Weber (unit) weber), could equally serve as the fourth fundamental unit. "After consultation, the ampere was adopted as the fourth unit of the Giorgi system in Paris in 1950." Weber (unit) In physics, the weber (symbol: Wb) is the SI unit of magnetic flux. A "flux density" of one Wb/m (one weber per square metre) is one tesla. The weber is named after the German physicist Wilhelm Eduard Weber (1804–1891). The weber may be defined in terms of Faraday's law, which relates a changing magnetic flux through a loop to the electric field around the loop. A change in flux of one
Spectral flux density 1 MW m), W·m·Hz, Jansky or solar flux units. The terms irradiance, radiant exitance, radiant emittance, and radiosity are closely related to spectral flux density. The terms used to describe spectral flux density vary between fields, sometimes including adjectives such as "electromagnetic" or "radiative", and sometimes dropping the word "density". Applications include: For the flux density received from a remote unresolvable "point source", the measuring instrument, usually telescopic, though not able to resolve any detail of the source itself, must be able to optically resolve enough details of the sky around the point source, so as to record radiation coming