16 with the number of terms related to LED lighting

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1. luminous flux

According to the standard photometric observer radiation effects derived light measure.

Graphic 16 with the number of terms related to LED lighting


In lumens (lm), 1lm = 1cd / 1sr. For clear vision are:

Graphic 16 with the number of terms related to LED lighting

Where:

dΦe (λ) / dλ-- spectral distribution of radiation flux;

ν (λ) - the spectrum of light (as) efficiency;

Km-- maximum radiation spectrum (depending on) performance, in lumens per watt (lm / W). When monochromatic radiation, Km under photopic conditions is 683lm / W (λm = 555nm time).




2. luminous intensity


Luminous body in a given direction of the luminous intensity is the luminous body transmission within the solid angle element dΩ this direction dΦ flux divided by the solid angle element resulting quotient, per unit solid angle of flux.

The unit is candela (cd), lcd = 1lm / sr.

Graphic 16 with the number of terms related to LED lighting

Graphic 16 with the number of terms related to LED lighting

3. luminance

Brightness refers to (reflector) surface emitting (reflective) physical strength phosphor. The human eye from the light source in one direction, in this direction than the light intensity of the human eye "see" in the area of ​​the light source, the light source unit is defined as the brightness, namely luminous intensity per unit area projected on.

Graphic 16 with the number of terms related to LED lighting

Amount by the formula L = d2Φ / (dA · cosθ · dΩ) defined in units of candela per square meter (cd / m2).

Where:

dΦ-- given point by the beam transmission element and contains the given direction within a solid angle dΩ luminous flux propagation (lm);
dA-- include a given point of the beam cross-sectional area (square meters);
θ-- sectional beam angle between the normal to the beam direction.

4. illuminance

It indicates that the brightness of face to face physical quantity. Light is defined as the point on the surface of the incident at this point where the bins on the ratio of the flux bin area. In value, which is equal to the projected luminous flux per unit area.

Bin containing the incident point on the flux dΦ divided by the surface area dA yuan resulting quotient, the unit is lux (lx), 1 lx = 1 lx / m.

Graphic 16 with the number of terms related to LED lighting

5. average illuminance


The average illuminance on the specified points on the surface.
The average illuminance (Eav) = Total light flux (N * Ф) * utilization coefficient (CU) * Maintenance Factor (MF) / Area (m) (suitable for indoor or stadium lighting calculation)


6. maintained average illuminance

Average illuminance on the specified surface of not less than this value. It is illuminating device must be maintained in the moment, the average illuminance on the specified surface.

7. maintenance factor

In the use of a certain period, the average illuminance on the specified surface or average luminance or average illuminance and the ratio of average luminance of the device under the same conditions when the newly installed on the same surface of the resulting illumination device.
Graphic 16 with the number of terms related to LED lighting


8. distribution of luminous intensity


Denotes a light source or luminaire with a luminous intensity curves or tables in the value space in all directions, also known as light.
Graphic 16 with the number of terms related to LED lighting

9. luminous efficacy of a light source


Light flux emitted divided by the quotient obtained from the power source, referred to the luminous efficiency of the light source. In lumens per watt (lm / W).
Graphic 16 with the number of terms related to LED lighting


10. luminaire efficiency


Under the conditions of use prescribed ratio of the total flux within the total luminous flux emitted by the lamp and the lamp all light emitted, also known lamps light output ratio.
Graphic 16 with the number of terms related to LED lighting


11. luminaire efficacy


Under the conditions of use prescribed, total luminous flux emitted by the lamp and its ratio of the power input. In lumens per watt (lm / W).
Graphic 16 with the number of terms related to LED lighting



12. luminous flux maintenance

In the light source to the light flux given time after their initial flux ratio.




13. reflectance


Incident radiation in the spectral composition, polarization state and the geometric distribution at a given state, the ratio of reflected radiation flux or luminous flux to the incident radiant flux or luminous flux.


14. lighting power density (LPD)


Usually installed power per unit area lighting (including light, electricity ballasts or transformers and other ancillary devices), in units of watts per square meter (W / m).

15. room

It represents the geometry of the room or place value, a value of twice the area of ​​the room or place a room or place horizontal and perimeter lighting installers height difference between the height of the work surface.

16. annual lighting exposure
Objects accepted measure cumulative illuminance values, with object illumination and receiving cumulative hours of product expressed in units of hours per year lux (lx · h / a).