Broadband resonator-amplified optical absorption spectroscopy

Abstract

The invention relates to a method for determining concentrations of absorber gases by means of a spectroscopic measuring device (1), wherein wavelength-dependent measured values are determined for a light intensity, and a wavelength-dependent measured value function is represented therefrom. A wavelength-dependent theoretical function is defined, which includes a calibration parameter as well as the concentrations as parameters. The calibration parameter is defined as a function of a device parameter and a correction factor, which depends on the concentrations. A cycle comprising a sequence ofsteps is consecutively carried out several times, wherein; in a first step, a numerical value for the correction factor is calculated from defined assumed values of the concentrations; in a second step, the theoretical function is determined via the calculated numerical value; in a third step, concentration values are determined by a compensation calculus between the theoretical function determined in the first step and the measured value function, and established as new assumed values. The assumed values determined in the third step of the last cycle are output as measured values.

Description

technical field [0001] The invention relates to a method for determining the concentration of an absorbing gas in a gas mixture to be measured using a spectroscopic measuring device according to the preamble of claim 1 . The invention also relates to a spectroscopic measuring device. Background technique [0002] Traditionally, spectroscopic measuring devices are used to determine the concentration of absorbing gases in the gas mixture being measured. For example, the gas mixture to be measured may be ambient air in which the concentration of absorbed gas is to be determined. Absorbing gas is a general term for gas compositions that absorb light in a specific wavelength range. For example, such as NO, NO 2 , NO 3 or O 3 The trace gases are covered by the term "absorbing gas". In particular, the concentration of such trace gases is often measured using corresponding spectroscopic measuring devices. The basic principle of all spectroscopic measurement devices is that ea...

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Problems solved by technology

This is complex and difficult to implement error-free, making the method involve prohibitive costs and high error rates

Furthermore, in this approach, even when used for I 0 In the case where the states of the measuring device during the two measurements of (λ) and I(λ) are assumed to be perfectly matched, the calculation of K(λ) is always limited by the accuracy defined by the characteristics of the measuring device, especially the spectral resolution

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