HOBO U23 Pro v2 Temperature/Relative Humidity at S-bf_LL2

measurement of air temperature & air humidity in 2 m height; single point measurements, 30 min interval, 24/7 |
measurements since 2000; since 2015/2016: HOBO U23 Pro v2 Temperature/Relative Humidity Data Logger (Part # U23-001) in radiation shield HOBO RS1 from ONSET
The identically constructed sensor is installed at the monitoring sites Rh_LL1, S-bf_LL2, R-M1858_LL3, HM_LL4-bf, Kk_LL5, O-p_LL6, Gh_LL7 and Fk_LL8

technical description:

TEMPERATUR 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)

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)

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)
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.)