Abstract:
An infrared source for use in an infrared spectrometer includes an insulator core (19) having a containment cavity, an outlet port in communication with the containment cavity, and an electrically heated infrared element (41) mounted in the containment cavity (38) with a portion thereof facing the outlet port and with the walls of the containment cavity (38) closely spaced to the infrared element. The insulator core is formed of a ceramic fiber material which has excellent resistance to heat and very low thermal conductivity so that very little heat from the infrared element escapes from the insulator core except as infrared radiation through the outlet port. The insulator core is preferably mounted within a central cavity of a metal housing, and may be sealed off from the ambient atmosphere by an infrared transmissive window (24) sealed to an outlet opening in the housing. The electrical supply lines (15) from the infrared element may extend through an opening in the housing which is closed and sealed to inhibit the passage of gases from the ambient atmosphere into the interior of the housing. Where the infrared element is sealed off from the ambient atmosphere in this manner, potentially corrosive gases will be inhibited from reaching the hot infrared element. This containment of the infrared element within the insulator core allows the element to be maintained at a desired temperature for radiating infrared for use in analytical instruments such as infrared spectrometers, while consuming very low amounts of electrical power.
Abstract:
Source d'infrarouges (200) constituant une source miniature, extrêmement stable et efficace d'énergie infrarouge s'utilisant avec des détecteurs à infrarouges et instrument similaire. La source d'infrarouges décrite par l'invention comporte un détecteur de température à résistance en platine (RTD) (302) intégré à l'élément de réchauffement (306), de façon à constituer un moyen de servocommande électronique de la température de l'élément de réchauffement. Ledit élément (306) et le détecteur RTD (302) sont étroitement couplés thermiquement, de façon à permettre un repérage et une commande précis et continus de la température de l'élément de réchauffement. La conception de la source infrarouge permet d'obtenir un rendement excellent en énergie infrarouge avec une puissance d'entrée dans l'élément de réchauffement inférieure à un watt.
Abstract:
A novel structure for a small, inexpensive, and easily replaced infrared source having near blackbody emission over a spectrum of 2-20 micron wavelengths is disclosed. The source element is self-starting and has a life expectancy in excess of 1000 hours at 1700 degrees K, which requires only 22 watts of power to maintain. Because the source is energy efficient, there is no need of auxilliary cooling or added thermal isolation from adjacent components when the source is used in an instrument such as a spectrophotometer.