MONITORING APPARATUS FOR SOOT OR THE LIKE

PROBLEM TO BE SOLVED: To obtain a monitoring apparatus which is installed easily at a site and by which soot, dust or the like can be detected precisely and quickly, by a method wherein the soot, the dust or the like which is generated or stays in a prescribed space position is irradiated with light, and the brightness of a screen imaged by an imaging means is compared with a threshold value. SOLUTION: A melting furnace 2 which is installed on a floor 1 discharges soot G or the like upward from its furnace top 4, and the discharged soot G or the like rises so as to stay in a space 8 which is sandwiched between a building 6 and the furnace top 4. In this monitoring apparatus, the soot G or the like is irraidated with light L, it is imaged by a CCD camera 14, and an image is sent to a controller 16. In the controller 16, the light is converted into an electric charge by a CCD element, and every pixel is decided as a bright pixel which displays the soot G or the like irradiated with the light L or as a dark pixel which displays the space 8. Then, the brightness of every pixel in a screen is compared with a preset threshold value. When the total number of dark pixels at the threshold value or lower becomes a preset value or lower, an electric signal is outputted.