The Extech RHT20 is a compact, standalone USB datalogger that records up to 16,000 readings each for relative humidity (0 to 100% RH) and temperature (–40 to 158°F / –40 to 70°C). Designed for environmental monitoring in warehouses, cold storage, shipping containers, offices, and laboratories, it features a user-selectable sampling interval from 1 second to 24 hours and includes a built-in LCD that displays real-time, Min/Max, and alarm status. Data is easily downloaded via USB to a Windows® PC using the included software. The unit also includes a mounting bracket with a combination lock for secure placement and is powered by a long-life 3.6V lithium battery.
| Temperature | –40 to 158°F (–40 to 70°C) | 0.1°F/°C |
±1.8°F (±1.0°C) from 14 to 104°F (–10 to 40°C) ±3.6°F (±2.0°C) outside that range |
| Relative Humidity | 0 to 100% RH | 0.1% RH |
±3% RH (40–60% RH) ±3.5% RH (20–40% & 60–80% RH) ±5% RH (0–20% & 80–100% RH) |
| Datalogging Capacity | 16,000 points per parameter | — | — |
| Sampling Interval | 1 second to 24 hours | — | — |
| Power Source | 3.6V lithium battery (included) | — | — |
| Dimensions | 3.7 x 1.9 x 1.2" (94.4 x 48.9 x 31.2 mm) | — | — |
| Weight | 3.2 oz (90.7 g) | — | — |
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The Extech RHT20 is a compact, standalone USB datalogger that records up to 16,000 readings each for relative humidity (0 to 100% RH) and temperature (–40 to 158°F / –40 to 70°C). Designed for environmental monitoring in warehouses, cold storage, shipping containers, offices, and laboratories, it features a user-selectable sampling interval from 1 second to 24 hours and includes a built-in LCD that displays real-time, Min/Max, and alarm status. Data is easily downloaded via USB to a Windows® PC using the included software. The unit also includes a mounting bracket with a combination lock for secure placement and is powered by a long-life 3.6V lithium battery.
| Temperature | –40 to 158°F (–40 to 70°C) | 0.1°F/°C |
±1.8°F (±1.0°C) from 14 to 104°F (–10 to 40°C) ±3.6°F (±2.0°C) outside that range |
| Relative Humidity | 0 to 100% RH | 0.1% RH |
±3% RH (40–60% RH) ±3.5% RH (20–40% & 60–80% RH) ±5% RH (0–20% & 80–100% RH) |
| Datalogging Capacity | 16,000 points per parameter | — | — |
| Sampling Interval | 1 second to 24 hours | — | — |
| Power Source | 3.6V lithium battery (included) | — | — |
| Dimensions | 3.7 x 1.9 x 1.2" (94.4 x 48.9 x 31.2 mm) | — | — |
| Weight | 3.2 oz (90.7 g) | — | — |