| 摘要 |
PURPOSE:To measure the position of a liquid level highly accurately without the effect of the vibration of the liquid level by providing an opaque structure on the liquid surface, picking up the mirror image of the structure which is projected on the liquid surface with one- dimensional or two-dimensional camera, computing the coordinates of the edge part of the mirror image within the field of view of the camera, and obtaining the position of the liquid level. CONSTITUTION:A rod-shaped structure 29 is provided at a position which is higher than the liquid level of fused liquid 11 by about 10mm. The structure is fixed at the upper surface of a furnace body. A mirror image 30 of the structure, which is projected on the liquid surface of the fused liquid 11, is picked up with a two-dimensional camera 31. The image signal is outputted into an image processing device 33. The device 33 detects the edge part of the mirror image 30 and outputs the part into an operating device 34. The device 34 converts the part into the position of the liquid level. The position is displayed on a liquid- level-position display device 35. A light reducing filter 32 is attached to the camera 31, and the heat radiation light from the fused liquid 11 is attenuated. Thus, the vibration of the position of the mirror image with respect to the vibration of the liquid level is reduced, and the position of the liquid level can be measured highly accurately. |
