POWDER DETECTING DEVICE

PURPOSE:To accurately detect the dispersed state of powder while the powder is transported by finishing the external periphery of a transparent pipe for transporting the powder to a mirror surface and respectively providing a light source and light receiving section at both ends of the pipe. CONSTITUTION:A mirror surface section 2 is formed by metal vapor deposition, etc., on the external peripheral surface of a transparent pipe 1, such as a glass pipe, etc. In addition, a light source 3 and light receiving section 4 are respectively provided near the entrance 7 and exit 8 of the pipe 1. When powder is transported through the pipe 1 by producing a stream in the direction shown by the arrow A from the entrance 7 side to the exit 8 side and a laser beam is emitted from the light source 3, the laser light is reflected by the internal surface of the section 2 and made incident to the section 4, with the quantity of the light made incident to the section 4 being changed due to the interception of the powder carried by the stream. The change in light quantity is converted into a change in voltage by means of the section 4 and sent to a voltage displaying section 6 after the change in voltage is amplified by means of an amplifier 5. When the change in voltage displayed on the section 6 is watched, the dispersed state of the powder in the stream can be detected.