• USB interface for easy setup and data download
  • Selectable data sampling rate: 1second to 24 hours
  • Temperature Accuracy: ±1.8°F (14 to 104°F), ±3.6°F (all other ranges); ±1.0°C (-10 to 40°C), ±2.0°C (all other ranges)
  • Humidity Accuracy: ±3%RH (40 to 60%), ±3.5%RH (20 to 40 & 60 to 80%), ±5%RH (0 to 20 & 80 to 100%)
  • Software compatible with Windows 7, 8, 10

What's in the Box

  • 3.6V Lithium battery
  • Mounting bracket with combination lock
  • Windows compatible analysis software


The Extech RHT20 humidity & temperature data logger can log up to 16,000 humidity and 16,000 temperature readings with a user-programmable sample rate. The user can select a data sampling rate anywhere from 1 second to 24 hours. The Extech RHT20 features temperature accuracies down to ±1.8°F (±1.0°C) and humidity accuracies down to ±3% RH. This Extech data logger also allows user to program alarm thresholds for relative humidity and temperature.

Other features of the Extech RHT20 humidity & temperature data logger include an LCD display of current readings, minimum/maximum and alarm status and long battery life.