Measuring device for ascertaining a measurand of a measurement gas
AssigneeAVL List GmbH
InventorsHerbert Reingruber, Wolfgang Schindler, Klaus-Christoph Harms, Tristan Reinisch
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Abstract
Aspects of the present disclosure are directed to a measuring device for determining a measured variable of a measuring gas by means of a photoacoustic method. In some embodiments, the measuring device includes a flow channel for the measuring gas having at least one feed line, a photoacoustic measuring cell and a discharge line. in such an embodiment, the measuring device further includes at least one acoustic filter member tuned to a useful frequency of the measuring cell, and at least one cavity resonator arranged on the flow channel.
Claims14
A measuring device for determining a measured variable of a measuring gas by means of a photoacoustic method, wherein the measuring device comprises:
- a flow channel configured and arranged for measuring gas, and having at least one feed line;
- a photoacoustic measuring cell;
- a discharge line;
- at least one acoustic filter member configured and arranged to
- be tuned to a useful frequency of the photoacoustic measuring cell, and
- generate negative sound pressure amplification in a first frequency range including a fundamental frequency of the useful frequency;
- and
- wherein the at least one acoustic filter member includes at least one cavity resonator arranged on the flow channel at the at least one feed line and/or at the discharge line.
A method for the suppression of sound interferences in a measuring device for determining a measured variable of a measuring gas by means of a photoacoustic method, the method including the steps of:
- conducting the measuring gas via a flow channel which runs through at least one feed line, a photoacoustic measuring cell and a discharge line,
- providing at least one acoustic filter member in the flow channel;
- adjusting the at least one acoustic filter member to a negative sound pressure amplification in a first frequency range including a fundamental frequency of a useful frequency;
- and
- arranging the at least one acoustic filter member at the at least one feed line and/or at the discharge line.
Dependencies are inferred from the claim text.