THE MAGIC OF FLUORESCENCE

fluoresence this that magic property of various materials to Glow mysteriously weirdly when subjected to certain invisible spectral rays such weird and beautiful forms of luminescence in solid materials were first recorded in history one night almost four centuries ago when an Italian Alchemist vincenzio casarola discovered some glowing beite in the Hills near his home in bolognia it is from a similar phenomenon from fluorescence that a fundamentally different principle of lighting a new form of light source has been developed from the beginning of History man depended upon some form of fire or heat for light many millions of years ago when man first carried a flaming into his cave he brought light indoors thus was man's long fight against Darkness begun the caveman literally held Aloft the torch of civilization a few million years later about 4,000 BC the oil lamp was developed its illumination was little if any better than that of the burning then many many more centuries elapsed before the invention of the candle but its illumination was no great improvement over that of the pottery lamp not until the 18th century did man devise a means of protection for the flame of his light the lamp chimney was the first scientific example of an accessory to the source of life it tripled lighting efficiency the first permanent lighting installation was made possible by the piping of gas early in the last century but as marvelous as gas light seemed to be it was still in effect an open flame and could not be adapted for Universal use then in 1879 Thomas Edison devised the first practical incandescent lamp and in this single great invention the basis for more progress was made in lighting than had been made before in all time from Edison's first carbon lamps to the tungsten lamp to the present gas filled lamp science in a very few years developed the incandescent lamp so efficiently adapted to many varieties of usage today the Great era of modern lamp research had begun industry's Laboratories took over Man's age-old Battle to banish darkness in these Laboratories researchers made Discovery after discovery of new efficiencies and new Comforts of Better Living Through better light at less cost tracing back to casola's First frightened glimpse of a glowing Stone modern lamp research solved countless problems they tested and discarded they tried and ear but always they progressed until in 1938 this entirely new kind of artificial light fluorescent light was made available for man's use here electricity that formerly was wasted in heat is turned into more light more pleasing light more abundant light without increased lighting costs and so this companion to the incandescent lamp marks a new great stride forward for now man is no longer merely fighting Darkness he is beginning to move the sun indoors the energy available to man comes largely from the Sun in the form of energy waves the different kinds of energy are spread out in what is called a spectrum the position in the spectrum is an indication of the wavelength of the energy most wavelengths cannot be seen by the human eye they are invisible only the wavelengths shown here in color are visible to man and research has discovered that it is precisely at the invisible ultraviolet wavelength known to science as 2537 where we find the original energy that has made practical the modern fluorescent lamp the fluorescent lamp is an electronic device so let's move in and see how the electron is employed to produce the almost magical 2537 energy the lamp is composed principally of an electrode which acts alternately as a cathode and an anode and at each end of the tube an inert gas argon to Aid in starting a tiny droplet of mercury and a fluorescent material called a phosphor coating the entire inside of the tube when the lamp is turned on the electrical current causes the electrode wire to heat up this occurs in a very short time after which voltage is applied to the ends of the tube as the electrode heats up billions of electrons are violently boiled out these little Fells are actually only about two Tri of an inch in size they're just little bits of things forced out by the Heat and voltage they leave the electrode with terrific speed but they soon tend to slow down behind them come more and more electrons if we don't watch out there's going to be a nasty traffic jam right near the electrode but fortunately these same swiftly moving electrons hitting atoms of argon and Mercury instantly and mysteriously change them so that they act as traffic cops these cops help to unsnarl the jam and assist millions of the electrons toward the electrode at the other end of the tube through this action an alternating current Arc is established in the quick starting lamp this action happens instantaneously the ark causes the Mercury to vaporize and greatly increase the number of mercury atoms throughout the tube this little mercury atom is going about minding his own business when suddenly a free electron going at just the right speed collides with him knocking him for the proverbial Loop the poor little mercury atom immediately tries to recover he tries to stop himself and in order to get rid of his excess energy he converts it mysteriously to radiation the magic 253 7 when these invisible radiations strike the phosphor coating on the inside of the tube they are transformed into visible light most of the materials used in coating the tube are sythetic phosphor not found in nature they were developed through lamp research at n Park by exhaustive experiments with thousands of materials and as he saw often the case these synthetic phosphor are far superior to those found in nature in fact many phosphor used today are not found in nature in that form here synthetic phosphor are transforming the magical 2537 into very colored efficient economical fluorescent light outwardly the fluorescent lamp appears to be simple at first glance it seems to be no more than a bit of glass a bit of metal from all over the world come a great arals to be used in this lamp metals and Alloys rare gases chemicals of various kinds Dolomite arsenic tonium magnesium these and many other materials each with its own special function are com bed in a single lamp but the efficiency and quality of this fluorescent lamp requires Precision design and precision manufacturing while it is true that fluorescent lamps look much alike such factors as the ratio of tube length to diameter the infinitesimal exactitude of phosphor Crystal size the hair fine uniform of electrode wire these and a host of other possible combinations must be just right as determined by thorough lamp research to give the greatest lighting efficiency and to keep these combinations exactly right quality control must be rigidly applied at every step of manufacturer in the factories where these lamps are made even such a little thing as the special ink used to imprint the designation of size and color is rigidly controlled it is mixed from seven different ingredients next the phosphor coating is applied inside the tube air pressure forces the fluid evenly through the tube watch it lady uhoh I thought surely it was going over that time pretty isn't it I mean the liquid in the tubes after the coating has been heat dried it is checked for thickness in a special reflectometer the thickness of the coating must be uniform within 3 100,000 of an inch the mount supporting the electrode is an assembly of exhaust tube glass flare and lead wires there is one mount for each end of the tube mounts two are closely scrutinized for possible minute defects the next step is the sealing machine here the mounts meet the coated tube the mounts are sealed to the ends of the tube by melting and fusing the glass together one end is completely sealed airtight the other is provided with a small exhaust tube through which air can be drawn to create a vacuum inside the lamp the air is exhausted from the lamp by an ingeniously designed exhausting machine the lamps move around the circle and air is drawn out as they pass through an oven the heat facilitate the removal of the air and a high degree of vacuum is achieved low voltage current is supplied to the electrode to provide additional heat and to cause the coating on the electrode to cast off all impurities next the machine automatically measures and injects a tiny exact amount of mercury and a charge of pure super dry AR and gas is put in with just the correct pressure to assure easy starting and long life for the lamp still in the same machine the little tube through which the air has been removed is sealed off and Mr electron and his fellow workers are now hermetically isolated from the outer world in the next operation the lead wires are threaded through the Hollow contact pins in the base the base filled with special cement is sealed to the tube by baking at an exactly controlled temperature the extra lengths of lead wires are cut off and the leads are soldered to the pins now you might think that the painstaking job of making a lamp is completed but no there are still a lot of tests and inspections to be made on these racks the lamps are being seasoned stabilized as it were before final checkups are made here the lamp is operated under extremely adverse conditions conditions rarely encountered in ordinary use and All Phases of its performance are thoroughly checked in all some 480 tests and quality controls are applied before the finished lamp is ready to be packed and sent on its way to uhoh what's this taking the lamp out of the carton again and it hasn't even left the plant oh that's right she's a special inspector and she works for an outside concern one of the compan country's leading Testing Laboratories and she's giving the lamp another good going over on a strictly impartial and unbiased basis she will test at least one lamp from each carton her reports cover 60 different checkups and tests and she sends them directly to her boss in New York every day or so a summary of these reports is given to the manufacturer the various groups compete with each other for the best workmanship alert always for new means of quality control now all of these tests and inspections and checkups and controls of course cost something but every dollar invested by the manufacturer to make lamps stay brighter longer returns to the public many hundred fold by making possible better light at lower cost and this idea of light at lower cost applies to fluorescent lighting even though the original power source is the same electric current we have used for so many years while the price trend of most Commodities during recent years has been generally upward the cost of lighting due to the Improvement in lamps the reduction in lamp prices and the lowered cost of electricity has gone steadily downward among all the established Sciences the technology of lighting is comparatively young yet truly remarkable forward strides have been made in this science in very recent years the quality and versatile usefulness of man-made light have become greater and greater while its cost has become less and less [Music] thus does the science of lighting bring constant Improvement in the comfort Health protection and livability of our homes in the beauty and utility of our public buildings in our stores large and small and in the efficiency and productiveness of our industry as man progresses toward the ultimate accomplishment of moving the sun indoors a great and significant part in this achievement is being played by the magic of fluorescence [Music]