Device and method for operating a heatable sensor in an explosive atmosphere

A method for operating a heatable sensor in an explosive atmosphere, the method comprising:

• providing, in a measurement volume, an encapsulation device for a heatable sensor, the encapsulation device comprising:
• a receiving space designed to receive the heatable sensor,
• a protective housing having at least one gas-permeable wall portion that permits gas exchange between an interior space of the encapsulation device and an environment of the encapsulation device through the gas-permeable wall portion,
• a quenching volume arranged to extend along an inner side of the protective housing and filled with a filling material, the quenching volume at least partially surrounding the receiving space, the encapsulation device being configured to distribute and dissipate heat released from the heatable sensor in such a way that, under the intended operating conditions, a highest surface temperature at an outer side of the encapsulation device is lower than a highest surface temperature of the heatable sensor, and
• a gas-permeable filter element, which is disposed between the quenching volume and the receiving space and bounds the quenching volume with respect to the receiving space;
• providing the heatable sensor in the receiving space of the encapsulation device;
• and
• energizing the heatable sensor with electrical power, the electrical power being selected such that it is greater than a power limit for intrinsic safety as the type of ignition protection with respect to the heatable sensor, and such that the highest surface temperature at the outer side of the encapsulation device is lower than a temperature limit for explosion protection with respect to the heatable sensor.