Can illuminance/luminance meters be used to measure transmittance?-speed train" with "main engine+supporting facilities" __复制

    Illuminance meter/luminance meter can measure various parameters such as illuminance/luminance, color temperature(CCT), color rendering index(CRU), irradiance spectrum, and photon flux density of plant lamps(PPFD). However, illuminance/luminance meters that can measure the transmittance of transparent samples are very rare. Here, we will share knowledge on using CL800/CL500/CI800 series illuminance meters to measure the transmittance of glasses.

   Transmittance refers to the ratio of the luminous flux (radiation flux) passing through the measured object to the incident luminous flux (radiation flux). Visible light transmittance is usually the ratio of the luminous flux of visible light with wavelengths between 380-780nm, UVA ultraviolet transmittance is usually the ratio of UVA ultraviolet radiation flux, and infrared IR transmittance is the ratio of the infrared radiation flux with wavelengths exceeding 780nm.

   Common transmittance meters usually use LED light sources or halogen lamps as illumination sources. From the measure results, different illumination sources have a certain impact on the transmittance measure results, usually affecting about 5%. The most ideal lighting source for a transmittance meter is the D65 standard lighting source, which is clearly stated in many standards and literature. The D65 standard lighting source is the average spectrum of sunlight in the northern hemisphere, which is most familiar to people. Therefore, the transmittance measureed under such conditions is very typical and easily accepted. For example, relevant standards such as outdoor glass and UV sunscreen glasses clearly state this. However, the light source commonly used in transmittance meters on the market is far from the D65 standard illumination light source, so their measure results are usually not particularly ideal.

   The CL800/CL500/CI800 series illuminance meter can use outdoor sunlight (as close as possible to the D65 standard lighting source) as the lighting source. Through two measures, it is very convenient to measure the transmittance of glasses and building glass under D65 standard lighting source conditions.

    The specific operation is as follows: open the CL800/CL500/CI800 instrument, select "Comparison Mode" in the display mode, select "Transmittance" in the color parameters, and return to the main measureing interface. Place the illuminance meter measure head near the window, press the measure button, and first measure the irradiance on the air; Then place the glasses on the measureing head of the illuminance meter, maintain the previous measureing position, press the measure button again, and measure the irradiance on the air after placing the glasses. At this time, the transmittance, ultraviolet transmittance, and IR infrared transmittance of the glasses under D65 standard lighting conditions are automatically calculated, which is very convenient. Come and try it out!