testo 623 Thermohygrometer is a compact and elegant solution for monitoring indoor temperature and humidity. Designed for both desktop and wall-mounted use, it provides reliable, continuous data with a 90-day history display, making it perfect for offices, living spaces, and commercial facilities.”
testo 623 is designed for the precise and reliable monitoring of indoor climate conditions. It features a versatile design suitable for placing on a desk or hanging on a wall. Users can customize measurement intervals from 5 minutes up to 24 hours, with automatic data logging for up to 90 days. The device also includes an Alarm function to alert users when readings exceed set limits.
Key Features:
Temperature – NTC
| Measuring range | -10 to +60 °C |
| Accuracy | ±0.4 °C |
| Resolution | 0.1 °C |
Humidity – Capacitive
| Measuring range | 0 to 100 %RH* |
| Accuracy | ±3 %RH Remaining Range |
| ±2 %RH + 1 Digit at +25 °C (10 to 90 %RH) | |
| Resolution | 0.1 %RH |
General technical data
| Weight | 240 g |
| Dimensions | 185 x 105 x 36 mm |
| Operating temperature | -10 to +60 °C |
| Measuring rate | 20 s |
| Product-/housing material | ABS |
| Protection class | IP30 |
| EU-/EG-guidelines | 2004/108/EG |
| Battery type | 4 x type AA batteries |
| Battery life | 12 Months |
| Storage temperature | -20 to +60 °C |



