LI-COR LI-191R Line PAR Sensors

The LI-COR LI-191R Line PAR Sensor measures photosynthetically active radiation (PAR) over its one meter length for use within a plant canopy.

Features

  • Spatially averages PPFD over its 1m length
  • Uses a 1m quartz rod under a diffuser to conduct light to a single Quantum sensor
  • Improved water resistance for long-term outdoor deployment
List Price $$$$$
Your Price Check Price
Usually ships in 3-5 days
LI-COR
Free Lifetime Tech SupportFree Lifetime Tech Support
Free Ground ShippingFree Ground Shipping
ImagePart#Product DescriptionPriceStockOrder
LI-COR LI-191R Line PAR SensorsLI-191R-BNC-2 Line Quantum sensor with microamp output, 2m cable with BNC connector
Check Price
Usually ships in 3-5 days
LI-COR LI-191R Line PAR Sensors LI-191R-BNC-5 Line Quantum sensor with microamp output, 5m cable with BNC connector
Check Price
Usually ships in 3-5 days
LI-COR LI-191R Line PAR Sensors LI-191R-SMV-2 Line Quantum sensor with standardized mV output, 2m cable with bare leads
Check Price
Usually ships in 3-5 days
LI-COR LI-191R Line PAR Sensors LI-191R-SMV-5 Line Quantum sensor with standardized mV output, 5m cable with bare leads
Check Price
Usually ships in 3-5 days
ImagePart#Product DescriptionPriceStockOrder
LI-COR Sensor Extension Cables 2222SB Extension cable, for use with type BNC or SMV terrestrial light sensors, 15m
Check Price
Usually ships in 3-5 days
LI-COR 100 ft. Sensor Extension Cable 2222SB-100 Extension cable, for use with type BNC or SMV terrestrial light sensors, 30m
Check Price
Usually ships in 3-5 days
LI-COR BNC to Bare Lead Adapter 2200 BNC to bare lead adapter, converts BNC type sensors to BL type sensors
Check Price
In Stock
LI-COR Sensor Millivolt Adapters 2290 Sensor millivolt adapter (604 Ohm resistor), for use with LI-190R-BNC, LI-191R-BNC & LI-210R-BNC sensors
Check Price
Usually ships in 3-5 days
LI-COR 2420 Light Sensor Amplifier 2420-BNC Light sensor amplifier, BNC connector
Check Price
Usually ships in 3-5 days
LI-COR LI-250A Light Meter LI-250A Light meter
Check Price
In Stock
LI-COR LI-1500 Light Sensor Logger LI-1500 Light sensor logger
Check Price
Usually ships in 3-5 days
LI-COR LI-1500 Light Sensor Logger LI-1500G Light sensor logger with GPS
Check Price
Usually ships in 3-5 days

The LI-191R Line Quantum Sensor measures Photosynthetically Active Radiation (PAR) integrated over its 1-meter length. It is used to measure sunlight under a plant canopy, where the light field is non-uniform. It measures light in units of Photosynthetic Photon Flux Density (PPFD), which is expressed as μmol s-1 m-2.

A non-uniform light field under a plant canopy is difficult to characterize with a single sensor or multiple sensors arranged in a line because the light field can vary considerably from point to point and over a line.

To solve this problem, the entire LI‑191R diffuser is sensitive to light over its 1-meter length. Since the diffuser is one continuous piece, the LI‑191R essentially integrates an infinite number of points over its surface into a single value that represents light from the entire 1-meter length.

Sensors that use multiple photodiodes potentially induce large uncertainty in measurements because each photodiode can drift independently of the others. The diffuser and single photodiode in the LI‑191R provide stable, integrated measurements that are superior to averages provided by many linear sensors.

Optical filters block radiation with wavelengths beyond 700 nm, which is critical for under-canopy measurements, where the ratio of infrared to visible light may be high.

  • Absolute Calibration: ± 10% traceable to National Institute of Science and Technology (NIST). The LI-191 is calibrated via transfer calibration
  • Sensitivity: Typically 7 μA per 1,000 μmol s-1 m-2
  • Linearity: Maximum deviation of 1% up to 10,000 μmol s-1 m-2
  • Response Time: 10 μs
  • Temperature Dependence: ± 0.15% per °C maximum
  • Cosine Correction: Acrylic diffuser
  • Azimuth: < ± 2% error over 360° at 45° elevation
  • Sensitivity Variation over Length: ± 7% maximum using a 2.54 cm (1”) wide beam from an incandescent light source.
  • Sensing Area: 1 m × 12.7 mm (39.4” × 0.50”)
  • Detector: High stability silicon photovoltaic detector (blue enhanced)
  • Sensor Housing: Weatherproof anodized aluminum housing with acrylic diffuser and stainless steel hardware.
  • Size: 121.3 L × 2.54 W × 2.54 cm D (47.7” × 1.0” × 1.0”)
  • Weight: 1.4 kg (3.0 lbs.)
  • Cable Length: 2 m, 5 m (6.5', 16.4')
  • (1) LI-191R Line PAR Sensor
  • (1) Bubble level
  • (1) Detachable 10 ft. cable
  • (1) Hard-sided carrying case
Questions & Answers
No Questions
Please, mind that only logged in users can submit questions

In The News

A Lesson in Persistence: Taking On Cyanobacteria in Florida

As we hear more and more about algal blooms of different kinds across the United States, teams of scientists are working hard to ensure that they don't become our new normal. One project in Florida is taking a multi-disciplinary approach to the problem—including genetic analysis. The team's work is part of a full-court press in Florida recently, making a serious push to understand what is triggering more frequent blooms. Jose Lopez, Ph.D. , of Nova Southeastern University , the primary investigator on the genetic analysis portion of the project, spoke to EM about the project and his work on it. “This is a very good project,” explains Dr. Lopez. “We're excited about it, and it's a lesson in persistence.” Dr.

Read More

Keeping TABS on the Texas Gulf Coast

From extreme weather such as Hurricane Harvey to spills and other accidents, the Gulf Coast of Texas is no stranger to dangerous situations. This is where the data provided by the Texas Automated Buoy System ( TABS ) comes into the picture. Among the nation's most successful and longest-running coastal ocean-observing systems at the state level, the TABS real-time oceanographic buoy system monitors currents, waves, salinity, winds, and other parameters. Dr. Anthony Knap , director of Geochemical Environmental Research Group (GERG) and a Professor of Oceanography at Texas A&amp;M University, spoke to EM about working with TABS. “TABS has been running now for 24 years,” explains Dr. Knap.

Read More

Watchful Eyes on One of Maine's Crown Jewels: Jordan Pond

Formed by a glacier, Jordan Pond is among Maine's clearest, most beautiful bodies of water. It's also a critical freshwater resource, and watchful eyes are protecting it. EM spoke with Dr. Rachel Fowler, Friends of Acadia's aquatic scientist, about her work monitoring Jordan Pond. A postdoctoral research scientist at the University of Maine, she is a member of a partnership among the National Park Service, the University of Maine Climate Change Institute, and Friends of Acadia that began deploying the Jordan Pond buoy in 2013. Canon provided the initial support for the project. Friends of Acadia is a nonprofit organization that supports different projects in the park.

Read More