HOBO MX Soil Moisture and Temperature Data Logger
Specification
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 inchesSoil 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 |