The world's oldest an incandescent bulb how many years old this year?

It is 115 years old this year. Still fire station in livermore, work in the United States. In order to observe the only one hundred light bulbs, people had to put around it to real-time monitor, allegedly, the bulb to "kill" the two video monitor.

This only one hundred light bulbs work since 1901, has been working continuously for 115 years. In addition to the power failure, the light bulb only in 1976 and 2013 all out again. 1976, firefighters to bulb when we move, in order not to damage the light bulb, they use the screwdriver bulb turned down, but to cut off the rope, escorted by the police and fire engines, displacement to continue to work elsewhere.

People care the centenarians bulbs. It is understood that livermore incandescent light bulb is a manual blowing, built-in carbon filament. Researchers will one hundred bulbs imitations were compared with ordinary light bulbs, livermore of bulb of ordinary difference is mainly manifested in two aspects:

A, it used the filament 8 times thicker than the ordinary filament by;

Used in the 2, one hundred light bulbs filament is likely to be made of carbon filament semiconductors.

The conductor temperature is higher, the holder of common bulb conductive ability will fall; But in one hundred bulbs of conductor temperature is higher, its conductive ability increases.

However, scientists have yet to figure out the exact cause of livermore bulb longevity. Although the exact date of start to work, not clear bulb but firefighters will every year on June 18, as its "birthday".

"Livemore", translated into Chinese is "live longer", so the light bulb in California "live longer region live longer fire station" has been lit up more than 100, if the calculation in 115, the lamp really lit up more than 1 million hours.

Have to say this is a case of magic, due to various reasons, we usually use experience is usually: just bought back light, when using, it is very bright. Use after a long time, the brightness of the light slowly become low, until finally go out.

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We all know that this is the life of the lamps and lanterns in shorten slowly, wait for one day not bright, also died. Many unavoidable confusion, why can have such a process of lamps and lanterns, what reason be cause? In fact, in the end it was the light of lamps and lanterns failure problem, a little short, lamps and lanterns and the human body, as the growth of the service life, the function mechanism of lamps and lanterns is in decline. Both of incandescent lamp, fluorescent lamp, LED lamp light failure was an unavoidable problem.

The droop of lamps and lanterns, is refers to the lamps and lanterns is in after a period of light, the light intensity is lower than the original light intensity, and the lower part is the light of lamps and lanterns of failure. Different types of lamps and lanterns, the cause of light failure is different.

Ordinary incandescent light failure

For ordinary incandescent lamp bubble shell, the greater the droop is smaller, which is proportional to the evaporation deposition of tungsten block light output. And inflatable bulb due to the evaporation part gas stop tungsten filament, so the light failure is small.

If is incandescent lamp with a filament, same in different size of the blister, relatively the same point in time the droop really big blister is smaller than the blister shell. In addition, the same is inflatable bubble, big glass shell bulb internal space, air convection to the glass shell has a relatively large cooling area, relatively small glass shell lamp at a lower temperature, the temperature of the filament is relatively low, luminous efficiency is low, tungsten filament evaporation rate is low, so the light failure is small.

Fluorescent lights failure

Incandescent bulbs will be caused because of the size of the bulb and tungsten filament evaporation droop, fluorescent light failure reason is relatively complex, is usually caused by several reasons:

Phosphor degradation, in the working process of the fluorescent lamp, ultraviolet rays will make color phosphor powder to produce heart, lead to a new absorption band in the lamp, so that the brightness of the phosphor decay.

Film formation of suction light, fluorescent light after a long discharge after work, on the surface of phosphor powder can form a layer of black film suction light, the existence of this layer suction light thin film will cause the decrease of light output.

Working lamp black, fluorescent lamp, glass tube surface will have a large amount of mercury ion or mercury atoms exist, mercury ions ion exchange with other ions inside the glass tube, long down, glass tube will be black, resulting in fluorescent light failure, affect the luminous efficiency.

Typical droop curve graph: T5 fluorescent lamp

The LED light failure

LED lamps and lanterns than incandescent lamp and fluorescent lamp has been improved, but also can not completely overcome the light failure problem. For the LED light failure mainly has the following two factors:

LED product itself quality problem

Mixer adopts LED chip quality is bad, brightness decay rapidly.

Mixer defects in production technology, the LED chip heat dissipation can't good derived from PIN feet, cause the LED chip temperature chip attenuation.

Conditions of use problem

LED to constant current driver, some leds are driven voltage, the LED attenuation too quickly.

Mixer drive current is greater than the rated driving conditions.

Actually some of the reasons for LED products light failure, but the key or the cooling problem. The better the performance of heat dissipation, LED working temperature is lower, the smaller the droop, leds last longer.

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A typical droop curve graph: LED lights

Light failure is a necessary process of lamps and lanterns of work, when choosing lamps and lanterns, we should try to choose the quality and good heat dissipation performance of lamps and lanterns, in use process should also try to reduce the workload of lamps and lanterns, can delay the speed droop, extend the life of the lamps and lanterns.

Whether to cope with droop, varies from place to place

First look at the demand of the intensity of illumination, if an office area, working face illumination really may need 300 lx, if not up to standard will bring fatigue and discomfort.

But for a hotel, 300 lx and 200 lx really is there a difference? Actually makes no difference, when the intensity of illumination is not important, more important is whether the illuminance distribution conforms to the atmosphere and scene construction target, and glare control, the hotel is this, we pay more attention to in the application of the feeling of the people went in, 300 lx and 200 lx actually not big difference, because the visual perception of people is flexible.

Site of illumination, such as a salon's highest over 1000 lx, most dark place 10 lx, we don't feel very comfortable, and light and shade contrast also have an atmosphere, the hotel requires the effect, so for the hotel, intensity of illumination is not that important, that is to say, a range of light failure is not so important.

Graph: the Bali W inside the hotel. High contrast the use of the technique, is from drama stage lighting references, let a space have hierarchy and story, so, can say in these areas, uneven illumination, it is a must.

Graph: sports venues, uniform, standard illumination requirements, became very stringent, light failure is must fully consider the factor of and effectively cope with.

Offices, museums, stadium these places, however, requires that must meet strict illuminance standard, and LED light life is long, we need to consider in the two years later, still have to meet the standards, so we design in the first place, will leave allowance.