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Fluorescent bulbs contain mercury, a toxic substance. The United States Environmental Protection Agency (EPA) provides safety guidelines for how to clean up a broken fluorescent bulb. [17] Mercury can be harmful to children and developing fetuses, so children and pregnant women should avoid being in the area whilst a broken bulb is cleaned up. [18]
Fluorescent lamps with magnetic ballasts flicker at a normally unnoticeable frequency of 100 or 120 Hz and this flickering can cause problems for some individuals with light sensitivity; [69] they are listed as problematic for some individuals with autism, epilepsy, [70] lupus, [71] chronic fatigue syndrome, Lyme disease, [72] and vertigo.
Intentional light variations are applied for warning, signalling (e.g. traffic-light signalling, flashing aviation light signals), entertainment (like stage lighting) with the purpose that flicker is perceived by people. Generally, the light output of lighting equipment may also have residual unintentional light level modulations due to the ...
Flicker noise is a type of electronic noise with a 1/f power spectral density. It is therefore often referred to as 1/ f noise or pink noise , though these terms have wider definitions. It occurs in almost all electronic devices and can show up with a variety of other effects, such as impurities in a conductive channel, generation and ...
The requirements of a flicker measurement equipment are defined in the international electro-technical standard IEC 61000-4-15. [2]A flickermeter is composed of several function blocks which simulate a 230 V/60 W or a 120 V/60 W incandescent lamp (reference lamp) and the human perception system (eye-brain model).
Flicker vertigo, sometimes called the Bucha effect, is "an imbalance in brain-cell activity caused by exposure to low-frequency flickering (or flashing) of a relatively bright light." [ 1 ] It is a disorientation -, vertigo -, and nausea -inducing effect of a strobe light flashing at 1 Hz to 20 Hz, approximately the frequency of human brainwaves .
The flicker fusion threshold, also known as critical flicker frequency or flicker fusion rate, is the frequency at which a flickering light appears steady to the average human observer. It is a concept studied in vision science , more specifically in the psychophysics of visual perception .
Circular and U-shaped lamps were devised to reduce the length of fluorescent light fixtures. The first fluorescent light bulb and fixture were displayed to the general public at the 1939 New York World's Fair. The spiral CFL was invented in 1976 by Edward E. Hammer, an engineer with General Electric, [7] in response to the 1973 oil crisis. [8]