List of other terms of illumination (A-G)
Source: Date:2017-03-28



Alternating current generated by a generator.


Long fluted lamp mounted on ceiling with open overflow.

Safety lighting

Part of the emergency lighting provided to ensure the safety of people in a potentially dangerous process.

The installation height of

Distance between reference plane and lamp plane.

The dark vision

The visual condition when the eye is adjusted to a few hundred Candela per square meter. In this case, rod-shaped cells are considered to be the main active components. The spectrum is colorless.



Discomfort glare

Can cause discomfort, but not necessarily undermine the visual effects of the object's glare.

Opaque medium

A medium that cannot transmit radiation within the desired spectral range.

Semitransparent medium

A medium that transmits visible radiation mainly through diffuse transmission. Therefore the object cannot be clearly seen through this medium.

Standby lighting

The part of the emergency lighting that keeps the normal activity unchanged.

Wavelength (L)

The distance between two points at the same time in the direction of propagation of the periodic wave.

Incandescent lamp

A white light source (often called a bubble or GLS lamp) produced by a current heating element

Thin skylight

A skylight made of opaque or translucent material as a shelter.

Luminous flux

The luminous flux received on the reference surface.


Visual attributes that determine the proportion of a single color in general perception.




The frequency of a monochromatic component of radiation passing through a medium.

Exit lighting

Lighting in emergency lighting to ensure that exports can be effectively identified. Use in normal lighting system interrupt.

Initial luminous flux

Fluorescent light output after 100 hours.

The reference plane

A surface that is measured or described in detail.




Conventional lighting

Adequate and uniform illumination for a particular area without special requirements.

Goniometer photometer

Photometer for measuring directional light distribution characteristic of light source or lamp.

Effective width (of a road)

The horizontal distance between the vertical surface of the lamp shaft and the farthest away from the lamp.

Low pressure mercury (vapour) lamp

Coated with fluorescent powder or not coated with fluorescent powder mercury vapor lamp, where the light source is not more than 100Pa. For example TL lamp.

Low pressure sodium (vapour) lamp

When working, the local gas pressure in the lamp does not exceed 5Pa of the sodium vapor lamp, such as the SOX lamp.

Cloth lamp unilateral

Only one way to be placed on the side of the driveway.

Monochromatic radiation

Radiation characteristics are determined by a single frequency. In practice, the radiation in a very small frequency range is called monochromatic radiation.

Directional lighting

The illumination of a light on a work surface or object, mainly from a certain direction.


A subjective assessment of the apparent difference between two parts of a region at the same time or continuous observation. (see brightness contrast) contrast field values see domain values

Symmetrical distribution

For the light source, there is at least one axial symmetry or the intensity distribution.


The part of a luminaire that is designed to prevent the light source from being seen in a given range. Note: in practical applications, the screen is also used as a light controller.

The filament

A wire made of tungsten, such as an incandescent lamp.

The lamp

The utility model relates to a device for distributing, filtering and converting light emitted by a light source, which comprises a plurality of accessories for installing and protecting the light source and various devices which are necessary for connecting the circuit.

The lamp life

When a group of light sources are lit at the same time, the time of a certain proportion of the lamp goes out.

Point source

The size of a light source that is small in size and is negligible in comparison to the distance between the light source and the object being illuminated.

Electronic (high frequency) ballast

Ballast for converting a current into a high frequency discharge lamp by the aid of an electronic component. Its frequency is generally higher than or equal to 20000 Hz.

The capacitance

A device for storing electrical energy, which is commonly used for power factor correction and light source stability control.

The electrical efficiency of

For ballasts, defined as PL/Pin, where PL is the light source power, Pin is the power input ballast. For example, if 10% of the total power is lost by heat conduction, the ballast efficiency is about 90%. Compared with standard inductance ballast, electronic ballast has higher electrical efficiency. Because the electronic ballast can reduce the power loss under the same luminous flux of the light source output and the inductance ballast, the utility model has the advantages of more energy saving.


Electromagnetic ballast (inductive ballast)

The ballast is assembled using an assembled iron core and a coil, which is used for transmitting current to start and burn a fluorescent lamp and a high-intensity gas discharge lamp (HID).

Contour curve (Figure)

For a given observer position, the brightness of each point on the surface or curve is the same as that of the light source or the light source associated with the light source.

Equal intensity map

A combination of a series of equal intensity curves.

Equal intensity curve

In a virtual sphere with a light source as the center of the circle, the light source is connected to the point of the same direction of the light intensity on the sphere.

Such as lux curves (Figure)

The set point has the same lux value a surface.

Equivalent yarn brightness

In order to have the same feeling as the existence of the loss of glare loss under the condition that the difference value of the luminance difference field is not present in the absence of an energy loss glare, the brightness of the light is superimposed on the background and the object.

Equivalent adaptive luminance

When the uniform luminance value of the observer is the same as that of the actual non-uniform luminance distribution, the equivalent luminance is the uniform luminance.

Illuminance curve

A set of points with the same illuminance on a surface.



EMI (electromagnetic interference)

Electrical interference caused by electrical or electronic equipment. The level of interference of high frequency electronic equipment shall be subject to the provisions of the Federal Communications Commission (FCC) or the International Electrotechnical Commission (IEC).




In a plane, a wide range of light intensity angle contained within the polar curve of the radius vector of length greater than a specified fraction of the maximum, which is defined as the beam divergence. Note: specific ratios are generally used for 1/10 (USA) and 1/2 (Europe). The divergence is also known as the "1/10 peak divergence" or "the 1/2 peak divergence".


Device for changing spatial distribution of luminous flux of light source by using reflection phenomenon.

Reflectivity (formerly called reflection factor)

The ratio of the reflected radiant flux or flux to the incident flux.


The energy of an atom, molecule, or ion that is produced by the excitation of an energy in a range of wavelengths or wavelengths, which exceeds the energy of the radiation produced by the material at the same temperature.

Peak factor (lamp current crest factor)

The ratio of peak current to RMS (RMS) or average working current.

The peak intensity of

The maximum intensity of a light source or luminaire in a given direction.

The discharge

In a gas or vapor, the process of producing and migrating charged particles through a gas or vapor region under the influence of an electric field. In a fluorescent lamp, an electrode is a metal filament that is emitted or absorbed. The negative electrode (cathode) produces a negatively charged free electron, which is absorbed by a positive electrode (anode) and generates an electric current and an arc between the poles.

Discharge lamp

A light source that is directly or indirectly discharged by a mixture of gas, metal vapor, or a mixture of gases and vapours.


For the design of the light projection system, generally can be projected in any direction and has a waterproof anti wind structure.


The emission or transfer of energy in the form of electromagnetic waves or particles.

The radiation power

The ability to transmit, transfer, or receive in the form of radiation. Unit: Watt, W

The radiation efficiency (E)

The ratio of the radiant flux (power) and the consumed power emitted by the radiation source.

Radiant energy (Qe, Q)

The emission, transfer, or reception of energy in the form of radiation. Unit: Joule, J

Radiant flux

The radiant energy received by E (Ee) on a specified surface area per unit surface. Unit: W/m2

Antispray lamps

Water jet lamp.

Dustproof lamp

In the environment with more dust, the dust can be prevented from entering into the lamp with certain specific properties or characteristics.

Water drops lamps

When the lamp is installed in the specified working position, the falling water drops in the vertical direction can be prevented from entering the lamp.

Waterproof lamps

When immersed to a specified depth can withstand the penetration of water lamps, but not too long under water. Diving lamp.

Vapor lamp

Lamp capable of preventing a particular steam or gas from entering the lampshade.

Waterproof lamps

Lamp for outdoor to prevent rainwater infiltration.




A radiation, such as visible radiation, that can cause direct visual perception.

Light stimulation

Visible radiation entering the human eye.

The light cycle

Natural or artificial light and dark cycles that affect biological organisms.

Photometric measurement

A method of measuring the amount of radiation based on a given optical function, such as V (lambda) and V '(lambda).

The intensity distribution of

Light intensity distribution of light source or lamp in every direction of space.

Intensity curve (table)

The light intensity is given by polar coordinates or graphs, and the values in the table are the light intensity of the light source at 1000 lumens. For the non symmetrical distribution of light intensity, the intensity distribution of two different planes can be used to represent the intensity distribution of the lamp. Among them, the two planes are

1 through the vertical plane of the longitudinal direction of the luminaire.

2 plane perpendicular to the plane above.

Note: intensity meter can be used:

1 describe the light intensity distribution;

2 to calculate the illumination of each point;

3 used to calculate the brightness distribution.

Light intensity (Iv, I)

The luminous flux emitted by a light source in a given unit. Unit: Kander

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