Table of Contents
Radiation and Photometry
Radiometry: The science of radiation measurement.
Terms and Units
Radiant flux density: Rate of transfer of energy per unit time per unit area from an emitting object or onto a receiving object. In meteorology, it is used as a expression of the thermal effect due to radiation. Units: W/m2
Conversion of units:
Luminous Flux
Green light (of the same wattage) appears brighter than blue light.
Illuminance: Luminous flux incident on a unit surface area.
Terms
Radiation Instrument Standards
Radiation Sensors
Temperature (thermal) sensors
Photoelectric Transducer Sensors
When the n-type and p-type are placed together, free electrons on the n-side, rush to the p-side, leaving holes on the n-side.
Eventually, equilibrium is reached and an electric field near the junction separates the two sides. This field acts as a diode, allowing electrons to flow from the p-side to the n-side, but not the other direction.
An external current path then allows the electron to flow back to its original side, doing work as it does so, to unite with the electron hole.
Photoconductive transducers
External Photoelectric Effect
Photochemical Devices
Radiation Instruments
Pyrradiometer - Global radiation (short and longwave) from a hemispheric sky.
Pyrheliometers
An instrument with a fixed limiting aperture will received radiation from different percentages of the Sunís disc throughout the year.
R = radius of limiting aperture
Pyrheliometers
PPT Slide
PPT Slide
Angstrom Compensation Pyrheliometer
PPT Slide
Pyranometers
Eppley Precision Spectral Pyranometer
Gunn-Bellani Pyranometer (Integrator)
Robitzsch Bimetallic Pyranometer (Pyranograph)
Shadow Bands
Pyrgeometers
Pyrradiometers
Radiation Duration measuring Instruments
Meteorological Visibility
Meteorological Optical Range
Photometry
PPT Slide
Xenon Spark Lamp
ASOS Visibility Sensor
PPT Slide
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