OverviewUnderwater PAR From All Directions
The LI-193 Underwater Spherical Quantum Sensor gives an added dimension to underwater PAR measurements as it measures photon flux from all directions. This measurement is referred to as Photosynthetic Photon Flux Fluence Rate (PPFFR) or Quantum Scalar Irradiance. This is important, for example, when studying phytoplankton, which utilise radiation from all directions for photosynthesis.
The LI-193 features a high sensitivity optical design and compact, rugged construction (3400 kPa, 350 meters depth, 3400 kPa = 493 psi).
The graph at right indicates the typical angular response of the LI-193 Spherical Quantum Sensor. The low response on the bottom of the sensor is due to light blockage by the detector housing. The error due to this low response is not significant in most cases because of the small portion of upwelling radiation compared to the total radiation.
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Features
Sensor lead terminates with a BNC connector for use with a LI-COR light meter or data logger. Sensor delivers a microamp current output.
Type SA sensors can be used with non-LI-COR devices requiring a millivolt signal, with the use of the appropriate Millivolt Adapter. This adapter mates with the sensor’s BNC connector and terminates in bare wires. Resulting output is in millivolts, and is proportional to the sensitivity of the sensor to which it is connected.
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