Units of illuminance meters and conditions of application
Many customers will say, I want to buy an illuminance meter, naturally ask what the illuminance meter unit! Now a brief introduction to illuminance, illuminance a unit that reflects the intensity of light, its physical meaning is irradiated to a unit area of luminous flux, illuminance unit is the number of lumens per square meter (Lm), also known as Lux (Lux): 1Lux = 1Lm/m2. 1Lux = 1Lm/m2. As can be seen from the above formula, Lm is a unit of luminous flux, which is defined as the pure platinum at the melting temperature (about 1770 ° C), its 1/60 square meter surface area in 1 spherical degree within the stereo angle of the light radiated. /60 square meters of surface area in 1 spherical degree of the stereo angle of the amount of light radiated.
The above explanation of the illuminance unit seems to be very theoretical and generally difficult to recognize. In order to have a more perceptual understanding of the amount of illumination, an example to illustrate, a 100W incandescent lamp, the total luminous flux emitted is about 1200Lm, if the assumption that the luminous flux is uniformly distributed in half of the sphere, then from the light source 1m and 5m at the value of the illuminance can be obtained in accordance with the following steps: radius of 1m of the hemisphere area of 2π × 12 = 6.28 m2, from the light source 1m The luminosity value at 1m from the light source is: 1200Lm/6.28 m2=191Lux. Similarly, the area of the hemisphere with a radius of 5m is: 2π×52=157 m2, and the luminosity value at 5m from the light source is: 1200Lm/157 m2=7.64Lux.
General: summer in the sun about 100000LUX; cloudy outdoor illuminance is 10000LUX; indoor fluorescent light illuminance is 100LUX; we are 60cm from the 60W desktop lamp on the desktop illuminance is 300LUX; television broadcasting room illuminance is 1000LUX; dusk when the room illuminance is 10LUX; nighttime street lamps illuminance is 0.1LUX; candlelight illuminance (at a distance of 20cm away) is 10-15LUX.
In general, we are in the 250-750LUX about the illumination of the environment is more comfortable, too high or too much illumination, the human eye is also harmed, * direct is myopia, there are a majority of myopia is in the illumination is very low under the environment of the long time to read or excessive use of the eyes, this is also worthy of our attention.
Illuminance has a close relationship with people's lives. For example, sufficient light can prevent people from accidents. On the other hand, too little light can cause much more fatigue than the eyes themselves. Unsuitable or poor lighting conditions are therefore one of the main causes of accidents and fatigue. Available statistics show that about 30% of all accidents in occupational labor are directly or indirectly caused by insufficient light. The light of the stadium (hall) to ** very strict, too strong or too dark light will affect the effect of the game.
So, people live indoors on the illumination of hygiene to ** how? Illumination is a very important indicator in hygiene. Light refers to electromagnetic radiation that can cause the human eye light feeling, when the light into the eye can produce the perception called vision. The light that people see is visible light, which has a wavelength range between 380 and 760 nm (nanometers).
