BOSCH GMS 120 Wall Scanner

1. Introduction

The Bosch GMS 120 Wall Scanner is a professional-grade digital multi-scanner designed for reliable and precise detection of various materials behind walls, floors, and ceilings. This versatile tool helps you locate wood studs, metal objects (ferrous and non-ferrous), and live electrical wiring, ensuring safer drilling and renovation projects.

Figure 1: Front view of the BOSCH GMS 120 Wall Scanner.

Key Features

• Multi-Mode Detection: Detects wood studs, metal objects, and live wiring.
• Illuminated Ring: Provides clear detection status with green (no object), orange (object near), and red (object found) indicators.
• Automatic Center Finder: Pinpoints the exact center of detected objects for precise marking.
• Illuminated Graphical Display: Bright LCD screen indicates mode, detection strength, and battery status.
• Audible Detection Signal: An optional audible alert for detected objects, which can be turned on or off.
• Ergonomic Design: Features a soft-grip for comfortable and secure handling.

2. Setup

Battery Installation

The BOSCH GMS 120 Wall Scanner requires one 9V battery (included). To install or replace the battery:

1. Locate the battery compartment on the back of the device.
2. Open the battery compartment cover.
3. Insert a fresh 9V battery, ensuring the polarity (+/-) matches the indicators inside the compartment.
4. Close the battery compartment cover securely.

Figure 2: The battery compartment is located on the back of the device.

3. Operating Instructions

General Operation

To begin scanning, press the red power button to turn on the device. The scanner will automatically calibrate when placed flat against the surface. The illuminated ring and graphical display provide real-time feedback on detection status and strength.

Figure 3: The illuminated ring and graphical display provide visual cues during scanning.

Detection Modes

The GMS 120 offers three distinct detection modes, selectable via dedicated buttons:

• Wood Detection Mode

  Select this mode (icon resembling wood) to locate wood studs behind drywall. The device will indicate the presence and center of wood elements.

  Play video

  Video 1: Demonstrates the BOSCH GMS120 Wall Scanner in action for wood detection.

  

  Figure 4: The scanner indicating a detected wood stud.

• Metal Detection Mode

  Choose this mode (icon resembling an anvil) to find magnetic and non-magnetic metals, including rebar, metal studs, and copper pipes. The GMS 120 offers deep metal detection for steel up to 4-3/4 inches (120 mm) deep in cured concrete.

  

  Figure 5: Detecting metal objects like rebar within concrete.

• Live Wiring Detection Mode

  Activate this mode (icon resembling a lightning bolt) to detect live electrical wiring. This is crucial for avoiding hazards when drilling or cutting into walls. The scanner can detect live wiring up to 2 inches deep.

  Play video

  Video 2: Overview of the BOSCH GMS 120 Wall Scanner's capabilities, including live wiring detection.

Automatic Center Finder

The GMS 120 features an automatic center finder that precisely locates the center of detected wood or metal objects. When the device is centered over an object, the illuminated ring will turn red, and the display will show a 'CENTER' indicator. A small hole at the top of the scanner allows for easy marking of the detected center with a pencil.

Figure 6: The scanner indicating the center of a detected object.

4. Maintenance

• Cleaning: Wipe the device with a soft, damp cloth. Do not use abrasive cleaners or solvents.
• Storage: Store the scanner in its carrying pouch in a dry, dust-free environment when not in use. Remove the battery if storing for extended periods to prevent leakage.
• Avoid Extreme Conditions: Do not expose the device to extreme temperatures, direct sunlight, or high humidity.

5. Troubleshooting

6. Specifications

7. Warranty and Support

The Bosch GMS 120 Wall Scanner comes with a two-year warranty. For full terms and conditions, please refer to the official warranty documentation or visit the Bosch Power Tool Warranty website. Register your tool within eight (8) weeks of purchase for a total of two (2) years coverage.

Figure 7: Bosch Limited Warranty details.

For additional support, troubleshooting, or to access the complete user manual, please visit the official Bosch website or contact Bosch customer service. You can also find the User Manual (PDF) here.

Bosch measuring tools are known for their precision, ease of use, and robustness, ensuring accurate results in various construction and home improvement applications.