I’ve often felt like studs finders are the snake oil of home improvement, and I could do just as well knocking on the drywall to find a stud. I’m sure you’ve been there too, driving a screw through sheetrock only to find there’s nothing behind it. Well Bosch is working to change all that, and today we’re taking a look at the GMS120 Wall Scanner. Although this tool came out early last year, it’s a new addition to the OPC workshop, and I’ve rigged up a test for the GMS120. Let’s see how it performs.
Our GMS120 came to us courtesy of Lowe’s, and you can find it in-stores and online for $79.98. Here’s a link to the Lowe’s site where you can see all the product details.
The GMS120 is a wall scanner that can locate wood studs, metal studs, copper pipe, PEX tubing filled with water, rebar, live wires (110-230v) and more. Plus, the wall scanner can operate over drywall, cured concrete, and plaster and lathe.
To operate the GMS120, you press the red power button and select between Wood, Metal and AC Wiring mode. The best measurements are achieved by selecting the appropriate mode. Next, you slide the tool over the surface to be scanned. The light ring, audio signal and display indicate the results, and you can mark the wall through the marking hole.
To test out the GMS120, I setup a sheet of 1/2″ drywall and anchored a 2×4 stud, live wire (extension cord) and a segment of copper pipe behind it. I cut that little window so the accuracy of the GMS120 would be easy to see.
I covered up the window while I was doing the scanning to ensure I didn’t “cheat”.
Using the GMS120 in each mode, I looked for the center of each test object and marked the results on the drywall.
In my testing the GMS120 did an excellent job locating the copper pipe and found center every time. The wall scanner also found the live wire very quickly. Unfortunately, the scatter plot made it a little difficult to pinpoint the exact location. However, I knew a live wire was nearby.
The real test of a wall scanner is how well it detects studs because that’s primarily how most users will employ the GMS120. I took a lot of readings, and the found center was actually more like the left edge. I also tried out the GMS120 in the house to detect known studs (around switch and outlet boxes), and it performed better. Ultimately, I feel like the GMS120 is more reliable than many other stud finders available.
I found it was really tough to see the display with the backlight turned on. If I wasn’t looking straight at the scanner, the display was just about invisible, and that was a bit disappointing.
Again, if you’re looking to purchase the Bosch GMS120, check out your local Lowe’s or Lowes.com.
Specifications: GMS120 Wall Scanner
- Max Detection Depth Copper Wiring: Up to 2″
- Max Detection Depth Ferrous Metals: Up to 4-3/4″
- Max Detection Depth NonFerrous Metals: Up to 3-1/8″
- Max Detection Depth Wood Substructures: Up to 1-1/2″
- Operating Temperature: 14°F / -10°C ~122°F / 50°C
- Battery: 9V
- Weight (lbs.): 0.6
- (1) – Protective Case
- (1) – Hand Strap
- (1) – 9V Battery
In case you’ve lost it, I found the manual available at that link.