The Extech HD500 is a versatile 3-in-1 instrument that combines a psychrometer, Type K thermometer, and non-contact infrared thermometer into a rugged handheld housing. It is an ideal tool for home inspection, HVAC, and industrial diagnostics.

The built-in infrared thermometer features a 30:1 distance-to-target ratio and measures surface temperatures from -58 to 932°F (-50 to 500°C) with ±2% accuracy. The Type K thermometer function measures from -148 to 2501°F (-100 to 1372°C) using an included probe. The humidity meter measures 0–100% RH with ±2% accuracy, and calculates dew point (-90.4 to 140°F) and wet bulb (-6.88 to 140°F).

The HD500 includes a USB computer interface and software for data logging and analysis. Its combination of non-contact, contact, and environmental measurement capabilities makes it an all-in-one solution for comprehensive thermal and humidity assessment.