First, roughly judge the six parameters of the LED's good or bad: 
3.1, luminous flux ( ¢ ) unit is lumens (lm)
Note: The luminous flux is directly determined by the chip brand, and all of our bulbs are provided by Taiwanese chip Guanghong brand.
3.2, color temperature (k) unit is Kelvin
3.3, color rendering (ra) color rendering index
3.4, light source efficiency (lm∕w)
3.5, the power factor of the power supply
3.6, heat dissipation effect
Need to meet the lights of these six parameters, basically can determine the quality of a lamp!
Second, power selection
LED bulb , professionally known as LED bulb , its most common household power is 3W, 5W, 7W, 9W, 12W, 18W, 21W, 24W, even larger power, 40W, 80W, 120W , 150W, etc.
3W bulbs are generally used on table lamps and bedside lamps.
5W bulbs are generally used on floor lamps.
7W bulbs are generally garages, babysitters, etc.
Personal idea: like the big chandelier in the living room, generally use 3W, because it may use 6-30 bulbs on one lamp, the number of light sources determines his brightness. Like the desk lamp\floor lamp, the power of the selection A bigger light bulb, according to Taobao, which I know, many sellers have falsely reported the existence of W number in power.
Third, the lamp head selection
Fourth, the effect of the show
V. Summary: In fact, no matter what LED you buy LED, you don't look at the appearance, but look at the heart inside. It doesn't work. You need the factory to use the spectral analysis system to measure the corresponding test report. There are at least five reports on the report. Parameters we can compare, heat dissipation parameters, it depends on the aluminum shell, light failure can not be seen with the naked eye, all need professional equipment to measure.
Sixth, price analysis:
For example: bulbs can be divided into: chips, aluminum substrates , housings, power supplies, these parts. Each part has a different brand, different batches, and different prices. Equivalent to a free combination. Every part is used well, then the price is very high, otherwise the price is very low; some parts are used well, some are used badly, the price is moderate.
So how should we identify it?
1. Let the seller take out the test report and see five parameters at once.
2, Taobao recommended not to buy products below 8 yuan, after all, LED lights have not yet reached the stage of popularization, the national standards have not yet come out.
3, look at the shell, it determines the life of the LED lamp beads (heat dissipation); the appearance is the same, the thickness of the aluminum determines the price.
Seven, the choice of color temperature
1, the color of the light: yellow: color temperature: 2700-3500K. (to achieve a warm effect, warm colors)
White light: Color temperature: 6000-6500K. (Achieve clean and tidy effect, cool color, now used more in summer)
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There are two working modes: automatic setting time and random time. It can be placed in toilets, kitchens, office buildings, hospitals, banks and other places.Suitable for a variety of viscous liquids, such as hand soap, detergent, disinfectant, sunscreen, etc. It can be placed in toilets, kitchens, office buildings, hospitals, banks and other places.
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