Photoacoustic gas sensor device
AssigneeSensirion AG
InventorsThomas Uehlinger, Christophe Salzmann
Life of this patent
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Abstract
A photoacoustic gas sensor device for determining a value indicative of a presence or a concentration of a chemical component in a gas comprises a substrate and a measurement cell body arranged on a first side of the substrate. The substrate and the measurement cell body define a measurement cell. A cap is arranged on the first side of the substrate within the measurement cell. The cap and the substrate define a cap volume. The cap and the substrate acoustically seal the cap volume. A measurement volume is confined by the measurement cell body, the substrate and the cap. An aperture is provided in the measurement cell for the gas to enter the measurement volume. Electrical components are arranged on the first side of the substrate and in the measurement cell.
Claims19
A photoacoustic gas sensor device for determining a value indicative of a presence or a concentration of a chemical component in a gas, the photoacoustic gas sensor device comprising:
- a substrate,
- a measurement cell body arranged on a first side of the substrate, the substrate and the measurement cell body defining a measurement cell,
- a cap arranged on the first side of the substrate within the measurement cell, the cap and the substrate defining a cap volume, and the cap and the substrate acoustically sealing the cap volume,
- a measurement volume confined by the measurement cell body, the substrate and the cap,
- an aperture in the measurement cell for the gas to enter the measurement volume,
- electrical components arranged on the first side of the substrate and in the measurement cell, comprising at least:
- an electromagnetic radiation source for emitting electromagnetic radiation into the measurement volume,
- a pressure transducer for measuring a sound wave generated by the chemical component in response to an absorption of the electromagnetic radiation by the chemical component present in the measurement volume,
- a controller configured to control the electromagnetic radiation source,
- wherein the pressure transducer is arranged outside the cap volume and at least one of the electrical components other than the pressure transducer is arranged in the cap volume,
- wherein the controller is arranged in the cap volume, and
- wherein the controller is configured to process an electrical signal supplied by the pressure transducer that is indicative of the presence or the concentration of the chemical component in the gas.
A method for manufacturing a photoacoustic gas sensor device for determining a value indicative of a presence or a concentration of a chemical component in a gas, the method comprising:
- providing a substrate,
- mounting electrical components on a first side of the substrate, preferably in a SMD process, the electrical components comprising at least:
- an electromagnetic radiation source for emitting electromagnetic radiation,
- a pressure transducer for measuring a sound wave generated by the chemical component in response to an absorption of electromagnetic radiation by the chemical component,
- a controller configured to control the electromagnetic radiation source and configured to process an electrical signal supplied by the pressure transducer that is indicative of the presence or the concentration of the chemical component in the gas,
- mounting a cap on the first side of the substrate, the cap and the substrate acoustically sealing a cap volume, and the cap enclosing at least the controller but not the pressure transducer,
- mounting a measurement cell body on the first side of the substrate thereby enclosing the cap and electrical components arranged outside the cap, wherein the measurement cell body and the substrate from a measurement cell, wherein the measurement cell body, the substrate and the cap confine a measurement volume into which the electromagnetic radiation is emitted, and wherein the measurement cell comprises an aperture for the gas to enter the measurement volume.
Dependencies are inferred from the claim text.