Onset HOBO U23 Pro v2 Temp/RH Loggers
Features
- Weatherproof housing for use in outdoor or condensing environments
- Small-diameter external sensor versions for measurements in tight spaces
- Optic USB interface for fast and reliable download
- Expedited repair and warranty service
- Lifetime technical support
- More
Overview
The Onset HOBO Pro v2 logger’s environmentally rugged case is designed for years of reliable use in outdoor applications. It has enough memory to record over 42,000 12-bit measurements.
Data
The logger uses an optical USB communications interface (via a compatible shuttle or base station) for launching and reading out the logger. The optical interface allows the logger to be offloaded without compromising the electronics. The USB compatibility allows for easy setup and fast downloads.
Temperature Sensor | |
Operation Range | U23-001A internal sensor: -40 to 70°C (-40 to 158°F) U23-002A 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 | U23-001A and U23-002A: ±0.25°C from -40 to 0°C (±0.45 from -40 to 32°F), ±0.2°C from 0 to 70°C (±0.36 from 32 to 158°F) U23-003 and U23-004: ±0.21°C from 0° to 50°C (±0.38°F from 32° to 122°F); see Plot A |
Resolution | U23-001A and U23-002A: 0.04°C (0.072°F) U23-003 and U23-004: 0.02°C at 25°C (0.04°F at 77°F); see Plot A |
Response Time (Typical to 90%) |
U23-001A internal sensor: 10 minutes in air moving 1 m/sec U23-002A external temperature sensor: 3 minutes, 45 seconds 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 |
Drift | U23-001A and U23-002A: <0.01°C (0.018°F) per year U23-003 and U23-004: <0.1°C (0.18°F) per year |
Relative Humidity Sensor (U23-001A, U23-002A only) | |
Operation Range | 0 to 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 at 25°C (77°F); below 10% and above 90% ±5% typical |
Resolution | 0.05% |
Response Time (Typical to 90%) |
U23-001A: 40 minutes in air moving 1 m/sec with protective cap U23-002A: 15 seconds in air moving 1 m/sec |
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 (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) |
Materials | All models: ASA styrene polymer housing and mounting clamp; polypropylene protective cap; Buna-N o-ring(s); U23-001A, U23-002A only: ASA styrene polymer RH sensor cap; modified hydrophobic polyethersulfone membrane |
Cables | U23-001A: No cables U23-002A: 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 |
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 | U23-001A: 57 g (1.5 oz); U23-002A: 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 certificate available for additional charge |
- HOBO U23 Pro v2 Temp/RH Logger
- Clamp and mounting screws
- UV protective cap
In The News
Combating Water Insecurity in Saskatchewan with Real-Time Data
The prairies of Saskatchewan can be described as one of the least water-secure parts of Canada, making water quality monitoring essential for informed resource management in a region already facing water insecurity. While natural physical properties worsen some of the poor water quality conditions in the region, others are connected to land use. 
 
Having grown up spending summers on the shores of Lake Huron, Helen Baulch, an associate professor at the School of Environment and Sustainability at the University of Saskatchewan , has always been dedicated to the protection of water resources. 
 
Looking back fondly at her childhood playing along the shore, Baulch also recalls the invasion of quagga mussels during her teenage years and watching the lake change as a result.
Read MoreSeametrics Turbo Turbidity Logger: Boost your Turbidity Monitoring
The Seametrics Turbo Turbidity Logger is a self-cleaning turbidity sensor capable of internally logging over 260,000 data records. The sensor enables researchers, compliance officers, and contractors to monitor turbidity in various applications, from construction and dredging sites to wastewater effluent. 
 
 Due to its narrow width, this device can be deployed in a range of areas, from small well spaces to rivers and streams. The stainless steel housing and built-in wiper allow the sensor to withstand long-term deployments and reduce the need for maintenance trips. 
 
 The logger accurately records temperature and turbidity up to a depth of 50 meters.
Read MoreCollecting Data at the Top of the World: How Scientists Retrieve Glacial Ice Cores
A helicopter touches down in the small town of Sicuani, Peru, at an elevation of 11,644 feet. Earlier that day, a boxcar brought fuel, drills, food, and other equipment for a glacial expedition. The year is 1979, and glaciologist Lonnie Thompson is preparing to lead a team to the Quelccaya ice cap in hopes of becoming the first scientists to drill an ice core sample from this glacier. 
 
 The only problem? The glacier is located at 19,000 feet in one of the most remote areas of the world. The helicopter takes off from the town, but the thin atmosphere at that elevation does not allow it to safely touch down on the ice– due to the aircraft’s weight, and it becomes unstable when the air is less dense.
Read More