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Powerful Tools That Illuminate Your Insights
Accurate data and a deeper understanding of how light impacts your application can produce powerful insights and unlock innovative solutions. From commercial greenhouses and urban farms to building efficiency or stream ecological studies, measuring variables like solar radiation, light intensity, photosynthetically active radiation (PAR), spectral composition, and more can help you identify ways to optimize your operations, ideate solutions, and inform your decisions. Easy-to-use, affordable, and highly accurate, HOBO and LI-COR light monitoring sensors and connected IoT solutions like scalable HOBOnet sensor networks will amplify your efforts...and results.
A Spectrum of Light Sensor Options
Reliable and highly accurate, these industry-leading sensors are easy to use and seamlessly integrate into your existing monitoring deployments. Plus, our analog input options let you integrate other popular and preferred third party sensors!
PAR Data Loggers for Agricultural and Underwater Environments
Photosynthetically Active Radiation (PAR) Sensors
Sensor
LI-COR LI-190R Quantum Sensor, Bare Lead
This industry-leading PAR sensor from LI-COR Environmental integrates with the HOBOnet sensor network's Analog Module to provide highly precise measurements of most broad-spectrum light sources, including natural sunlight, artificial, and mixed.
Data Logger
HOBO MX Underwater PAR Data Logger
Delivers highest-accuracy measurements of photosynthetically active radiation (PAR), temperature, and tilt for both underwater and above water environments.
Sensor
HOBOnet PAR Sensor
A wireless sensor that measures light intensity for frequencies relevant to photosynthesis; communicates data to the HOBO RX3000 or the HOBO MicroRX station; preconfigured and ready to deploy.
Sensor
Photosynthetic Light (PAR) Smart Sensor
Measures light intensity for frequencies relevant for photosynthesis; measurement range of 0 to 2500 umol/m2/sec over wavelengths from 400 to 700 nm.
Global Solar Radiation Sensors
Sensor
LI-COR LI-200R Pyranometer, Bare Leads
Measures global solar radiation in watts per square meter (W m-2) for various research applications.
Sensor
HOBOnet Solar Radiation (Silicon Pyranometer) Sensor
Wirelessly measures light intensity for frequencies relevant to solar radiation; communicates data to the HOBO RX3000 or the HOBO MicroRX station; preconfigured and ready to deploy.
Sensor
Solar Radiation (Silicon Pyranometer) Smart Sensor
Measures light levels; rapid deployment, with no complicated programming or setup required; compatible with H21, H22, and U30 family loggers
Looking for Indoor Light Monitoring?
HOBO offers easy-to-deploy data loggers to measure light use and intensity.
See Indoor Light Monitoring Data Loggers
Connect your sensors to a remote monitoring network
Amplify your monitoring by connecting your chosen sensors to a HOBOnet sensor network, which automatically sends measurements data straight to LI-COR Cloud monitoring software via an RX cellular station.
How do you measure light?
Radiation sensors measure the flux of radiant energy—the energy that drives plant growth, warms the earth, and lights our world. The properties of radiant flux depend on the wavelength of the radiation.
Light Sensor Design
LI-COR sensors are weather resistant, low maintenance, and cosine corrected. From the shape of the crown to the photodiodes and optical filter glass, every aspect is the result of scientific inquiry.
Frequently Asked Questions (FAQ)
FAQs
HOBO and LI-COR offer three main types of light measurement:
- PAR (Photosynthetically Active Radiation) — measures light in the 400–700 nm waveband used by plants for photosynthesis; measured in µmol/m²/s
- Solar Radiation (Pyranometer) — measures total global solar radiation across a broader waveband; measured in W/m²
- Underwater PAR — measures PAR below the water surface for aquatic plant and coral reef research
- HOBO also offers Indoor light monitoring devices for assessing occupancy/light use and light intensity
- A PAR (quantum) sensor measures light in the 400–700 nm waveband — the specific range used by plants for photosynthesis. It is the correct measurement for crop growth, greenhouse management, and aquatic ecology studies.
- A pyranometer measures a broader waveband of solar radiation (typically 300–2800 nm), making it the right choice for solar energy site assessment, weather monitoring, and ET calculations. They are not interchangeable for research-grade applications.
Daily Light Integral (DLI) is the total amount of PAR light received by a plant over a full day, measured in mol/m²/day. DLI is one of the most important metrics for greenhouse and indoor farm management — different crops have optimal DLI thresholds for flowering, yield, and quality. The HOBO MX2308 Bluetooth logger measures PAR, temperature, humidity, DLI, and VPD (vapor pressure deficit) together from one device, making it ideal for greenhouse monitoring.
Yes. The HOBO MX2502 Underwater PAR Data Logger is specifically designed for submerged environments, delivering research-grade PAR, temperature, and tilt measurements using a waterproof LI-COR quantum sensor. It supports Bluetooth wireless data offload and is used for aquatic ecology, coral reef research, water quality studies, and underwater light attenuation monitoring. It operates in both above-water and underwater environments.
LI-COR PAR (LI-190R) and pyranometer (LI-200R) sensors connect to HOBOnet systems and RX stations via analog input adapters — either the wired Analog Module (RXMOD-A1) or the wireless Analog Mote (RXW-ANA). The LI-COR sensors come with bare leads and require a 2420 Amplifier to interface with either analog device. The Analog Mote also requires a HOBOnet Manager to receive the Mote's signal at the station. Alternatively, HOBO's own HOBOnet PAR sensor (RXW-LIA) and Solar Radiation sensor (RXW-LIB) are pre-configured wireless sensors ready to deploy directly into HOBOnet networks.
HOBO light monitoring is used across a wide range of applications:
- Agriculture and horticulture — optimizing crop light exposure, DLI management in greenhouses and vertical farms
- Aquatic ecology — monitoring underwater light availability for seagrass, coral, and phytoplankton
- Solar energy — site evaluation for photovoltaic installation using pyranometer data
- Building efficiency — tracking daylighting and shading impacts on HVAC loads
- Climate and weather research — solar radiation as a key input for ET, energy balance, and climate models
Pyranometers are sensitive to the broadest waveband. Photometric sensors measure visible radiation (light). Quantum sensors measure Photosynthetically Active Radiation (PAR)—the radiant energy used in photosynthesis.