Extech MO55A Combination Pin/Pinless Moisture Meter
- Fast, Accurate Moisture Detection - Without the Guesswork
The Extech MO55A Moisture Meter is a versatile, dual-function tool designed for professionals who need quick, reliable moisture readings across a wide range of materials. Combining both pin-type and non-invasive pinless technology, this device allows you to measure moisture your way — whether you’re probing surfaces directly or scanning beneath them without causing damage.
Perfect for building inspections, restoration work, and maintenance tasks, the MO55A helps you locate hidden moisture issues before they become costly problems.
Key Benefits
✓ Dual Measurement Technology
Switch seamlessly between pin mode for precise contact readings and pinless mode for non-destructive scanning beneath surfaces. Ideal for checking walls, flooring, ceilings, and more.
✓ Non-Invasive Scanning up to 25mm
Detect moisture below the surface without leaving marks — perfect for finished materials where damage must be avoided.
✓ Clear, Easy-to-Read Display
A bright, colour LCD screen with backlight ensures readings are visible in low-light or challenging environments.
✓ Instant Audible Feedback
An integrated alarm increases in frequency as moisture levels rise, allowing you to quickly identify problem areas without constantly checking the display.
✓ Designed for Real-World Applications
Suitable for wood, drywall, plaster, concrete, and other building materials, making it a go-to tool for contractors, surveyors, and property professionals.
Ideal For
- Building and property inspections
- Damp and moisture detection
- Water damage assessment
- Flooring and subfloor checks
- Leak investigation behind walls and ceilings
- Restoration and remediation projects
Extech MO55A Key Features:
- Combination pin and pinless moisture measurement
- Measures moisture in wood and common building materials
- wood and common building materials, including wallboard, sheetrock, cardboard, plaster, concrete, and mortar
- Non-destructive scanning depth up to 25mm
- Visual indicators with intuitive icons for quick interpretation
- Audible alert system with increasing beep frequency corresponding to higher moisture levels
- Compact, handheld design for easy use on-site
- Equipped with a high-contrast color LCD featuring backlight for clear visibility in all lighting conditions
- Supplied with 2 installed pins, 2 spare pins, a protective cap, and batteries
Technical Overview
| Features | |
| Measurement Method | Resistance (pin) & electromagnetic (pinless) |
| Moisture Range (Wood) | 5% to 50% (pin mode) |
| Moisture Range (Building Materials) | 1.5% to 33% (pin mode) |
| Relative Moisture (Pinless) | 0 to 99.9% |
| Resolution | 0.1% |
| Display | Backlit colour LCD |
| Power Supply | 3 x AAA batteries |
| Auto Power Off | ✓ Yes (approx. 3 minutes) |
| Operating Temperature | 5°C to 45°C |
| Weight | Approx. 151g (excluding batteries) |
What comes with the Extech MO55A?
- Extech MO55A Moisture Meter
- Protective cap
- 3 x AAA batteries
- Spare replacement pins
- Quick start guide
Why Choose the Extech MO55A?
When moisture detection matters, you need a tool that delivers both accuracy and flexibility. The MO55A gives you the confidence to assess materials quickly, detect hidden issues, and make informed decisions on-site — all with one compact device.
❓ Frequently Asked Questions (FAQ)
Q: What is the difference between pin and pinless moisture measurement?
A. Pin mode uses small probes inserted into the material for highly accurate, localised readings, while pinless mode scans beneath the surface without causing any damage — ideal for finished materials.
Q: What materials can the Extech MO55A measure?
A. It’s suitable for wood and common building materials, including wallboard, sheetrock, cardboard, plaster, concrete, and mortar
Q: How deep can the pinless mode detect moisture?
A. The pinless sensor can measure moisture below the surface to a depth of up to 25mm.
Q: Is this moisture meter suitable for detecting damp behind walls or floors?
A. Yes, the pinless function is especially useful for identifying hidden moisture behind walls, under flooring, or beneath tiles without needing to drill or probe.
Q: Does the device require calibration?
A. The meter automatically calibrates in pinless mode when used in open air, making it quick and easy to start using.
Q: Is the MO55A easy to use for beginners?
A. Yes, it features a simple interface with clear icons and an audible alert, making it suitable for both professionals and DIY users.