摘要 |
To permit efficient heat transfer from a carrier tube (22) surrounding a tubular solid electrolyte body (11') having outer and inner electrodes (14, 18) applied thereto, the tubular heater element carrier body (22) supports a wire or resistance track heating element (25) at the inner surface thereof, the heater element (25) being spaced from the outer surface of the solid electrolyte tube (11') forming part of the sensor element (11) by a distance at the most of 1 mm, preferably less than 0.5 mm, the wall thickness of the heater element carrier tube (22) preferably being between 0.3 and 0.8 mm thick, the carrier tube being made of ceramic, such as aluminum oxide, or internally insulated metal. |