| 摘要 |
An apparatus 102 for determining thickness of refractory material (fig 1, 4) lining a metal vessel (fig 1, 6), comprising a gamma radiation source (116) for emitting radiation through a metal wall of the vessel and into the refractory material, wherein some of the radiation (fig 3, 30) is scattered by material, and a radiation detector 120 comprising of a scintillation crystal and photomultiplier for detecting radiation scattered (fig 3, 28) by material through the wall of the vessel. Shielding means in the form of collimators 124 and 126 attenuate the emitted radiation. A converter provides an output signal dependent on the quantity of radiation scattered by the material through the wall of the vessel and is detected by the radiation detector. A permanent magnet 146 and magnetic wheel 144 are used as attraction means for maintaining the apparatus within a predetermined distance of the vessel wall, and is used with the apparatus eyebolt (fig 2, 14) and external pulley (fig 1, 50) and winch (fig 1, 52) to traverse the metal vessel exterior during measurement. The apparatus also comprises means for circulating air through the apparatus using fans 170, 173 and air gaps 172 and 174. |
