Patent ID: 6825471
Filing Date: 2004-11-30
Classification: G01N

Abstract:
An infrared gas sensor with an energy supply apparatus for operating at least one radiation source with current or voltage pulses, with at least one detector element emitting an electrical measurement signal, with at least one wavelength-selecting element located between the at least one radiation source and the at least one detector element, and with at least one measurement area arranged between the at least one radiation source and the at least one detector element and disposed in the beam path, and with a switching device to control the pulse duration of the current or voltage pulses, wherein the switching device has means for setting the pulse duration in such a way that the current or voltage pulse is turned off in a manner such that the pulse duration is smaller than the required to reach the maximum (&tgr;MAX) of the at least one measurement signal of the at least one detector element and such that the turn-off takes place when a specific measurement signal value is reached within the pulse duration or the turn-off occurs when a specific value of the first derivative of the measurement signal is reached within the pulse duration or the turn-off occurs when the maximum value of the first derivative of the measurement signal is reached within the pulse duration or the turn-off occurs when a specific value of the integral of the measurement signal over a time interval, starting from the tun-on time t=0 is reached within the pulse duration.