![]() The filament acts as an electrical resistor, which dissipates power proportional to the voltage applied, times the current through the filament. ![]() ![]() The tungsten filament of a vacuum incandescent lamp is heated to temperatures where visible light is emitted by resistance heating. In-Depth Technical Information - Vacuum, Gas-Filled and Tungsten Halogen Lamps Spectral Radiation Output for Tungsten Filament Lamps ILT Does NOT block UV radiation from our tungsten halogen lamps for this reason. Some radiation output can be obtained at 320 and 340 nanometers. Tungsten Halogen Lamps are ideal light sources for spectrophotometers as they provide broad band spectral radiation ranging from the ultraviolet, through the visible and into the infrared out to five microns. Lamp seal temperatures must not exceed 350C or oxidation of the molybdenum ribbon will occur resulting in premature lamp failure. Operating Tungsten Halogen Lamps at voltages exceeding design voltage is not recommended as the lamps are normally designed to their maximum limits. However, on rare occasions tungsten halogen lamps de-rated by more than 10% could experience an adverse reaction of the corrosive halogen attacking the tungsten filament causing premature lamp failure. Burning the lamp at design voltage for a short period of time can usually clean up lamp blackening due to temporary operation in such a voltage range. If wall blackening is noticed, the operating voltage range at which this occurs should be avoided. By the time the wall temperature drops to a point where the halogen cycle ceases to function, the filament temperature has diminished to a point where the tungsten evaporation is negligible. Tests reveal that in most cases this reduced operating condition is not detrimental to the operation of the lamp. A reduction of voltage exceeding 10% from the design voltage will probably result in the wall temperature falling below the required 250C. These lamps have been designed to maintain this required wall temperature when operated at design voltage. One is to generate light, and the second is to generate the heat necessary to obtain a wall temperature exceeding 250C. The filament of a Tungsten Halogen Lamp has two purposes. The tungsten deposits onto the colder portions of the filament, and the halogen is freed to continue the cycle. The halide compound reacts at the filament where temperatures approximating 2,500C cause the tungsten and halogen to dissociate. ![]() As the quartz envelope wall reaches a temperature of approximately 250C, the halogen reacts with the tungsten to form tungsten halide, which is freed from the wall of the lamp and migrates back to the filament. The halogen gas reacts with the tungsten that has evaporated, migrated outward, and been deposited on the lamp wall. Tungsten Halogen Lamps are similar in construction to conventional gas filled tungsten filament lamps except for a small trace of halogen (normally bromine) in the fill gas. How Tungsten Filament Halogen Lamps Work (Brief Overview) ILT offers a large selection of gas-filled lamps in a variety of sizes, bases, and gas types including T-1 3/4, G4-G10 bases, Bi-pin, wire lead, MR3 - MR11 reflector assembies, with gasses including Halogen, Xenon, Argon and Krypton To speak with one of our lamp experts, inquire about a customized lamp, or to ask about a sample, contact us using the form here. Many of our lamps can be purchased right from our e-store. Below is technical and application information on ILT's Tungsten Halogen and Gas-Filled Lamps. ![]()
0 Comments
Leave a Reply. |