| 摘要 |
A mineral insulated thermocouple cable is inserted into a cover tube. The cover tube is sealed shut beyond the end of the thermocouple hot junction. The void within the cover tube in and around the thermocouple hot junction area has a heat conductive filler such as a boron ceramic preform or even some liquid mercury. The tube is filled with an inert gas such as argon, pressurized from a gas source and connected to a negative pressure alarm or gauge for detecting pressure loss. When there is an escape of gas from the tube, indicating penetration of the gas tube wall by corrosion, thereby causing a reduction in pressure in the gas tube, the reduction in pressure is observed at the gauge, or it triggers the alarm.
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