Onset HOBO MX Temp/RH Logger
Features
- Stores 84,000 measurements
- Easy to deploy and offload using the free HOBOconnect app
- Visual and audible high & low alarm thresholds
- Expedited repair and warranty service
- Lifetime technical support
- More
Overview
The Onset HOBO MX1101 data logger measures and transmits temperature and relative humidity data wirelessly to mobile devices or Windows computers via Bluetooth Low Energy (BLE) technology. Add the MX Gateway for remote access to data in Onset's cloud-based HOBOlink software.
Mechanics
The self-contained wireless data logger works with a mobile device or Windows computer and Onset's free HOBOconnect app so users can configure the logger and read out data over a 100-foot range, with no other dedicated equipment required. Using Onset's free app, users can also view data in graphs, check the operational status of loggers, configure alarm notifications, and share data files.
Temperature Sensor | |
Range | -20° to 70°C (-4° to 158°F) |
Accuracy | ±0.21°C from 0° to 50°C (±0.38°F from 32° to 122°F) |
Resolution | 0.024°C at 25°C (0.04°F at 77°F) |
Drift | <0.1°C (0.18°F) per year |
RH Sensor* | |
Range | 1% to 90%, non-condensing |
Accuracy | ±2.0% from 20% RH to 80% RH typical to a maximum of ±4.5% including hysteresis at 25˚C (77˚F); below 20% RH and above 80% RH ±6% typical |
Resolution | 0.01% |
Drift | <1% per year typical |
Response Time | |
Temperature | 7:30 minutes in air moving 1 m/s (2.2 mph) |
RH | 20 seconds to 90% in airflow of 1 m/s (2.2 mph) |
Logger | |
Radio Power | 1 mW (0 dBm) |
Transmission Range | Approximately 30.5 m (100 ft) line-of-sight |
Wireless Data Standard | Bluetooth Smart (Bluetooth Low Energy, Bluetooth 4.0) |
Logger Operating Range | -20° to 70°C (-4° to 158°F); 0 to 95% RH (non-condensing) |
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 |
Restart Mode | Push button |
Time Accuracy | ±1 minute per month at 25°C (77°F) |
Battery Life | 1 year, typical with logging interval of 1 minute. Faster logging and/or statistics sampling intervals, entering burst logging mode, and remaining connected with the app will impact battery life. Excessive readouts, audible alarms, and paging all impact battery life. Visual alarms and other events can have a marginal impact on battery life. |
Battery Type | Two AAA 1.5 V alkaline batteries, user replaceable |
Memory | 128 KB (84,650 measurements, maximum) |
Full Memory Download Time | Approximately 60 seconds; may take longer the further the device is from the logger |
LCD | LCD is visible from 0° to 50°C (32° to 122°F); the LCD may react slowly or go blank in temperatures outside this range |
Size | 3.66 x 8.48 x 2.29 cm (1.44 x 3.34 x 0.9 in.) |
Weight | 56 g (1.98 oz) |
Environmental Rating | IP50 |
- HOBO MX1101 Temp/RH Data Logger
- Command strip
- Double-sided tape
- Hook & loop strap
- Two AAA 1.5 V alkaline batteries
In The News
Cal Poly, San Luis Obispo Manages Monitoring Efforts in Morro Bay
California Polytechnic State University, San Luis Obispo (Cal Poly, SLO), has been monitoring Morro Bay for decades, and while the monitoring program has changed over the years, the dedication to monitoring the bay has remained the same. 
 
The project started in 2006 as a Packard Foundation-funded initiative to monitor water quality flowing in and out of Morro Bay. The goal at the time was to use the data collected to develop and inform an ecosystem-based management plan in collaboration with the Morro Bay National Estuary Program (MBNEP). 
 
Since the estuary was the focus at the time, researchers were monitoring water flowing into the estuary from Chorro Creek and Los Osos Creek.
Read MoreGreen Water in Green Bay: Using Data Buoys to Monitor the Southern Bay
While the bay of Green Bay has been referred to as the largest freshwater “estuary” in the world, the watershed hosts intensive agriculture and contributes one-third of Lake Michigan’s total phosphorus load. 
 
 The Fox River flows into the bay, carrying excess nutrients largely the result of non-point source runoff from the watershed. With a history of deterioration extending well into the last century, the bay ecosystem suffered significant declines in water quality. 
 
 This, in turn, stimulated major clean-up and ongoing restoration efforts to improve water quality. Tracking these changes is an important aspect of ecosystem management.
Read MoreCross-Border Sewage Contaminated Flows: Monitoring the Tijuana River
The Tijuana River runs across the US-Mexico boundary, flowing into and throughout southern California, carrying with it nutrients and contaminants throughout the estuary. In recent decades, the flows have been heavily polluted with untreated sewage from the City of Tijuana. 
 
The wastewater enters the greater Tijuana River estuary, impacting coastal communities and disrupting the natural environment. In order to better understand these cross-border flows, researchers out of San Diego University sought to monitor the waterway test the capabilities of in-situ sensors to measure the contaminated water. 
 
Natalie Mladenov and Trent Biggs were two of the researchers involved in the project, deploying a real-time monitoring system in May of 2021.
Read More