Bluetooth Stainless Steel Research Grade Water Level Data Logger, 0 to 13 ft
- Recording Water Level (Depth) and Temperature in Wet or Water Environments
- -20°C to 50°C Temperature Measurement Range with ±0.20°C Accuracy
- Factory-Replaceable 2/3 AA 3.6 Volt Lithium Battery with 10 Year Life (5-Minute Sampling Rate)
- Download Data Using Bluetooth Communications
- Setup, Configure and View Reports Online via HOBOconnect App or Browser
- 0 to 13 ft Water Level Range with Stainless Steel Housing
MX20-04 HOBO MX20 Research-Grade Water Level Data Logger
The HOBO MX20-04 is a research-grade water level data logger engineered for accurate, long-term monitoring of groundwater wells, streams, lakes, reservoirs, and other freshwater environments. With a 13 ft (4 m) depth range and a rugged 316 stainless steel housing built for freshwater, the MX20-04 delivers laboratory-grade water level, water temperature, and barometric-compensated pressure data in a compact, narrow-diameter form factor that fits inside 2-inch wells.
Each MX20-04 ships with a 3-point NIST-traceable calibration certificate and uses a reliable absolute pressure sensor — eliminating the vent tubes and desiccants that clog, freeze, and fail in competing vented designs. Integrated Bluetooth 5 LE lets field technicians offload data wirelessly to the free HOBOconnect mobile app, which automatically converts raw pressure to fully compensated water level readings accounting for barometric pressure, temperature, and water density.
Why choose the MX20-04?
- Research-grade accuracy for groundwater studies, regulatory reporting, water resource management, and scientific research
- 13 ft (4 m) measurement range with typical water level error of just ±0.3 cm (0.01 ft) water
- 316 stainless steel construction optimized for freshwater — ideal for wells, streams, and freshwater bodies
- Wireless Bluetooth offload — no cables, no cradles, no proprietary readout units
- Vent-free absolute pressure sensor eliminates clogging, freezing, and desiccant maintenance
- Up to 10-year deployment life and ~400,000 measurement sets of onboard memory
- Compact 2.46 cm (0.97 in) diameter fits narrow wells while leaving room for suspension cables
- IP68-rated, fully submersible, with 3-point NIST-traceable calibration included
Ideal applications
The stainless steel MX20-04 is ideal for freshwater applications: monitoring wells, aquifer and groundwater studies, stream and river stage, lakes, reservoirs, stormwater, and wetland research where long-term, regulatory-grade accuracy is required.
HOBO™ MX20-04 Bluetooth Research Grade Water Level Data Logger Specifications
| Data Channels | 1 Temperature Channel 1 Pressure/Water Level Channel |
| Water Level | Measurement Range: 0 to 4m (0 to 13ft) - Sea Level; 0 to 7m (0 to 23ft) @ 3,000m Altitude Typical Accuracy: ±0.075% FS (Full Scale), 0.14 cm (0.005 ft) Water Maximum Accuracy: ±0.15% FS (Full Scale), 0.6 cm (0.002 ft) Water Resolution: 0.14 cm (0.005 ft) Water NOTE: Measurement Accuracy Also Depends on Temperature Response Time |
| Pressure (Absolute) |
Pressure Range: 0 to 145kPa (0 to 21 psia) Calibrated Range: 69 to 145 kPa (10 to 21 psia) @ 0°C to 40°C Burst Pressure: 310 kPa (45 psia) or 18 m (60 ft) depth Raw Pressure Accuracy: ±0.3% FS (Full Scale), 0.43 kPa (0.063 psi) - Max Error Resolution: <0.014 kPa (0.0002 psi) Response Time: <1 Second @ Stable Temperature to 90% |
| Temperature | Measurement Range: -20°C to 50°C (-4°F to 122°F) Accuracy: ±0.2°C from 0°C to 50°C (±0.36°F from 32°F to 122°F) Resolution: 0.002°C at 25°C (0.04°F at 77°F) Response Time: 5 Minutes in Water to 90% (Typical) Stability (Drift): 0.1°C (0.18°F) per Year |
| Sampling Rate | 1 Second to 18 Hours (User-Specified) |
| Data Storage Capacity | 400,000 Pressure and Temperature Readings (When Bluetooth Communications Not Available) |
| Power Source | 2/3 AA 3.6 Volt Lithium Battery (Factory-Replaceable) |
| Battery Life | 3 Years: 1 Minute Logging and Bluetooth Always On 7 Years: 1-Minute Logging and Bluetooth Off and LED Off 10 Years: 5-Minute Logging and Bluetooth Off and LED Off |
| Communications | Type: Bluetooth Wireless Wireless Data Standard: Bluetooth Smart (Bluetooth Low Energy, Bluetooth 5.0) Transmission Range: Approximately 3ft to 10 ft Line of Sight Radio Power: 1 mW (0 dBm) |
| Logging Mode | Fixed Interval (Normal or Statistics), Burst or Multiple Intervals with up to 8 User-Defined Intervals and Durations |
| Start Mode | Immediately, Push Button, Date & Time or Next Interval |
| Stop Mode | Memory Full, Wrap When Data Storage Full, Push Button, Date & Time or After Set Interval |
| Alarms | High or Low Alarm Events, Logged and Alarm Status Shown in HOBOconnect App |
| Battery Indication | Battery status shown in HOBOconnect app (approximate) |
| Time Accuracy | ±1 Minute per Month @ 25°C |
| Software | HOBOconnect Software App for iOS and Android Note: Bluetooth 5.0 is Required on your Mobile Device (Phone or Tablet) |
| OS Compatibility | Android Phones and Tablets iPhone, iPad, iPod Touch with iOS 7.1 or Later Bluetooth 4.0 or Later |
| Operating Range | Temperature: -40°C to 70°C (-40°F to 158°F) Humidity: 0 to 100% RH |
| Standards Compliance | CE, IP68, FCC, CE, RoHS |
| Environment | Primarily Designed for Outdoor Usage |
| Wetted Materials | 316 Stainless Steel Housing; Viton® O-rings; Acetyl Cap, Ceramic Sensor |
| Weight | 210 grams (7.4 oz) |
| Dimensions | 2.46 cm (Diameter) x 15.0 (Length)(1.25" x 6.0") Mounting Hole: 6.3 mm (0.25") Diameter |
