The HOBO U23 Pro v2 data loggers are weatherproof with different options depend on the user necessity.
The HOBO Pro v2 Temperature/Relative Humidity data logger U23-001 is a data logger with built-in temperature and relative humidity sensors. The Relative Humidity sensor provides superior durability in humid environments and is user replaceable.
The HOBO Pro v2 External Temperature/Relative Humidity Data Logger U23-002 is a data logger with an external Temperature and Relative Humidity sensor on a 6-foot cable for fast sensor response and deployment in tight spaces. The Relative Humidity sensor features fast response and superior durability in humid environments, and is user-replaceable.
The HOBO Pro v2 2x External Temperature Data Logger U23-003 is a data logger with two external soil/water temperature probes on 6-foot cables for fast sensor response and deployment in tight spaces.
The HOBO Pro v2 Temperature/External Temperature data logger is a data logger with an external soil/water temperature sensor on a 6-foot cable useful for situations where just one temperature probe is required. An internal temperature sensor is also included.
IMPORTANT: HOBO data loggers require HOBOware software (USB interface cable included w/CD purchase). See compatible items below and connection HOBO Optic USB Base Station interface above right.
Temperature Sensor Operation range Internal sensors: -40° to 70°C (-40° to 158°F) U23-002 external temperature sensor: -40° to 70°C (-40° to 158°F) U23-003 and U23-004 external sensors: -40° to 100°C (-40° to 212°F), with tip and cable immersion in fresh water up to 50°C (122°F) for one year.
Accuracy: ±0.21°C from 0° to 50°C (±0.38°F from 32° to 122°F); see Plot A.
Resolution: 0.02°C at 25°C (0.04°F at 77°F); see Plot A Response time (typical to 90%) U23-001 Internal sensor: 40 minutes in air moving 1 m/sec U23-002 external temperature sensor: 5 minutes in air moving 1 m/sec U23-003 and U23-004 external sensors: 3 minutes in air moving 1 m/sec; 30 seconds in stirred water Stability (drift): < 0.1°C (0.18°F) per year.
Relative Humidity Sensor (U23-001, U23-002 only) Operation range 0-100% RH, -40° to 70°C (-40° to 158°F) 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. See Plot B for full range.
Resolution: 0.03% Response time (typical to 90%) U23-001: 40 minute in air moving 1 m/sec with protective cap U23-002: 5 minutes in air moving 1 m/sec with protective cap Stability (drift) < 1% per year typical.
Logger Operation range -40° to 70°C (-40° to 158°F) Real-time clock ± 1 minute per month 0° to 50°C (32° to 122°F) Battery 1/2 AA, 3.6 Volt lithium, user-replaceable (part # HP-B) Battery life (typical use): 3 years with 1 minute or greater logging interval Memory (non-volatile): 64K bytes memory (approx. 21,000 temperature and RH measurements).
Cables: U23-001: No cables. U23-002: One 184 cm (6 ft) PVC cable; sensor diameter 1 cm (0.38 in). U23-003: Two 184 cm (6 ft) PVC cables; sensor diameter 0.5 cm (0.20 in). U23-004: One 184 cm (6 ft) PVC cable; sensor diameter 0.5 cm (0.20 in).
Environmental rating: Electronics housing is NEMA 6P equivalent (tolerant of brief submergence). Units with RH sensors are NEMA 4 equivalent (splash-resistant).
Launch modes: Immediate start; delayed start.
Logging interval: 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).
Offload modes: Offload while logging; stop and offload.
Battery indication: Battery voltage can be viewed in status screen and optionally logged in datafile. Low battery indication in datafile.
Weight: U23-001: 57 g (1.5 oz). U23-002: 118 g (3.1 oz). U23-003: 138 g (3.7 oz). U23-004: 102 g (2.7 oz).
Dimensions: Housing measures 10.2 × 3.8 cm (4.0 × 1.5 in.). NIST certificate Temperature available for additional charge. The CE Marking identifies this product as complying with the relevant directives in the European Union (EU).