| Temperature Sensor |
Operation Range |
U23-001A: -40 to 70°C
U23-002A: -40 to 70°C
U23-003 / U23-004: -40 to 100°C (immersion up to 50°C for 1 year) |
| Accuracy |
U23-001A / U23-002A: ±0.25°C (-40 to 0°C), ±0.2°C (0 to 70°C)
U23-003 / U23-004: ±0.21°C (0 to 50°C) |
| Resolution |
U23-001A / U23-002A: 0.04°C
U23-003 / U23-004: 0.02°C at 25°C |
| Response Time |
U23-001A: 10 minutes (air)
U23-002A: 3 min 45 sec (air)
U23-003 / U23-004: 3 min (air), 30 sec (water) |
| Drift |
U23-001A / U23-002A: <0.01°C/year
U23-003 / U23-004: <0.1°C/year |
| RH Sensor (U23-001A & U23-002A) |
Operation Range |
0 to 100% RH, -40 to 70°C |
| Accuracy |
±2.5% (10%–90% RH typical)
±3.5% max incl. hysteresis
±5% outside range |
| Resolution |
0.05% |
| Response Time |
U23-001A: 40 minutes (air, with cap)
U23-002A: 15 seconds (air) |
| Drift |
<1% per year typical |
| Logger |
Operation Range |
-40 to 70°C |
| Real-time Clock |
±1 minute/month (0° to 50°C) |
| Battery |
1/2 AA 3.6V lithium (replaceable) |
| Battery Life |
3 years (logging interval ≥1 minute) |
| Memory |
64 KB (~21,000 measurements) |
| Launch Modes |
Immediate start, delayed start |
| Logging Interval |
1 second to 18 hours (up to 8 intervals) |
| Offload Modes |
Offload while logging or stop & offload |
| Battery Indication |
Displayed in status screen and datafile |
| Materials |
ASA polymer housing, polypropylene cap, Buna-N o-ring,
RH models include hydrophobic membrane |
| Cables |
U23-001A |
No cable |
| U23-002A |
1.84 m cable, sensor Ø 1 cm |
| U23-003 |
2 × 1.84 m cables, sensor Ø 0.5 cm |
| U23-004 |
1.84 m cable, sensor Ø 0.5 cm |
| Physical |
Environmental Rating |
NEMA 6P (housing, submersible)
NEMA 4 (RH models, splash-resistant) |
| Weight |
U23-001A: 57 g
U23-002A: 118 g
U23-003: 138 g
U23-004: 102 g |
| Dimensions |
10.2 × 3.8 cm (4.0 × 1.5 in) |
| NIST Certificate |
Available (optional) |