Bosch GMS120 Review

Author: Reece Thompson | Updated on March 6, 2021
The Bosch GMS 120 is the market leader in the stud detector space. It's a handy tool that gives you “x-ray vision” to know what is behind a wall.
Are you considering buying the Bosch GMS120? 

Doing DIY work is something that a lot of homeowners do or want to do at some point. It’s a great way to personalise your space, make it your own, and put your mark on it. But doing your work can be very satisfying. This is where wall scanners come into the picture.

I cannot tell you how many health and safety issues I have evaded over the years by having a great scanner at hand.

To do this, you will need to have the right tools. Locating studs in your walls can make all the difference between a job well done and a total disaster.

What Makes Bosch GMS120 a Professional Multiscanner?

A lot of scanners have limitations as to what they can scan. On the other hand, professional scanners can pick up a lot of things that are behind walls and help avoid a catastrophe as you work.

This scanner has multimode scanning capabilities, making it a more professional digital scanner than others in the market. It has three scanning modes for you to choose from.

Some of the features that make it a professional scanner are detecting copper wiring at a maximum depth of 2 inches. It can detect steel at a maximum depth of 4-3/4 inches, and it can also detect copper at a maximum depth of 3 1/8inches and studs up to a maximum depth of 1 1/2inches. Also, this scanner doesn’t just work for walls, but for floors as well.
bosch scanner lights up green on the wall

Positives of This Model

  • It is a multi-purpose scanner.
  • It is versatile
  • It can be used by electricians, contractors, plumbers, and so much more.
  • It is durable and delivers consistently.
  • It also works on floors.
  • It has an informative graphic display.
  • It is user friendly

... and the Negatives?

  • It is on the higher end of the pricing scale.
  • The ring light may come off as brighter than the LCD screen, making it harder to read in low light situations
scanner picking up a copper pipe behind the stud wall

How do I Use it?

The Bosch GMS 120, has three modes to help you detect and scan a wall and even a floor. It is easy to use. So even if you're a first-timer, it won't take you long to get the hang of it. 

To use it, simply turn on the power button. Unlike other scanners, you don’t need to calibrate it. It also has a centre finder. When you turn it on, it self calibrates and then you have to choose the model that you want it to work in.

Of the three modes, there is one to detect studs, plumbing, and live wires. It is one of the few scanners on the market that differentiates the objects that are detected behind the wall. All the information that it gathers gets displayed on the LCD screen, which is quite extensive in how it is displayed. The ring light tells when you are close to an object and also when you are not.

As you scan across the wall, the scanner gets more sensitive. Some users have found this to mean that it gives inconsistent readings, but it is getting more acquainted with the wall and more accurate. It also has an audio option, which beeps as you scan over objects. The centre indicator will tell you when you have hit the centre of an item.

Does the Bosch GMS120 Find Other Materials?

This is a multi-purpose scanner and will find different types of materials. This is one of the reasons why it is sought after and often labelled as a professional tool. 

It will detect both magnetic and non-magnetic metals and power cables. It will also scan other objects that you don’t want to be drilling through or damaging in your quest to make home improvements.

What type of material does Bosch GMS120 find?

The list of materials that the Bosch GMS120 can find is quite varied. As such, it is a handy gadget to have when you are looking to make any holes in the wall, drill into it, or make any type of renovations. It has special deep metal detection.

While other scanners may just scratch the surface, this one goes in for the kill and detects objects deep behind the wall. This digital scanner can detect several objects, and these include:

  • Metal objects
  • Wooden objects
  • Electrical cables and live wiring
  • Pipes
  • Rebar
  • Studs
  • Copper wiring
  • Copper
  • Magnetic metals
  • Non-magnetic metals
buttons on a device

Can This Scanner Work in Adverse Lighting Conditions?

One of the great features that you will find on this scanner is the digital display. It is quite detailed and as such will give you more information about what you are scanning. It will show you detection mode, the strength, and more information to help you better understand the situation behind the wall. Whilst this is all well and good, it could go south if this display weren’t backlit.

The screen is backlit, making it easy to read even at night or in low light. The detection ring also helps let you know how near or far you are from an object. It flashes green if there is no object, orange if you are close to an object, or red if it is in the detector's range.

Final Thoughts

We all know that there is so much behind walls that are not visible to the naked eye. As such, if you intend to build or drill into the walls, then it is prudent to know what lies beyond.

You don’t want to hit electric wires or studs. The Bosch GMS 120, is an efficient digital multi scanner, that may make your renovation job easier.

To read our review on the overall aspects of other brands, read our review of stud finders.
"You really need to practise using it for a while to understand how it works. That's not a criticism of the tool, just the reality of what this gives you over the cheaper simple metal detectors"