Gas Sensing Device with a Gas Filter

Abstract

A gas sensing device includes chemoresistive gas sensing elements, wherein a material composition of a first chemoresistive gas sensing element is similar to a material composition of a second chemoresistive gas sensing element, wherein the first chemoresistive gas sensing element is exposed to an ambient mixture of gases so that first sensing signals depend on a concentration of a first gas and on a concentration of a second gas, wherein the gas sensing device includes a gas filter so that the second sensing signals depend on the concentration of the first gas to a lesser degree than the first sensor signals and so that the second sensing signals depend on the concentration of the second gas, and wherein the gas sensing device estimates the concentration of the first gas and/or the concentration of the second gas based on the first sensing signals and the second sensing signals.

1 .- 11 . (canceled) 
     
     
         12 . A gas sensing device for sensing a first gas and at least one second gas in an ambient mixture of gases;
 a gas filter that is less permeable for the first gas than for the at least one second gas;   a plurality of chemoresistive gas sensing elements including:
 a first chemoresistive gas sensing element of the plurality of chemoresistive gas sensing elements configured for providing first sensing signals, wherein the first chemoresistive gas sensing element is exposed to the ambient mixture of gases so that the first sensing signals depend on a concentration of the first gas in the ambient mixture of gases and on a concentration of the second gas in the ambient mixture of gases; and 
 a second chemoresistive gas sensing element of the plurality of chemoresistive gas sensing elements configured for providing second sensing signals, the gas filter arranged so the second sensing signals depend on the concentration of the first gas in the ambient mixture of gases to a lesser degree than the first sensing signals, and the second sensing signals depend on the concentration of the second gas in the ambient mixture of gases, and the gas sensing device configured for estimating at least one of the concentration of the first gas in the ambient mixture of gases or the concentration of the second gas in the ambient mixture of gases based on the first sensing signals and based on the second sensing signals; 
   an enclosed containment including a wall structure, the second chemoresistive gas sensing element being arranged in the enclosed containment and the gas filter being implemented as a portion of the wall structure of the enclosed containment, the wall structure of the enclosed containment being between the first chemoresistive gas sensing element and the second chemoresistive gas sensing element; and   an enclosed housing including a wall structure, the first chemoresistive gas sensing element and the second chemoresistive gas sensing element being arranged in the enclosed housing, wherein a wall structure of the enclosed housing includes a particle filter impermeable for particles and permeable for the first gas and for the at least one second gas.   
     
     
         13 . The gas sensing device of  claim 12 , wherein a material composition of the first chemoresistive gas sensing element is similar to a material composition of the second chemoresistive gas sensing element, wherein the material composition is suitable for sensing the first gas and the at least one second gas. 
     
     
         14 . The gas sensing device of  claim 12 , wherein the gas filter is less permeable for the first gas than for the at least one second gas. 
     
     
         15 . The gas sensing device of  claim 12 , wherein the first chemoresistive gas sensing element is exposed to the ambient mixture of gases so that the first sensing signals depend on a concentration of the first gas in the ambient mixture of gases and on a concentration of the second gas in the ambient mixture of gases. 
     
     
         16 . The gas sensing device of  claim 12 , wherein the gas filter is arranged to expose the second chemoresistive gas sensing element to a filtered mixture of gases obtained by filtering the ambient mixture of gases with the gas filter so the second sensing signals depend on the concentration of the first gas in the ambient mixture of gases to a lesser degree than the first sensing signals, and the second sensing signals depend on the concentration of the second gas in the ambient mixture of gases. 
     
     
         17 . The gas sensing device of  claim 12 , wherein the first gas is ozone. 
     
     
         18 . The gas sensing device of  claim 12 , wherein the at least one second gas comprises nitrogen dioxide. 
     
     
         19 . The gas sensing device of  claim 12 , wherein a material composition of the first chemoresistive gas sensing element and of the second chemoresistive gas sensing element comprises a mixed oxide or materials comprising carbon. 
     
     
         20 . The gas sensing device of  claim 12 , wherein the gas filter is implemented as a coating of a gas-sensitive area of the second chemoresistive gas sensing element. 
     
     
         21 . A gas sensing system, comprising;
 a gas filter that is less permeable for a first gas than for at least one second gas;   a plurality of chemoresistive gas sensing elements including:
 a first chemoresistive gas sensing element of the plurality of chemoresistive gas sensing elements configured for providing first sensing signals, wherein the first chemoresistive gas sensing element is exposed to the ambient mixture of gases so that the first sensing signals depend on a concentration of the first gas in the ambient mixture of gases and on a concentration of the second gas in the ambient mixture of gases; and 
 a second chemoresistive gas sensing element of the plurality of chemoresistive gas sensing elements configured for providing second sensing signals, the gas filter arranged so the second sensing signals depend on the concentration of the first gas in the ambient mixture of gases to a lesser degree than the first sensing signals, and the second sensing signals depend on the concentration of the second gas in the ambient mixture of gases, and the gas sensing device configured for estimating at least one of the concentration of the first gas in the ambient mixture of gases or the concentration of the second gas in the ambient mixture of gases based on the first sensing signals and based on the second sensing signals; 
   an enclosed containment including a wall structure, the second chemoresistive gas sensing element being arranged in the enclosed containment and the gas filter being implemented as a portion of the wall structure of the enclosed containment, the wall structure of the enclosed containment being between the first chemoresistive gas sensing element and the second chemoresistive gas sensing element;   an enclosed housing including a wall structure, the first chemoresistive gas sensing element and the second chemoresistive gas sensing element being arranged in the enclosed housing, wherein a wall structure of the enclosed housing includes a particle filter impermeable for particles and permeable for the first gas and for the at least one second gas; and   a processing device including a gas concentration estimator having a trained model based algorithm processor with an input layer and an output layer, wherein first sensing data derived from the first sensing signals and second sensing data derived from the second sensing signals are fed simultaneously to the input layer, and wherein the concentration of at least one of the first gas in the ambient mixture of gases or the concentration of the second gas in the ambient mixture of gases are estimated based on output data of the output layer.   
     
     
         22 . The gas sensing system of  claim 21 , wherein the first chemoresistive gas sensing element, the second chemoresistive gas sensing element and the processing device are arranged at a common substrate. 
     
     
         23 . The gas sensing system of  claim 21  further comprising:
 a first heating device configured for heating the first chemoresistive gas sensing element; 
 a second heating device configured for heating the second chemoresistive gas sensing element; and 
 a heat control device in the processing device, the heat control device configured for controlling the first heating device according to a first temperature profile and for controlling the second heating device according to a second temperature device, wherein a maximum temperature of the first temperature profile is lower than a maximum temperature of a second temperature profile. 
 
     
     
         24 . The gas sensing system of  claim 22 , wherein the first chemoresistive gas sensing element and the second chemoresistive gas sensing element are arranged at a common side of the common substrate, wherein the processing device is arranged at an opposite side of the common substrate, wherein the first chemoresistive gas sensing element and the second chemoresistive gas sensing element are electrically connected to the processing device by vias. 
     
     
         25 . The gas sensing system of  claim 21 , wherein the first gas is ozone, the at least one second gas comprises nitrogen dioxide, and wherein a material composition of the first chemoresistive gas sensing element and of the second chemoresistive gas sensing element comprises a mixed oxide or materials comprising carbon 
     
     
         26 . The gas sensing system of  claim 21 , wherein the first chemoresistive gas sensing element is exposed to the ambient mixture of gases so the first sensing signals depend on a concentration of the first gas in the ambient mixture of gases and on a concentration of the second gas in the ambient mixture of gases. 
     
     
         27 . A method, comprising:
 exposing a first chemoresistive gas sensing element to an ambient mixture of a first gas and at least one second gas to cause the first chemoresistive gas sensing element to provide first sensing signals that depend on a concentration of the first gas in the ambient mixture of gases and on a concentration of the second gas in the ambient mixture of gases;   filtering the ambient mixture of the first gas and at least one second gas with a gas filter to provide a filtered mixture of gases;   exposing the second chemoresistive gas sensing element to the filtered mixture of gases to cause the second chemoresistive gas sensing element to provide second sensing signals, the second sensing signals depending on the concentration of the first gas in the ambient mixture of gases to a lesser degree than the first sensing signals and the second sensing signals depending on the concentration of the second gas in the ambient mixture of gases;   estimating a concentration of at least one of the first gas in the ambient mixture of gases or the concentration of the second gas in the ambient mixture of gases based on the first sensing signals and based on the second sensing signals;   arranging the gas filter, as a portion of a wall structure of an enclosed containment, between the first chemoresistive gas sensing element and the second chemoresistive gas sensing element; and   arranging the first chemoresistive gas sensing element and the second chemoresistive gas sensing element in an enclosed housing having a wall structure including a particle filter that is impermeable for particles and permeable for the first gas and for the at least one second gas.   
     
     
         28 . The method of  claim 27  further comprising coating a gas-sensitive area of the second chemoresistive gas sensing element to form the gas filter. 
     
     
         29 . The method of  claim 27  further comprising:
 heating the first chemoresistive gas sensing element according to a first temperature profile; and 
 heating the second chemoresistive gas sensing element according to a second temperature profile, a maximum temperature of the first temperature profile being lower than a maximum temperature of a second temperature profile. 
 
     
     
         30 . The method of  claim 27  further comprising:
 deriving first sensing data from the first sensing signals; 
 deriving second sensing date from the second sending signals; 
 providing simultaneously the first sensing data and the second sensing data to an input layer of a trained model based algorithm processor; and estimating the concentration of at least one of the first gas in the ambient mixture of gases or the concentration of the second gas in the ambient mixture of gases based on output data provided from an output layer of the trained model based algorithm processor. 
 
     
     
         31 . The method of  claim 27 , wherein each of the first and second chemoresistive gas sensing elements comprises a microelectromechanical system (MEMS) structure.