亮度的計算教學(xué)課件

1、發(fā)光器件的測量,NRC INMS PAR Measurement Course Web Instruments,光度學(xué)和輻射度學(xué)的基本概念,A 輻射能通量（輻射功率，單位：瓦 W） 輻射能通量的譜密度,輻射能通量的譜密度：,視見函數(shù),定義：,當(dāng)= 555 nm 時，V=1,實驗表明：,= 400 nm,a 光通量,光源發(fā)出的輻射能通量通過視見函 數(shù)的權(quán)重因子折合成對人眼起作用 的有效視覺強(qiáng)度稱為光通量。 單位：流明 lm,有：,或者：,最大光功當(dāng)量，,1 lumen = 1/683 W at 555 nm,From a quantum mechanic perspective of photo

2、n flow rate and photon energy (E) at 555 nm,This is what 1 lumen is equivalent to.,b 發(fā)光強(qiáng)度 和 B 輻射強(qiáng)度,點光源發(fā)光強(qiáng)度,Radiometric Intensity is the radiometric flux density (watts) per steradian (W/sr),Photometric (luminous) intensity is the luminous flux density per steradian expressed in candellas.,Exponentia

3、l Intensity Source: profiles radiation patterns of LEDs, both wide and and narrow beam widths.,Where n is the radiation exponent,c 亮度和 C 輻射亮度,亮度：,輻射亮度：,d 照度和 D 輻射照度,(光)照度定義：,，,單位：lux, lx,輻射照度定義：,單位：W/m2,watts per square meter,，,點光源的照度,，,面光源的照度,注意： （a）通常情況下光強(qiáng)的概念與這里的輻射 照度的概念一致，單位是W/cm2 。 （b）照度是接收的概念，發(fā)

4、光強(qiáng)度 和亮度是發(fā)射的概念。,Some Typical Luminance And Radiance Levels,視見函數(shù),400,500,600,700,800,0,1,1.8,Wavelength, nm,Photopic Sensitivity,y,This curve shows the relative sensitivity of the eye. To convert to photometric units from radiometric, multiply by 683 Lumens Per Watt,Color: Tristimulus Values,Describe

5、Eyes Response to Color Based on Color Matching Experiments Small Number of Observers Lines are Approximations,Spectral radiance Le(), the usual units are Watt/steradian/m2/nm,PR-705,Radiance(watts/sr/m2) 3802.846e-003 3821.285e-002 3842.987e-002 3863.336e-002 3881.459e-002 3901.739e-002 3921.675e-00

6、2 3944.251e-003 3961.720e-002 3982.580e-002 4002.076e-002 4025.027e-003 4041.362e-002 4063.447e-002 4083.644e-002 4105.342e-002 4128.716e-002 4141.359e-001 4161.861e-001 4182.458e-001 4203.686e-001,Photometry Observer: 2 degrees Luminance(cd/m2)8.138e+004 Luminance(fl) 2.375e+004 Scotopic Y(cd/m2)9.

7、670e+004 Scotopic Y(fl) 7.025e+004 Pho. Transmit. (%)N/A Pho. Reflect. (%)N/A Pho. Opt. DensityN/A Pho. AbsorptanceN/A Observer: 10 degrees Luminance(cd/m2)9.088e+004 Luminance(fl) 2.652e+004 Pho. Transmit. (%)N/A Pho. Reflect. (%)N/A Pho. Opt. DensityN/A Pho. AbsorptanceN/A,Radiometry Radiance(watt

8、s/sr/m2) 3.393e+002 Photon Rad.(photons/sr/m2/sec) 8.782e+020 Rad. Transmit. (%) N/A Rad. Reflect (%) N/A Rad. Opt. Density N/A Rad. Absorptance N/A,Chromaticity Observer: 2 degrees X 9.101e+004 Y 8.138e+004 Z 1.832e+005 CCT 91020 MK -1 11.0 u-v Dev -0.0153 x 0.2559 y 0.2289 u 0.1956 v 0.2623 u 0.19

9、56 v 0.3935 Observer: 10 degrees,Avantes 光纖光譜儀 一個光子的能量： E = hc/ （J） 其中 h = Plancks constant (6.626 10-34 Js) c = Speed of light (2.998108 ms-1) = Wavelength (m) 一個焦耳的光子數(shù) the number of photons per joule is: （in nm）5.0341015 1 mol = 6.023081023 (Number of Avogadro) 1 mol = 6.023081017,單位換算 1 Watt/cm2

10、= 1 Joule/s/cm2 = 0.01 Joule/s/m2 0.01(nm)5.0341015/6.02308/1017 Mol/(sm2) =(nm)0.0000835785 Mol/(sm2) The photon count distribution Mol/(sm2nm) shows the photon flux received per square meter. Other photon count units that can be calculated from this are: Mol/(snm) photon flux received at diffuser surface Mol/( m2nm) photons received per square meter during one integration cycle Mol/nm photons received at diffuser surface during one integration cycle Illuminance曲線 lm/m2或lux =測量的Irradiance曲線 Watt/cm2 0.01683視見函數(shù) Photometry 文