Up for sale is one or more Li-Cor Line Quantum Sensor, model LI-191SA. These devices measures PAR Integrated over the 1-meter length - watch video showing the entire rod sensing ambient light and also sensing a flashlight at random locations along the length of the sensor. Perfect for areas with moving or inconsistent light.  All are sensitive to light. We tested all with our trusty LI-185B Quantum/Radiometer/Photometer with LI-193SB Spherical Quantum Sensor attachment and a simple coax cable with BNC connectors at both ends (not included, but listed for sale here on ebay). These are ready to use.

Li-Cor states that these are the same as the Li-Cor LI191R. The only difference is the BNC connector on the LI-191SA has a plastic isolation base and the LI-191R has a stronger metal flange. Light measuring performance is the same.

Three have glue in the mounting channel that has no affect on performance. Message me during checkout if these are not acceptable other wise I will ship highest serial number first.

Buy more than 3 and I'll ship in a Li-Cor case (see last photo of case). 

Specs from Li-Cor

LI-191R
Line Quantum Sensor

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

Why choose the LI-191R

  • Improved water resistance for long-term outdoor deployment
  • Integrated measurements using a single detector prevents variance found in sensors that use multiple detectors
  • Selected by the National Ecological Observatory Network (NEON®) for integrated PAR measurements

  • How does it work?

    The LI-191R uses a 1-meter long quartz rod under a diffuser to direct light to a single filtered silicon photodiode. 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. 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. The unique design of the LI-191R provides an excellent quantum response that is close to the ideal quantum response.

LI-191R Specifications

  • Absolute Calibration: ± 10% traceable to National Institute of Science and Technology (NIST). The LI-191 is calibrated via transfer calibration using a reference LI-190R Quantum Sensor. Transfer error is ± 5% (included in the ± 10%)
  • 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
  • Operating Temperature Range: −40 °C to 65 °C
  • Relative Humidity Range: 0% to 95% RH, Non-Condensing
  • 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: 3.1 m (10.0 ft.)