Apparatus for determining any contamination of dust, etc., in a duct prior to cleaning the duct

An apparatus for searching for any contamination of an inside surface of a duct, comprising:

• a traveling truck;
• a driving means for driving said traveling truck forwardly and backwardly in an interior of said duct (1) whose inside contamination is to be investigated;
• a monitor video camera (5) positioned on said traveling truck (3) for monitoring an inside view of said duct (1);
• a remote monitor image display means (6) for displaying an image taken by said monitor video camera;
• a transceiver (9) for transmitting radio signals from and to said remote monitor image display means and via a connecting line (13) from and to said video camera;
• at least one compressed air ejecting nozzle (50) provided on a forward end of said traveling truck for ejecting compressed air toward inside surfaces of said duct firstly to permit an examination by said video camera whether any dust has accumulated on said inside surfaces of said duct and is capable of being blown off by said compressed air, and secondly to expose the inside surfaces of said duct for viewing by said video camera by blowing off said dust;
• an air compressor for supplying compressed air to said at least one compressed-air ejecting nozzle via an air transmission tube (14);
• an electromagnetic control valve in said air transmission tube for controlling the compressed air supplied to said compressed-air ejecting nozzle;
• an electronic circuit connected with said transceiver for controlling said driving means, said monitor video camera and said electromagnetic control valve,
• a remote control for controlling said remote monitor image display means and said transceiver;
• whereby the inside contamination of said duct is made clear both by determining if any dust accumulated inside the duct is capable of being blown off and by observing underlying contamination appearing on the inner surfaces of the duct if the accumulated dust has been blown off.