Portable thickness gauges are essential tools in industries such as manufacturing, construction, aerospace, automotive, shipbuilding, and oil & gas. These devices enable fast, non-destructive measurement of material thickness, helping ensure structural integrity, corrosion monitoring, and quality control without damaging the test object.
Whether you’re checking the wall thickness of a pipe or verifying coating layers on a metal surface, selecting the right portable thickness gauge depends on understanding your application, material, and required accuracy. This guide outlines the key factors to consider when choosing the best gauge for your needs.
Define the Application
Begin by identifying what you’re measuring and the environment in which you’ll work:
- Material: Are you measuring metals, plastics, composites, or coatings?
- Surface Type: Smooth, rough, curved, painted, or corroded?
- Access: Is the surface easily accessible, or will measurements be taken in tight or hazardous areas?
- Industry Standards: Are there specific codes or calibration standards (e.g., ISO, ASTM, NACE) you must follow?
Choose the Right Measurement Method
There are two main types of portable thickness gauges:
a. Ultrasonic Thickness Gauges (UTG)
- Used to measure substrate thickness (e.g., metal walls, plastic pipes) from one side.
- Works by sending sound waves through the material and measuring the echo time.
- Ideal for measuring through coatings or corrosion without removing the surface layer (with dual-echo models).
Applications: Corrosion inspection, pipeline maintenance, tank wall thickness.
b. Coating Thickness Gauges
- Used to measure the thickness of surface coatings, such as paint, plating, anodizing, and galvanizing.
- Work based on magnetic induction (for ferrous substrates) or eddy current (for non-ferrous substrates).
Applications: Automotive refinishing, industrial coating, quality control of painted parts.
Some gauges combine both methods in dual-purpose models for maximum versatility.
Consider Key Technical Specifications
a. Measurement Range
- Select a range suitable for your application. UTGs typically measure from 0.5 mm to over 500 mm.
- Coating gauges usually measure from 0–2,000 μm (or more, depending on model).
b. Accuracy and Resolution
- Look for ±1–3% accuracy or better.
- Higher resolution (e.g., 0.001 mm or 1 μm) is useful for thin or precision applications.
c. Probe Type
- Integrated probes: More compact, suitable for general use.
- External probes: Offer flexibility for hard-to-reach or curved areas.
- Some models support interchangeable probes for different materials or ranges.
Material and Surface Compatibility
Ensure the device supports:
- Various substrate materials (e.g., steel, aluminum, plastic, fiberglass).
- Curved, rough, or coated surfaces.
- Multi-layer structures (if measuring coatings over coatings).
UTGs often require velocity adjustment or material selection presets to accommodate different substrates.
Display, Interface, and Ease of Use
- Clear digital display: Preferably with backlighting for low-light conditions.
- Graphical mode: For waveform or thickness trend visualization (useful in UTG).
- Intuitive controls: Simplifies operator training and minimizes errors.
- Menu language options: Helpful for global teams.
Data Management and Connectivity
Modern devices often include:
- Internal memory for storing thousands of readings.
- USB, Bluetooth, or Wi-Fi for transferring data to PC or mobile apps.
- On-device statistics: AVG, MIN, MAX, standard deviation, and alarms for QA monitoring.
- Support for SPC software or cloud-based reporting.
Battery Life and Ruggedness
- Minimum 8–12 hours of battery life recommended for fieldwork.
- Rechargeable Li-ion or AA batteries are common.
- Choose a model with IP-rated or rubberized casing for protection in industrial or outdoor environments.
- Some models are ATEX-certified for use in explosive environments.
Calibration and Compliance
- Look for devices with zero-point calibration, two-point calibration, or auto-calibration options.
- Ensure the device complies with industry standards like:
- ISO 2178 / ISO 2360 (coating gauges)
- ASTM E797 / EN 14127 (ultrasonic thickness)
- Request calibration certificates traceable to national standards.
Advanced Features (Optional but Useful)
- B-scan capability: Visual cross-section of thickness changes (in UTG).
- Echo-to-echo mode: Measures base metal only, ignoring paint layers.
- Live graphing: Real-time measurement trends.
- Temperature compensation: For accurate readings in varying conditions.
- Alarm thresholds: Audible or visual alerts for out-of-tolerance readings.
Popular Brands and Models
Some well-regarded manufacturers include:
- Olympus (e.g., 38DL PLUS, Magna-Mike series)
- Elcometer (e.g., Elcometer 456, MTG series)
- Defelsko (e.g., PosiTector 6000, UTG M)
- Dakota Ultrasonics
- Fischer
- TIME Group
- Phase II
Compare based on your required features, support availability, and budget.
Conclusion
Choosing the right portable thickness gauge depends on understanding the materials you’re testing, the environment you’re working in, and the level of precision you require. Whether you’re monitoring wall thickness for corrosion, inspecting paint coatings, or conducting multi-material measurements, a well-matched gauge enhances productivity, quality, and safety.
