irradiance
Incident radiant power
Irradiance is the amount of radiant energy—typically light—falling on a surface, measured as power per unit area.
The term appears most often in physics, solar energy, and lighting contexts: Solar irradiance peaks at midday.
Unlike illuminance, which measures light as perceived by human eyes, irradiance covers the full electromagnetic spectrum.
Radiance from our star
- photovoltaicLight-to-electricity converting
- insolationSolar radiation received
- daylightSun's natural glow
- ultravioletWavelengths shorter than violet
photosynthesis · sunbeam · zenith · atmosphere · sunrise · sunset · latitude · seasonal
Light per unit area
- fluxContinuous change or flow
- emissivityThermal radiation ratio
- reflectanceLight return ratio
- transmittanceFraction not absorbed
albedo · candela · steradian · spectral · photon · wavelength · intensity · blackbody
Device measuring illumination levels
- radiometerRadiant energy measuring device
- sensorInput-detecting device
- calibrationAdjusting for measurement accuracy
- fluxContinuous change or flow
spectral · precision · accuracy · quantum · data · dosimeter
Transferred thermal energy
- infraredHeat-bearing electromagnetic waves
- emissionDischarged substance or act
- absorptionProcess of taking in
- temperatureMeasured heat intensity
thermodynamics · conduction · convection · blackbody · cooling · warming
Structural support member
- collimationMaking light rays parallel
- coherenceLogical internal consistency
- laserConcentrated light device
- lensLight-focusing curved glass
focus · divergence · aperture · illumination · uniformity · distribution · falloff · attenuation
sunlight
Radiance from our star
- photovoltaicLight-to-electricity converting
- insolationSolar radiation received
- daylightSun's natural glow
ultraviolet · photosynthesis · sunbeam · zenith · atmosphere · sunrise · sunset · latitude · seasonal · diffuse
luminance
Light per unit area
- fluxContinuous change or flow
- emissivityThermal radiation ratio
- reflectanceLight return ratio
transmittance · albedo · candela · steradian · spectral · photon · wavelength · intensity · blackbody
photometer
Device measuring illumination levels
- radiometerRadiant energy measuring device
- sensorInput-detecting device
- calibrationAdjusting for measurement accuracy
flux · spectral · precision · accuracy · quantum · data · dosimeter
heat
Transferred thermal energy
- infraredHeat-bearing electromagnetic waves
- emissionDischarged substance or act
- absorptionProcess of taking in
temperature · thermodynamics · conduction · convection · blackbody · cooling · warming
beam
Structural support member
- collimationMaking light rays parallel
- coherenceLogical internal consistency
- laserConcentrated light device
lens · focus · divergence · aperture · illumination · uniformity · distribution · falloff · attenuation · scattering
- lightsunlight, daylight, shine, rays, moonlight
- sunsol, solar, sunlight, sunspots, sunshine
- open oceanopen ocean, twilight zone, midnight zone, surface water, water column
- radiant energyphoton, photons, sunlight, visible light, luminescence
- solar powersolar power, solar panels, photovoltaics, solar heat, inverters
- Radiometryradiometer, fluence, reflectance, transmittance, emissivity