The Lennox Y7842, manufactured by Amprobe, is a professional-grade THWD-3 relative humidity and temperature meter designed for accurate environmental measurements in HVAC, building diagnostics, and indoor air quality applications. This handheld digital meter allows technicians to quickly measure relative humidity, ambient temperature, wet bulb, and dew point, making it an essential tool for system commissioning, troubleshooting, and routine maintenance. The extended probe design enables reliable readings inside ducts and other hard-to-reach areas.

Built for field use, the Amprobe THWD-3 features a large dual LCD display for easy reading, min/max memory for tracking environmental changes, data hold functionality, and automatic power-off to conserve battery life. Its precision humidity sensor provides stable, repeatable results, supporting accurate HVAC performance evaluation and moisture diagnostics.

 

Specification:

Measurement functions: Relative humidity, ambient temperature, wet bulb temperature, dew point
Relative humidity range: 0 to 100 percent RH
Temperature range: −4°F to 140°F (−20°C to 60°C)
Display: Dual LCD with simultaneous readings
Features: Min/Max memory, data hold, auto power-off
Power supply: 9V battery
Application: HVAC service, duct testing, indoor air quality, building diagnostics