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Pro v2 Temperature & Relative Humidity Data Logger


The HOBO Pro v2 Temperature/Relative Humidity data logger is a weatherproof data logger with built-in temperature and relative humidity sensors. The Relative Humidity sensor provides superior durabili..

  • Brands Onset
  • Product Code: U23-001
  • Availability: 7-10 Days

Tags: u23-001, pro, v2, temperature, relative, humidity, data, logger, built-in, hoboware, u-dtw-1, shuttle

Temperature & Relative Humidity Pro v2 Data Logger

The HOBO Pro v2 Temperature/Relative Humidity data logger is a weatherproof data logger with built-in temperature and relative humidity sensors. The Relative Humidity sensor provides superior durability in humid environments and is user-replaceable.


Highlighted Features


  • Weatherproof housing for use in outdoor or condensing environments
  • High accuracy
  • Replaceable Relative Humidity sensor provides fast response and superior recovery from condensing conditions
  • Small-diameter external sensor versions for measurements in tight spaces
  • An optic USB interface for fast and reliable download
  • Compatible with HOBOware and HOBOware Pro software for logger setup, graphing and analysis (HOBOware Pro is required when using the U-DTW-1 Waterproof shuttle)



In what environment does this data logger operate?

This data logger operates in an outdoor environment.


What measurements does this data logger support?

The U23-001 data logger supports the following measurements: Relative Humidity and Temperature


For more information visit Onset



  • HOBO U23-001 Pro v2 Temp/RH Data Logger
  • Clamp and mounting screws
  • UV protective cap


The following are associated resources for this product. In general users of this product can gain insight into its possible use by utilizing the resources below.


White Papers

On-Demand Webinars

How-To Videos

Informational Pages

Application Stories

Tech Notes

Self-Guided Training

Forum Postings

Bluetooth or USB Field Temp/RH Data Loggers: Which is Right for You? Choosing the Right Temp/RH Data Logger to Meet Your Needs HOBOware Menus Explained Part 1 Tips on Buying a Data Logger Data Loggers Aid Site Selection Process at Fruit Farm A quick temp-accuracy check (ice bath) Working with Onset’s Outdoor Stand-alone Family of Loggers "No Hobo-ware onset shuttles attached" error
  Data Logger Basics HOBOware Menus Explained Part 2 What is a Data Logger? Data Loggers Improve Turf Management at Camden Yards Data Assistant Videos on YouTube   Problems with data from Hobo Po V2
  Evaluating Moisture Damage with HOBO Temp/RH Loggers How to automatically launch multiple HOBO USB data loggers   Data Loggers Monitor Lakes for Signs of Global Warming How do I delete, erase, or clear data from my data logger's memory?    
    How to automatically readout and save data from a HOBO USB data logger   Data Loggers Preserve the Catch of the Day Optic data logger not recognized by HOBOware using Windows 8.1 or Windows 10    
    How to change your default units preference in HOBOware   Data Loggers Track Wildfire Behavior Proper Coupler Seating, BASE-U-4 (Optic Base station) and the U-DTW-1 (Waterproof Shuttle)    
    How to import text files into HOBOware Pro   Data Loggers Used in Microclimate Monitoring Logger power failure and data loss    
    How to navigate the HOBOware plot screen   Group’s Experiments Seek the Perfect Bluebird House Protecting data loggers from electrical discharge (ESD)    
    HOBOware Pro's Grains Per Pound Assistant   NASA Uses Data Loggers to Study Volcanic Park Conditions Verifying RH accuracy on HOBO data loggers    
    Visit Onset's YouTube Channel   New Mexico Vineyard Adds Weather Station for Frost Protection Waterproof shuttle for beginners    


Enclosure Material All models: ASA styrene polymer housing and mounting clamp; polypropylene protective cap; Buna-N o-ring(s) U23-001, U23-002 only: ASA styrene polymer RH sensor cap; modified hydrophobic polyethersulfone membrane
Launch Modes Immediate start; delayed start
Logger Battery Indication Battery voltage can be viewed in status screen and optionally logged in datafile. Low battery indication in datafile.
Logger Battery Life 3 years with 1 minute or greater logging interval
Logger Battery Type 1/2 AA, 3.6 Volt lithium, user-replaceable (part # HP-B)
Logger Dimensions Housing measures 10.2 × 3.8 cm (4.0 × 1.5 in.)
Logger Environmental Rating Electronics housing is NEMA 6P equivalent (tolerant of brief submergence). Units with RH sensors are NEMA 4 equivalent (splash-resistant).
Logger Memory 64K bytes memory (approx. 21,000 temperature and RH measurements)
Logger Offload Modes Offload while logging; stop and offload
Logger Operating Range -40° to 70°C (-40° to 158°F)
Logger Weight 57 g (1.5 oz)
Logging Intervals Fixed-rate or multiple logging intervals, with up to 8 user-defined logging intervals and durations; logging intervals from 1 second to 18 hours (refer to HOBOware software manual)
NIST Certificate Temperature certificate available for additional charge
Real-time Clock ± 1 minute per month 0° to 50°C (32° to 122°F)
Relative Humidity Sensor
Relative Humidity Sensor 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
Relative Humidity Sensor Drift < 1% per year typical
Relative Humidity Sensor Resolution 0.05%
Relative Humidity Sensor Response Time 40 minute in air moving 1 m/sec with protective cap
Response Time
Response Time Temperature 40 minutes in air moving 1 m/sec
Safety and Regulatory
Safety and Regulatory CE The CE Marking identifies this product as complying with the relevant directives in the European Union (EU).
Temperature Sensor
Temperature Sensor Accuracy ±0.21°C from 0° to 50°C (±0.38°F from 32° to 122°F)
Temperature Sensor Drift < 0.1°C (0.18°F) per year
Temperature Sensor Operating Range -40° to 70°C (-40° to 158°F)
Temperature Sensor Resolution 0.02°C at 25°C (0.04°F at 77°F); see Plot A in the manual