unit is an added nice feature.
In practice, however, i wasn't really impressed. I've never had luck with stud finders, as they always seem flaky and unreliable. This one is a slight improvement, with many additional features that add to the appeal. But on the basic purpose (finding wooden studs) there doesn't seem to be much to write home about.
Application This stud finder performs best on regular drywall walls. It finds the studs, but you usually need to make 3 or 4 passes to make sure. Our house has the old plaster walls on metal lath and this, like pretty much all stud finders, doesn't like that. It is suggested to use the metal-finding mode to locate the nails holding the lath to the wall. This, surprisingly works quite well, and i was able to find studs with some consistency. The mode i had most success with was the power-finding mode. any time you went over a live wire, AC was immediately detected, and the unit would flash. This is great if you're looking to cut holes and want to avoid cutting into wiring. However, when searching for live wires inside plaster/metal lath walls, results were once again mixed. The ceiling detection performed the worst. The studs were barely detectable, and the power-line indicator was pretty much always on within a foot of any fixtures. I don't know why this is, but perhaps the unit just doesn't like to be horizontal.
Downsides There were also a number of design details that i felt took away from the usability of this device. Primarily was the inconsistency of the stud finder. It seemed very jumpy and where in one spot it was reading nothing at all, a tiny bit over it would be blaring all alarms. You really need to move this unit slowly to get accurate results. This is time consuming when you have a lot of wall to cover. The main ring in the middle also seemed excessively flashy. With constant flashed between green, red, and yellow, it became quite disorienting and distracting. The hole in the middle of the device seems like a good idea. However, it's too small for a standard carpenter's pencil! The LCD, while nice to look at, was difficult to read at angles. This is especially true when using on the ceiling. You really need to be looking at the LCD straight on.
The Feet And lastly, something that seems like a good idea, really isn't: the clear anti-scratch feet on the bottom of the device. There are three of them, one small one up top, and two longer ones on the bottom. The first problem is that the device rocks too easily. Even on perfectly flat surfaces, the slightest pressure down on one side lifts up the other side, causing misreads to occur. This is very frustrating. The bottom two feet are longer vertically, yet the primarily movement of device is horizontal. The second issue is that the feet are simply too small. The walls in my house are all textured with an orange-peel texture. This features large bumps over the entire surface of the walls. The top small foot doesn't like this at all. Any movement is extremly rough and jittery with the foot occasionally catching and throwing off the balance of the sensing head. I'm sure this is primarily why the readings were spotty and inconsistent. The feet do not cause any problems on smooth surfaces. If the device had a completely flat back, due to the unit's size, it would equalize out the rough spots, allow smoother movement, and offer more consistent readings.
Summary A nice device with many neat features. Comes with a carrying case. It generally works well, and has pretty good accuracy on plaster/metal lath walls when in metal mode. Unfortunate, inconsistent readings require far to many slow passes to determine where the stud sits. Wall textures interferes with readings due to small feet on back. Busy LCD display along with multicolored flashing lights and beeping make this a confusing device to use. Does not work well on ceilings.