Oxygen sensors

摘要

An oxygen sensor is disclosed, which includes a planar sensor element and a metallic cover. The planar sensor element is provided with a detecting section at least at one of outer side surfaces thereof for detecting a gas to be measured. The detecting section is protected with the metallic cover. The metallic cover is provided with gas introduction openings for introducing the gas into the metallic cover. The gas introduction openings are arranged so as not to be opposed to the detecting section of the oxygen sensor element. Guide plates are provided at the gas introduction openings, respectively for swirling the gas inside the metallic cover in a given direction. The metallic cover is provided with a gas discharge opening at the bottom face thereof.