Photoacoustic sensor, method for checking a gas-tightness, and system

A photoacoustic sensor, comprising:

• a hermetically sealed sensor cell filled with a gas;
• a gas excitation device, inside the sensor cell, to thermally excite the gas;
• a microphone to output a microphone signal that is based on the thermally excited gas;
• and
• a testing unit to use the microphone signal as a basis for testing a gas-tightness of the sensor cell.

A method for testing a gas-tightness of a hermetically sealed sensor cell of a photoacoustic sensor filled with a gas, comprising:

• exciting the gas inside the sensor cell using a gas excitation device;
• capturing a microphone signal on a basis of the excited gas using a microphone;
• and
• testing the gas-tightness of the sensor cell based on the microphone signal.

A photoacoustic sensor, comprising:

• a hermetically sealed sensor cell filled with a gas;
• a gas excitation device to thermally, optically, or acoustically excite the gas;
• a microphone to output a microphone signal that is based on the excited gas;
• and
• a testing unit to use the microphone signal as a basis for testing a gas-tightness of the sensor cell.