Onset HOBO MX800 Series Water Data Loggers
Features
- Submersible and direct read options available
- Wireless data offload via Bluetooth 5.0 and HOBOconnect mobile app
- Water detect feature indicates when logger was out of the water
- Free ground shipping
- Expedited repair and warranty service
- Lifetime technical support
- More
Overview
HOBO MX800 Series wireless data loggers work with interchangeable sensors to provide a highly configurable solution for monitoring water conductivity/salinity, temperature, level, and dissolved oxygen. Available in both an easy-to-deploy, fully submersible model (MX801) and a direct read model (MX802) for convenient data offload that doesn’t require having to remove sensors from the water.
Features
- Compatible with interchangeable Conductivity, CTD (conductivity/temperature/depth), and DO sensors (sold separately) - swap out sensors for different applications
- Bluetooth, for easy logger configuration and data offload
- Easy to deploy, fully submersible (MX801)
- Direct read for convenient data offload (MX802)
- Logger diameter is less than 2 inches
- Faster data offload via Bluetooth 5.0
- Water detect feature indicates when logger was out of the water (MX801)
- Barometric pressure sensor included (MX802)
- Connect two sensors to one logger to get measurements like salinity adjusted DO directly, with no need for post processing
- Guided calibration ensures accurate data
- User-replaceable batteries
MX801 and MX802 | |
Operating Range | -40° to 50°C (-40° to 122°F), cannot be frozen in ice |
Radio Power | 1 mW (0 dBm) |
Transmission Range | Approximately 30.5 m (100 ft) line-of-sight |
Wireless Data Standard | Bluetooth 5 |
Maximum Number of Sensors | 2 |
Maximum Cable Length | 120m (400 ft) |
Logging Rate | 5 second to 18 hours |
Logging Modes | Fixed interval (normal or statistics), burst, or multiple intervals with up to 8 user-defined logging intervals and durations, with pause and repeat options |
Start Modes | Immediate, next interval or date & time |
Stop Modes | Memory full, never stop (overwrite oldest data), date & time, or after a set logging period |
Water Detect | Events are logged when logger is submerged or removed from the water (MX801 only) |
Time Accuracy | ±1 minute per month 0° to 50°C (32° to 122°F) |
Battery | Four AA, 1.5 V lithium batteries, user replaceable |
Battery Life | With W-CTD or W-CT sensors: 2 years, typical with 1-minute logging interval or slower |
With W-DO sensor: 1-year, typical with 5-minute logging interval or slower | |
Faster logging or statistics sampling intervals, entering burst logging mode, excessive readouts, and remaining connected with the app will impact battery life | |
Memory | 730,000 measurements, divided between channels (4 Mbyte memory) |
Data Download Time (Bluetooth 5) | Full memory: Approximately 3.5 minutes |
120,000 measurements: 1 minute | |
May take longer the further the device is from the logger | |
Dimensions | Logger diameter: 4.14 cm (1.63 inches) |
Length without sensor: 20 cm (8 inches) | |
Length with W-CTD sensor: 36 cm (14 inches) | |
Length with W-CT sensor: 33 cm (13 inches) | |
Mounting loop: 12.7 x 22.6 mm (0.5 x 0.89 inches) | |
Weight | Approximately xx g (xx oz) in air; approximately xx g (xx oz) in saltwater |
Wetted Materials | Logger: PVC housing with polyester film label, PET sensor connector end cap and mounting handle with EPDM and Buna-N O-rings, passivated 316 stainless steel hardware rated for use in saltwater; MX802 also has ePTFE vent |
Collar: HDPE, titanium screws | |
Note: logger should be mounted so that no metal parts of the logger are in contact with other metals | |
Environmental Rating | MX801: IP68; waterproof to 100m (with sensor(s) attached) |
MX802: IP67, NEMA 6; Weatherproof (with cable or Termination Plug attached); this model is not waterproof | |
MX802 Barometric Pressure | |
Measurement & Calibrated Range | 66 to 107 kPa (9.6 to 15.5 psia), -20° to 50°C (-4° to 122°F) |
Accuracy* | Typical error: ±0.2 kPa (0.029 psi) |
Maximum error: ±0.5 kPa (0.073 psi) | |
Resolution | <0.01 kPa (0.0015 psi) |
Pressure Response Time** | <1 second to 90% at a stable temperature |
Contribution to Water Level Accuracy*** | Typical error: ±0.075% FS, 0.3 cm (0.01 ft) water |
Maximum error: ±0.15% FS, 0.6 cm (0.02 ft) water | |
*Pressure Accuracy: Absolute pressure sensor accuracy includes all sensor drift, temperature, and hysteresis-induced errors. | |
**Changes in Temperature: Allow 20 minutes in water to achieve full temperature compensation of the pressure sensor. There can be up to 0.5% of additional error due to rapid temperature changes. | |
***Water Level Accuracy: With accurate reference water level measurement, known for water density, and a stable temperature environment. System Water Level Accuracy equals the sum of the Barometric Water Level Accuracy plus the selected CTD sensor Water Level Accuracy. |
- (1) HOBO MX800 data logger
- (1) Coupler
- (1) 3/32" Allen wrench
In The News
Monitoring Hurricanes and Predicting Flooding in the Age of Climate Change
Still recovering from Hurricane Helene, which caused extreme precipitation, flooding, landslides, and other environmental disasters associated with severe weather, the southeastern part of the U.S. is predicted to be hit by another storm, Hurricane Milton. 
 
With Hurricane Helene having made landfall only a little over a week ago on September 27 th , many communities are still recovering. ABC reports that over 230 people have been killed as a result of flooding and destruction caused by Helene, with many still missing. 
 
Residents in these heavily impacted states, such as Florida, Georgia, South Carolina, North Carolina, Virginia and Tennessee, are still searching through the rubble of homes, urban centers, and hospitals for loved ones and belongings.
Read MoreFall 2024 Environmental Monitor Available Now
In the Fall 2024 edition of the Environmental Monitor, we highlight resource managers and researchers who work together to protect and preserve natural resources. From monitoring above and below dams to studying harmful algal bloom dynamics in local water bodies, this latest edition highlights the role of environmental data-informed resource management. 
 
Featuring stories from glaciologists to managers of multi-site resource monitoring programs throughout the United States, our writers sought out environmental professionals dedicated to understanding environmental resources and the stressors that threaten them, using data to inform policies, restoration, and various initiatives. 
 
If you don’t have a subscription, you can sign up for free .
Read MoreReintroducing Historically Native Fish in America’s Largest Wilderness
Among the dozens of publicly protected national parks, hundreds of wilderness areas, and thousands of state parks in the contiguous U.S., none are larger than the Adirondack Park, a 6 million-acre wilderness area that spreads across upstate New York. 
 
 With 3,000 lakes and ponds and 30,000 miles of rivers and streams, the waterways of the Adirondacks are enormous. Diverse aquatic habitats and ecosystems abound, along with bountiful recreational opportunities. 
 
 Nearly half of this land is owned by the state of New York and managed through the New York State Department of Environmental Conservation (DEC) as a forest preserve to return the wilderness to its “presettlement” state.
Read More