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Lumens is the total amount of light a light source (a light bulb, for instance) throws in all directions. Lux (lumens per square meter) can measure how intense light from that light source is when looking toward it from a certain distance. Lux depends greatly on how far away you are from a light source. At any given instant, light is thrown from the source in a perfect sphere.

If you are trying to calculate how many lumens your light bulb shines and you have a light meter that gives you lux, point your meter at the light, then take your lux multiply by 12.57 (pi times 4). Then, multiply this by the distance of your light meter from the light bulb (in meters) squared. That will give you the lumens of the light bulb. In equation form, where lm is lumens, r is your distance from the light source, and pi is (come on) about 3.14, lux=lm/(pi*4*(r^2)), or lm=lux*pi*4*(r^2). The (pi*4*(r^2)) part is used to calculate the surface area of a sphere around the light source.

Note: this calculation does not account for reflected light, and will only work on an exposed light bulb. Lights housed in a reflective cone (like in a flashlight) are designed to project light in one direction and (within the spot where light is projected) will have a lux much higher at any given distance than if the light bulb wasn't housed in a cone.

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Q: How do you calculate lux value for a light fixture?
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What is measured in units of lux?

Lux is a measurement of light, the brightness at source. The higher the number the brighter the sourceIllumination, the light output of a light bulb.


How do you calculate a lux level in a room?

Light Level or Illuminance, is the total luminous flux incident on a surface, per unit area. The work plane is where the most important tasks in the room or space are performed.Measuring Units Light Level - IlluminanceIllumenance is measured in foot candles (ftcd, fc, fcd) (or lux in the metric SI system). A foot candle is actually one lumen of light density per square foot, one lux is one lumen per square meter. 1 lux = 0.0929 foot candle = 1 lumen /sq meter = 0.0001 phot1 ftcd = 1 lux / 10.7521 lumen/sq ft = 1 foot candle = 1x104 lux = 1 phot


1 watt equal to how many lux?

Lux is unit for measuring the illumination (illuminance) of a surface. It is the amount of light received per unit of surface area. You can' t convert watt, which is power, to Lux.


How many candelas equals 1 lux?

They really aren't equal because they measure two different things. However, they are related to each other.The Candela is the measure of the luminous intensity of a light source. A higher Candela number means a brighter light. Lux is a measurement of light density and means lumens per square meter. Again, a greater number of lux means that the surface being illuminated by the light is is receiving more light per square meter.The formula for calculating the conversion of candelas to lux is E = I/(D*D) where E is the Illuminance of the the surface in lumens per square meter (lux), I is the Intensity of the the light source in Candelas and of course (D*D) is the square of the distance from the light source in meters.Therefore 1 Candela will illuminate a surface with 1 Lux only at one meter from a light source. At different distances it will illuminate to different densities of light.For example: Solving for E, that same one candela light source would only read 1/4 lux at two meters [ 1/(2*2)] and 1/16 lux at four meters [1/(4*4)].If you know the lux at a given distance in meters from the light source you can solve for I and it will give you the intensity of the light in Candelas. From that you can calculate the intensity of the light.For example: Solving for I, multiply the lux times the square of the distance in meters and you will have the intensity of the light source in Candelas.So a reading of 8 lux at a distance of 3 meters would mean that the light source has an intensity of 8*3*3 or 72 candelas.


What do you use to measure light?

there is an instrument called lux meter. i believe that it works with a complex electronics circuitry using light sensitive devices. it directly gives the reading in lux.

Related questions

How do you calculate the lux value for a light fixture for industrial tank area?

relation between lux and candla


What does lux stad for?

Lux is latin for light


What is the Latin word for divine light?

holy light = lucem sanctam


What does this Latin word Lux mean in English?

"Lux" is "light."


How do you find out lumen from lux?

There's not a direct conversion, but both are based on the candela, a unit of luminous intensity. There is a nice explanation of the difference between lumens and lux at http://en.wikipedia.org/wiki/Lumen_(unit).Lumens is the total amount of light a light source (a light bulb, for instance) throws in all directions. Lux (lumens per square meter) can measure how intense light from that light source is when looking toward it from a certain distance. Lux depends greatly on how far away you are from a light source. At any given instant, light is thrown from the source in a perfect sphere.If you are trying to calculate how many lumens your light bulb shines and you have a light meter that gives you lux, point your meter at the light, then take your lux multiply by 12.57 (pi times 4). Then, multiply this by the distance of your light meter from the light bulb (in meters) squared. That will give you the lumens of the light bulb. In equation form, where lm is lumens, r is your distance from the light source, and pi is (come on) about 3.14, lux=lm/(pi*4*(r^2)), or lm=lux*pi*4*(r^2). The (pi*4*(r^2)) part is used to calculate the surface area of a sphere around the light source.Note: this calculation does not account for reflected light, and will only work on an exposed light bulb. Lights housed in a reflective cone (like in a flashlight) are designed to project light in one direction and (within the spot where light is projected) will have a lux much higher at any given distance than if the light bulb wasn't housed in a cone.AnswerA lux is a special name given to a lumen per square metre. To convert lux to lumens, you need to multiply the illuminance (light arriving) on a surface, in lux, by the area of that surface, in square metres.


Meaning in English of latin word lux?

Lux means light


What is measured in units of lux?

Lux is a measurement of light, the brightness at source. The higher the number the brighter the sourceIllumination, the light output of a light bulb.


How do you say the power of light in Latin?

Light of God would translate into Latin as lux dei.


Is light measured in Lamberts?

No. Lux.


What does lux means?

Light of life.


What is the Latin translation for light?

Lux


Latin for light?

Levis; lux.