Overview
A weatherproof data logger with built-in temperature and relative humidity sensors. Leveraging Bluetooth technology for easy setup and data download directly to your mobile device or Windows computer running our free HOBOconnect app, this logger delivers high-accuracy measurements even in harsh outdoor environments.
Features
- Convenient wireless setup and download via Bluetooth (100-foot range)
- Retrieve data in hard-to-reach locations
- Visual alarms alert you to out-of-range conditions
- Compact, weatherproof housing with built-in mounting
- View current data in real-time with Onset’s free HOBOconnect app
- Share downloaded data easily from your mobile device
- Accuracy: +/- 0.2C° and +/- 2.5% RH
Specifications
| Temperature Sensor | ||||
| Range | MX2301A and MX2305 internal sensors: -40 to 70°C (-40 to 158°F) MX2302A external temperature sensor: -40 to 70°C (-40 to 158°F) MX2303 and MX2304 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 | ±0.25°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) ±0.25°C from 70 to 100°C (±0.45 from 158 to 212°F), MX2303 and MX2304 only | |||
| Resolution | MX2301A and MX2302A: 0.02°C (0.036°F) MX2303, MX2304, and MX2305: 0.04°C (0.072°F) | |||
| Drift | <0.01°C (0.018°F) per year | |||
| Relative Humidity Sensor* (MX2301A, MX2302A only) | ||||
| 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% (typical) to a maximum of ±3.5% including hysteresis at 25°C (77°F); below 10% RH and above 90% RH ±5% typical | |||
| Resolution | 0.01% | |||
| Drift | <1% per year typical | |||
| Response Time (typical, to 90% of change) | ||||
| Temperature | Without Solar Radiation Shield | With RS1/M-RSA Solar Radiation Shield | With RS3-B Solar Radiation Shield | |
| MX2301A internal sensor | 17 minutes in air moving 1 m/sec | 24 minutes in air moving 1 m/sec | NA | |
| MX2302A external sensor | 3 minutes, 45 seconds in air moving 1 m/sec | 7 minutes, 45 seconds in air moving 1 m/sec | 6 minutes, 30 seconds in air moving 1 m/sec | |
| MX2303/MX2304 external sensors | 3 minutes in air moving 1 m/sec; 20 seconds in stirred water | 7 minutes in air moving 1 m/sec | 4 minutes in air moving 1 m/sec | |
| MX2305 internal sensor | 17 minutes in air moving 1 m/sec | 24 minutes in air moving 1 m/sec | NA | |
| RH | Without Solar Radiation Shield | With RS1/M-RSA Solar Radiation Shield | With RS3-B Solar Radiation Shield | |
| MX2301A internal sensor | 30 seconds in air moving 1 m/sec | 40 seconds in air moving 1 m/sec | NA | |
| MX2302A external sensor | 15 seconds in air moving 1 m/sec | 30 seconds in air moving 1 m/sec | 30 seconds in air moving 1 m/sec | |
| Logger | ||||
| Operating Range | -40° to 70°C (-40° to 158°F) | |||
| Radio Power | 1 mW (0 dBm) | |||
| Transmission Range | Approximately 30.5 m (100 ft) line-of-sight | |||
| Wireless Data Standard | Bluetooth Low Energy (Bluetooth Smart) | |||
| Logging Rate | 1 second to 18 hours | |||
| Logging Modes | Fixed interval (normal, statistics) or burst | |||
| Memory Modes | Wrap when full or stop when full | |||
| Start Modes | Immediate, push button, date & time, or next interval | |||
| Stop Modes | When memory full, push button, date & time, or after a set logging period | |||
| Time Accuracy | ±1 minute per month 0° to 50°C (32° to 122°F) | |||
| Battery Type | 2/3 AA 3.6 Volt lithium, user replaceable | |||
| Battery Life | 2 years, typical with logging interval of 1 minute and Bluetooth Always On enabled; 5 years, typical with logging interval of 1 minute and Bluetooth Always On disabled. Faster logging intervals and statistics sampling intervals, burst logging, remaining connected with the app, excessive downloads, and paging may impact battery life. | |||
| Memory | MX2301A and MX2302A: 128 KB (63,488 measurements, maximum) MX2303, MX2304, and MX2305: 128 KB (84,650 measurements, maximum) | |||
| Full Memory Download Time | Approximately 60 seconds; may take longer the further the device is from the logger | |||
| Dimensions | Logger housing: 10.8 x 5.08 x 2.24 cm (4.25 x 2.0 x 0.88 in.) External temperature sensor diameter: 0.53 cm (0.21 in.) External temperature/RH sensor diameter: 1.17 cm (0.46 in.) External sensor cable length: 2 m (6.56 ft) Solar radiation shield bracket: 10.8 x 8.3 cm (4.25 X 3.25 in.) | |||
| Weight | Logger: 75.5 g (2.66 oz) Solar radiation shield bracket: 20.4 g (0.72 oz) | |||
| Materials | Acetal, silicone gasket, stainless steel screws | |||
| Environmental Rating | NEMA 6 and IP67 | |||
*Per RH sensor manufacturer data sheet
