Nondispersive infrared gas analyzer
AssigneeHartmann & Braun Aktiengesellschaft
InventorsWalter Fabinski, Margareta Ascherfeld
Life of this patent
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Abstract
A two-beam, infrared gas analyzer includes a front and a rear detection cell in each path filled with gas of the type to be detected; and a pressure-differential chamber with capacitor pick-up is connected to these front and rear cells. The rear cells are constructed to ensure substantially complete absorption of all radiation of the absorption band being characteristic of the component to be detected. In one example, filters are interposed between front and rear cells for broadband, i.e., nonselective attenuation. Alternatively, the rear cells are connected to a reservoir of the same gas to attenuate pressure variations. Either case enhances frequency selectivity by reducing cross sensitivity.
Claims9
Nondispersive gas analyzer, including means for defining two infrared radiation beam branches, means disposed for modulating the beams of the branches;
- a measuring chamber and a reference chamber disposed respectively in the two branches;
- multichamber detection means including a differential pressure chamber with capacitive pickup for generating a measuring signal, and containing gas components of the type to be detected, the improvement in the detection means comprising:
- front and rear detection chamber means disposed to be effective in each of the branches and connected to the differential pressure chamber, the rear detection chamber means being configured to absorb almost completely the radiation having particular frequency or frequencies of the said gas component to be detected;
- and
- means disposed to provide for nonfrequency-selective attenuation of the effect of radiation on the rear detection chamber means.
Dependencies are inferred from the claim text.