Microwave probe and rotary body detecting apparatus using the same

摘要

A microwave probe has a cylindrical support made of stabilized zirconia being excellent in heat insulation, and the cylindrical support is threadably installed at a partitioning wall to partition an atmosphere of high temperature. The support is provided at the center with a through hole, and an antenna for transmitting or receiving microwave is installed at one opening of the through hole positioning at outside of the partitioning wall, and a metal ring member is installed at other opening of the through hole positioning within the partitioning wall. The transmitting and receiving antenna and the ring member are fixed to respective openings by a ceramic adhesive which is filled in the through hole and excellent in heat insulation. A part of the ring member projects in the atmosphere. A rotary body breakage detecting apparatus has the microwave probe installed at a cabinet wall to cover a wing body rotating in an atmosphere of high temperature, and a microwave oscillator and a microwave detector are connected to the probe through a circulator. A breakage detecting circuit is connected to the microwave detector. The breakage detecting circuit detects that peak value of the receiving signal outputted from the detector (the signal pulsating with rotation of the wing body) varies beyond a prescribed range, and generates signal informing the breakage of the wing body.