HOBO MX Soil Moisture Data Loggers are the industry’s only low-cost, fully integrated soil moisture loggers with Bluetooth wireless data offload. Available in two models – one that measures soil moisture (HOBO MX2306) and one that measures both soil moisture and temperature (HOBO MX2307) – these loggers are ideal for researchers and growers looking for the accurate data they need to save water, improve crop yields, reduce harmful runoff, and protect ecosystems.
With just a mobile phone, tablet, or Windows laptop running Onset’s free HOBOconnect app, users get convenient wireless setup and data download via Bluetooth when within 100 feet of the logger – making it easy to retrieve data from hard-to-access field locations. And for indoor areas, such as greenhouses, users can add the MX Gateway for remote access to data in Onset’s cloud-based HOBOlink software.
Manufactured by: Onset
Model: HOBO MX Soil Moisture and Temperature Data Logger
Soil Moisture
Temperature
Soil Moisture: Volumetric Water Content (VWC) | |
Measurement Range* |
0.00 to 0.64 m³/m³ in mineral soils 0.00 to 0.70 m³/m³ in soilless media |
Accuracy | ±0.031 m³/m³ typical in mineral soils that have solution EC <8 dS/m>
±0.051 m³/m³ typical in soilless media |
Resolution | 0.001 m³/m³ |
Dielectric Measurement Frequency | 70 MHz |
Temperature Sensor (MX2307) | |
Range | -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) |
Resolution | 0.04°C (0.072°F) |
Drift | <0.01°C per year (0.018°F per year) |
Response Time | 3 minutes in air moving 1 m/s; 20 seconds in stirred water 4 minutes in air moving 1 m/s with RS3-B Solar Radiation Shield |
Logger | |
Operating Range | -25° to 60°C (-13° to 140°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 | 110,000 measurements, maximum (472 kB) |
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.) Soil moisture sensor: 7.5 x 5.1 x 2.4 cm (2.95 x 2.02 x 0.95 inches) Soil moisture sensor needle length: 5.4 cm (2.13 inches) Soil moisture sensor needle diameter: 0.32 cm (0.13 inches) Temperature sensor (MX2307) diameter: 0.53 cm (0.21 in.) Sensor cable length: 2 m (6.56 ft) |
Weight | MX2306: 229 g (80 oz) MX2307: 267 g (94 oz) |
Materials | Logger: Acetal, silicone gasket, stainless steel screws Soil Moisture Sensor: ASA plastic body with polyurethane epoxy filling and stainless steel pins Temperature Sensor (MX2307): Stainless steel waterproof tip Cable: PVC, UV resistant and rodent repellent (soil moisture sensor cable) |
Environmental Rating | Temperature sensor and cable (MX2307): Immersion in water up to 50°C (122°F) for 1 year |
* The sensor data can be post-calibrated if necessary (e.g. the sensor is used in non-mineral soil types or higher than standard accuracy is required). Users can apply a calibration equation to the data exported from the app. The VWC range will depend on the calibration equation. |