The scientific research coiled filament operates at approximately 975°C when powered with 11 watts for the PT IR11K and 1200°C when powered with 20 watts for the PT IR18K. The radiating element of the PT IR11K is a coil of resistance wire which has a high emissivity in the Infrared spectral region. The coil is supported on a grooved cylindrical substrate of alumina, resulting in the windings being electrically insulated from each other. This contributes to a more uniform radiating source. The unit does not require operation in a sealed atmosphere. The header is fabricated from cold-rolled steel. The support pins are hermetically sealed in glass. The PT IR18K is designed for those customers who require higher temperatures and greater output from their infrared source. These emitters are manufactured using a patented silicon nitride material. The advanced ceramic technology ensures a very stable product. Their robust design ensures intrinsic physical and thermal strength. When operated at 12 volts/20 watts the PT IR18K reaches 1200°C. These silicon nitride emitters are mounted in a 1 inch parabolic reflector for extremely efficient collimation of energy. This unit is our highest output IR product.