Measuring and Layout — FAQ
Can I use these infrared thermometers on humans?
No. These industrial thermometers are not FDA-approved for medical use and can give false readings. They measure surface temperature, not core body temperature. Use clinical thermometers for health screening.
What's the ideal distance-to-spot ratio for garage diagnostics?
A 10:1 ratio works for most tasks, measuring a 1-inch area from 10 inches away. For tight engine bays, 12:1 provides better precision. Lower ratios require closer proximity to hot components.
Why is adjustable emissivity important for automotive work?
Vehicle surfaces vary—polished aluminum intakes (0.05 emissivity) versus cast iron blocks (0.95). Without adjustment, readings can be off by 50°F or more. Adjustable models ensure accuracy across materials.
How accurate are these thermometers in real garage conditions?
Professional models like Fluke maintain ±1.5% accuracy even with dust and oil present. Budget models may drift ±3-5% after shop exposure. Regular calibration checks against boiling water ensure reliability.
Can IR thermometers measure through glass or plastic?
No. Infrared thermometers measure surface temperature only and cannot see through transparent materials. They'll read the glass temperature, not what's behind it. Remove obstructions for accurate measurements.
What separates a $30 thermometer from a $100+ professional model?
Durability, warranty, and calibration stability. Professional models survive drops, maintain accuracy in harsh conditions, and carry multi-year warranties. Budget units work for occasional use but fail under daily shop abuse.
