Environmental
|
LI-193 Spherical Quantum SensorUnderwater PAR From All Directions
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.
Absolute Calibration: ± 5% in air traceable to NIST. Sensitivity: Typically 7 µA per 1000 µmol s-1 m-2 in water. Linearity: Maximum deviation of 1% up to 10,000 µmol s-1 m-2. Stability: < ± 2% change over a 1 year period. Response Time: 10 µS. Temperature Dependence: ± 0.15% per °C maximum. Angular Response: < ± 4% error up to ± 90° from normal axis (see Angular Response chart). Azimuth: < ± 3% error over 360° at 90° from normal axis. Detector: High stability silicon photovoltaic detector (blue enhanced). Sensor Housing: Corrosion resistant metal for both saltwater and freshwater applications with an injection molded, impact resistant, acrylic diffuser. Units have been tested to 500 psi (3400 kPa, 350 meters) with no failures. Size Globe: 6.1 cm Dia. (2.4”). Weight: 142 g (0.31 lbs.). Mounting: Three 6-32 mounting holes are tapped into the base for use with the 2009S Lowering Frame or other mounting devices. Cable: Requires 2222UWB Underwater Cable. Underwater Sensors can be purchased with several accessories. Please see Accessories Page for details. The LI-193SA must be used in combination with a 2222UWB Underwater Cable. This combination can be directly connected to the LI-250A Light Meter or LI-1400 Data Logger. The 2291 Millivolt Adapter should be ordered if the LI-193SA will be used with a data acquisition device or data logger that measures millivolts. The 2291 uses a 1210 Ohm precision resistor to convert the LI-193SA output from microamps to millivolts. LI-193SA Spherical Quantum Sensor 2009S Lowering Frame 2291 Millivolt Adapter 2222UWB-3 Underwater Cable, 3 meters 2222UWB-10 Underwater Cable, 10 meters 2222UWB-30 Underwater Cable, 30 meters 2222UWB-50 Underwater Cable, 50 meters 2222UWB-100 Underwater Cable, 100 meters 100L Lubricant
Additional literature related to the LI-193 is also available:
If you have any questions about the LI-193 please feel free to contact us and discuss with our Applications Analysts and Scientists (or your local LI-COR Distributor) how the LI-193 can help you with your research. Selected Links
Please submit your published papers or links to your websites to be featured here by contacting the Product Manager, Mr. Brent Claassen. Journal ReferencesUse the academic search engines below to find references to the LI-193 in many peer reviewed scientific publications. For best results, start with the search terms provided below or use the forms to customize a search. Results open in a new window. References from HighWire Press - Internet Imprint of the Stanford University Libraries
References from Google Scholar™Common Internet searches can be performed with Google, and many articles can be found with Google Scholar: The LI-193 includes a printed copy of the Instruction Manual. You can download future updates of the LI-193 manual on this page.
|
|||||||||
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 utilize
radiation from all directions for photosynthesis.
