A gas detector comprising a sensor (100) configured to detect the oxygen content in the ambient air around the gas detector; a housing configured to seal around a portion of the sensor, creating a hermetically sealed interior of the housing while exposing at least a portion of the sensor on the exterior of the housing; and a pressure equalizing element (112, 114) located between the exposed portion of the sensor and the hermetically sealed interior of the housing, configured to allow pressure equalization of the sealed interior of the housing.