Measuring and Layout — FAQ
What materials can sub-$25 thickness gauges measure?
Most budget gauges handle paper, plastic, leather, and thin metal sheet up to 1 inch. Ultrasonic models measure thick steel, glass, and PVC pipes. Automotive paint meters specialize in ferrous and non-ferrous metals. Always verify the measurement range and type before purchasing.
How accurate are these budget thickness gauges?
Digital gauges under $25 typically achieve ±0.01mm accuracy, while precision models reach ±0.001mm. Ultrasonic units measure ±0.1mm on thick materials. Paint meters achieve ±3%+2μm accuracy. These specs suffice for DIY, crafting, and light professional use but not aerospace or medical applications.
Should I choose digital or mechanical?
Choose digital for instant readings, unit conversion, and fine resolution—ideal for crafting, quality control, and automotive work. Pick mechanical for welding, field service, and harsh environments where batteries fail and electronics risk damage. Digital offers convenience; mechanical offers bulletproof reliability.
Can these gauges measure car paint thickness?
Yes, but you need a dedicated paint thickness meter with Fe/NFe modes. The CM-205FN and automotive-specific models detect original vs. repainted panels. General-purpose digital gauges cannot measure paint layers—they're designed for solid materials, not thin coatings on metal substrates.
What's the difference between mil and millimeter?
One mil equals 0.001 inch or 25.4 micrometers. One millimeter equals 39.37 mils. Automotive paint is measured in mils (typically 4-8 mils). Paper and crafting materials use mm or inches. Quality gauges display both units; always verify you're reading the correct scale.
Do budget thickness gauges require calibration?
Digital gauges arrive pre-calibrated but should be zeroed on a flat surface before each session. Ultrasonic models include calibration blocks. Mechanical gauges never need calibration. For critical measurements, verify accuracy monthly against known standards—budget tools can drift over time.
