1. Luminous intensity-the luminous flux emitted by the luminous body in the unit solid angle, that is, the density of the luminous flux emitted by the luminous body in the selected direction of space. Unit one candela mcd. The luminous intensity of the light-emitting diode usually refers to the luminous intensity in the direction of the normal line (the axis of the cylindrical light-emitting tube). If the radiation intensity in this direction is (1/683)W/sr, it emits 1 candela (symbol is mcd). Since the general LED luminous intensity is small, its luminous intensity is commonly used in candela (mcd) as a unit.

2, luminous flux-the sum of the amount of light emitted per second. Unit-Lumens (Lm).

3, luminous efficiency-the luminous flux emitted by the light source divided by the power consumed by the light source. It is an important index to measure the energy saving of light source. Units-Lumens per Watt (lm/w).

4, color rendering-the degree to which the light source presents the color of the object itself is called significant * *. That is, the degree of color realism. The International Commission on Illumination CIE set the sun's color rendering index at 100. The color rendering index of various types of light sources is different.

5. Color temperature-expressed by absolute temperature K (K = ℃ +273.15), that is, a blackbody is heated. When the temperature rises to a certain level, the color gradually changes from crimson-light red-orange-yellow-yellow-white-white-blue-white-blue. When the color of a light source is the same as that of a black body, we call the absolute temperature of the black body at that time the color temperature of the light source. For example, when the blackbody is heated to show deep red, the temperature is about 550 ℃, that is, the color temperature is 823K.

6. Illuminance-the luminous flux irradiated by the luminous body on the unit area of the illuminated object. Unit-Lux.

7. Luminance-The luminance of a light source or an illuminated surface refers to the light intensity density of its unit surface in a certain direction. It can also be said that the human eye perceives the brightness of the light source or the illuminated surface. Unit: candela per square meter (cd/m2).

8. Brightness-the luminous flux per unit area per unit solid angle in a specific direction. Unit-nit (nit).

Average life-the time when the lamp is in normal use and 50% damaged.

10, glare-in the field of vision with high brightness objects or strong brightness contrast, caused by visual discomfort is called glare, glare is an important factor affecting the quality of lighting.

11. Synchronization-two or more LED lights can run normally according to the program set within an unspecified time. Generally, it refers to the LED lights with internal control mode. Synchronization is the basic requirement for LED lights to achieve coordinated changes.

12. Protection Level-IP Protection Level is to classify lamps according to their dust-proof and moisture-proof characteristics. It consists of two numbers. The first number represents the dust-proof and moisture-proof level of lamps (divided into 0-6 levels), and the second number represents the sealing degree of lamps against moisture and moisture-proof intrusion (divided into 0-8 levels). The larger the number, the higher the protection level.

13, peak wavelength-the light emitted by the light-emitting diode is not a single wavelength, the light emitted by a certain wavelength λ. The light intensity of the maximum, the wavelength is the peak wavelength. Also known as the main wavelength.

14. Half-value angle 1/2 and viewing angle -1/2 refer to the angle between the direction where the luminous intensity value is half of the axial intensity value and the luminous axis (normal). Two times the half-value angle is the viewing angle (or half-power angle).

15. Maximum forward DC current IFm-the maximum forward DC current allowed at both ends of the LED. Exceeding this value can damage the diode.

16. Forward working current IF-the forward current value when the light-emitting diode normally emits light. In actual use, IF should be selected below 0.6 × maximum forward direct current IFm according to needs.