The LI190R Quantum Sensor, manufactured by LI-COR, accurately measures photosynthetic photon flux density (PPFD), which is the number of photons in the 400 to 700 nm waveband incident per unit time on a unit surface. It uses a silicon photovoltaic detector mounted in a cosine-corrected head. A shunt resistor in the sensor’s cable converts the signal from microamps to millivolts, allowing these sensors to be measured directly by a Campbell Scientific datalogger.
The "-L" on a product model indicates that the cable length is specified at the time of order.
The LI190R measures solar radiation with a silicon photovoltaic detector mounted in a cosine-corrected head. A shunt resistor in the sensor’s cable converts the signal from microamps to millivolts, allowing the LI190R to be measured directly by a Campbell Scientific datalogger. The LI190R accurately measures Photosynthetic Photon Flux Density (PPFD), which is the number of photons in the 400 to 700 nm waveband incident per unit time on a unit surface. Because PPFD describes photosynthetic activity, the LI190R is ideal for growth chambers and greenhouses.
|Light Spectrum Waveband||400 to 700 nm|
|Calibration||±5% traceable to the U.S. National Institute of Standards Technology (NIST)|
|Sensitivity Range||Typically 5 to 10 μA per 1000 μmoles s-1 m-2|
|Linearity||Maximum deviation of 1% (up to 10,000 μmole s-1 m-2)|
|Shunt Resistor||604 Ω, 0.1%, 25 ppm|
|Long-Term Stability||< ±2% change over a 1 year period|
|Response Time||< 1 μs|
|Temperature Dependence||0.15% per °C (maximum)|
|Cosine Correction||Cosine corrected up to 82° angle of incidence|
|Operating Temperature Range||-40° to +65°C|
|Relative Humidity Range||0 to 100% (non-condensing)|
|Detector Description||High-stability silicon photovoltaic (blue enhanced)|
|Sensor Housing Description||Weatherproof anodized aluminum case with acrylic diffuser and stainless-steel hardware; O-ring seal on the removable base and cable assembly|
|Diameter||2.36 cm (0.93 in.)|
|Height||3.63 cm (1.43 in.)|
|Weight||84 g (2.96 oz)|
Note: The following shows notable compatibility information. It is not a comprehensive list of all compatible or incompatible products.
To ensure accurate measurements, the sensor should be leveled using an LI2003S leveling fixture, which incorporates a bubble level and three adjusting screws. The LI2003S leveling fixture mounts to a tripod using the 015ARM or to a crossarm using the CM225 mount. These sensors should be mounted away from all obstructions and reflective surfaces that might adversely affect the measurement.
The LI190R-L requires one differential analog input channel per probe.