Ads
related to: replacement lens for fluorescent 2x4
Search results
Results From The WOW.Com Content Network
Fluorescent lamps in various embodiments. Since their introduction as a commercial product in 1939, many different types of fluorescent lamp have been introduced. Systematic nomenclature identifies mass-market lamps as to overall shape, power rating, length, color, and other electrical and illuminating characteristics.
A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, to produce ultraviolet and make a phosphor coating in the lamp glow.
George Inman later teamed with General Electric to create a practical fluorescent lamp, sold in 1938 and patented in 1941. [6] 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 amount of mercury in a fluorescent lamp varies from 3 to 46 mg, depending on lamp size and age. [4] Newer lamps contain less mercury and the 3–4 mg versions are sold as low-mercury types. A typical 2006-era 4 ft (122 cm) T-12 fluorescent lamp (i.e. F34T12) contains about 5 milligrams of mercury. [5]
The other method is known as the objective lens method which has increased the use of TIRFM in cellular microscopy and increased furthermore since a commercial solution became available. [2] In this mechanism, one can easily switch between standard widefield fluorescence and TIRF by changing the off-axis position of the beam focus at the ...
These new lenses included 35–80 mm f /4–5.6 (with built-in lens cap), 80–200 mm f /4.5–5.6, 35–105 mm f /3.5–4.5, 70–210 mm f /3.5–4.5, and 100–300 mm f /4.5–5.6. [ 4 ] Some of the original lenses were updated and re-released with the same cosmetics and are known as "New" or "Restyled" versions; minor optical updates such as ...