Multi-frequency sensing system and method

A sensor device comprising:

• at least one electrochemical (EC) gas sensor;
• at least one metal-oxide semiconductor (MOS) gas sensor;
• and
• control circuitry configured to:
• provide one or more EC excitation signals to the at least one EC gas sensor;
• provide at least two MOS alternating current (AC) excitation signals to the at least one MOS gas sensor;
• and
• detect at least two gases based on:
• receiving a plurality of EC response signals from each EC gas sensor of the at least one EC gas sensor in response to each EC excitation signal of the provided one or more EC excitation signals;
• receiving at least two or more MOS response signals from each MOS gas sensor of the at least one MOS gas sensor based on providing the at least two MOS AC excitation signals;
• determining a multivariate response pattern based on the plurality of EC response signals and the at least two or more MOS response signals;
• and
• differentiating between the at least two gases in contact with the sensor device based on the multivariate response pattern.