Extech RH550 Humidity Meter with Datalogger, Dew Point and Mold Warning

Facility managers, HVAC technicians, and building inspectors use the Extech RH550 to monitor indoor climate conditions in offices, warehouses, and residential buildings. It measures relative humidity, air temperature, dew point, and wet bulb temperature, and logs up to 100,000 readings for later analysis.

Key specifications

• Relative humidity: 0 to 100% RH, accuracy ±2% (10-90% RH), resolution 0.01% RH
• Air temperature: -20 to 70°C (-4 to 158°F), accuracy ±0.5°C, resolution 0.01°C/°F
• Dew point: -30 to 100°C (-22 to 212°F); wet bulb: 0 to 80°C (32 to 176°F)
• Datalogging: up to 100,000 readings, sample rate 1 second to 24 hours
• USB interface and PC software for data transfer
• Backlit LCD, high/low alarms, dew point and mold warning
• Powered by 3 AAA batteries, auto power off, tripod mount

Why choose it

The RH550 combines a high-accuracy hygrometer with a versatile datalogger and moisture-related alerts. Its dew point and mold warning help prevent condensation and mold growth, while the large memory and USB connectivity simplify long-term monitoring and reporting.

Ideal use cases

• HVAC system testing and balancing
• Building diagnostics and mold prevention inspections
• Storage environment monitoring for sensitive materials
• Laboratory and cleanroom humidity verification

Good to know

The meter is tripod-mountable for hands-free operation and includes PC software for data analysis. Auto power off extends battery life during field use.