HOBO UX100-023A External Temp/RH Data Logger

Product Options


The HOBO UX100-023 External Temperature/Relative Humidity data logger records temperature and relative humidity in an indoor environment with its external sensor. Ideal for monitoring occupant comfort in office buildings, tracking food storage conditions in warehouses, logging temperature trends in server rooms, and measuring humidity levels in museums.

Manufactured by: Onset
Model: HOBO UX100-023A External Temp/RH Data Logger

Services offered for this product

  • Sales
  • Rental
  • Installation
  • Calibration
  • Maintenance


Dew point
Relative humidity


Temperature Sensor
Range -20° to 70°C (-4° to 158°F)
Accuracy ±0.21°C from 0° to 50°C (±0.38°F from 32° to 122°F)
Resolution 0.024°C at 25°C (0.04°F at 77°F)
Response time 3 minutes, 45 seconds in air moving 1 m/s (2.2 mph)
Drift <0.1°C (0.18°F) per year
RH Sensor
Range 1% to 100% RH at -40° to 75°C (-40° to 167°F), non-condensing; exposure to conditions below -20°C (-4°F) or above 95% RH may temporarily increase the maximum RH sensor error by an additional 1%
Accuracy ±2.5% from 10% to 90% RH typical to a maximum of ±3.5% including hysteresis at 25°C (77°F); below 10% and above 90% ±5% typical
Resolution 0.01%
Response time 15 seconds to 90% in airflow of 1 m/s (2.2 mph)
Drift <1% per year typical
Cable length 1.83 m (6 ft)
Logger Operating Range
Logging -20° to 70°C (-4° to 158°F); 0 to 95% RH (non-condensing)
Launch/readout 0° to 50°C (32° to 122°F) per USB specification
Logging rate 1 second to 18 hours, 12 minutes, 15 seconds
Logging modes Normal, Burst or Statistics
Memory modes Wrap when Full or Stop when Full
Start modes Immediately, Push Button, Date & Time or Next Interval
Stop modes When Memory Full, Push Button, or Date & Time
Restart mode Push Button
Time accuracy ±1 minute per month at 25°C (77°F)
Battery life 1 year, typical with logging rate of 1 minute and sampling interval of 15 seconds or greater
Battery type One 3V CR2032 lithium battery
Memory 128 KB (63,488 measurements, maximum)
Download type USB 2.0 interface
Full memory download time 20 seconds
LCD LCD is visible from: 0° to 50°C (32° to 122°F); the LCD may react slowly or go blank in temperatures outside this range
Size 3.66 x 8.48 x 2.29 cm (1.44 x 3.34 x 0.9 in.)
Weight 30 g (1.06 oz)
Environmental rating  IP50
The CE Marking identifies this product as complying with all relevant directives in the European Union (EU)