초록 ▼

Method and device for monitoring a moving web, such as a wire in a paper machine, a felt, or a material web, such as a board or paper web. A bar of radiation beams is directed at the face of the web to be monitored by a series of transmitters in a direction transverse to the direction of movement of

Method and device for monitoring a moving web, such as a wire in a paper machine, a felt, or a material web, such as a board or paper web. A bar of radiation beams is directed at the face of the web to be monitored by a series of transmitters in a direction transverse to the direction of movement of the web. Radiation reflected from the web and the background is detected by a series of receivers. The measurement signals obtained in this way are passed to an electronic unit in which a quantity that characterizes the monitoring of the web is determined from the measurement signals. The approximate location of the edge, the edges, or of corresponding discontinuities of the web is detected “digitally”on the basis of the radiation beam of the radiation transmitter in whose area the greatest change takes place in the received radiation. The precise location of the edge or equivalent of the web to be monitored is determined analogously by comparing the amplitudes of the signals of the adjacent receivers placed closest to the last-mentioned radiation transmitter with one another.

대표청구항 ▼

A method for monitoring a moving web, comprising the steps of: arranging a series of transmitters to direct a bar of radiation beams at a face of the web in a direction substantially transverse to a direction of movement of the web, arranging a series of receivers to detect radiation reflected from

A method for monitoring a moving web, comprising the steps of: arranging a series of transmitters to direct a bar of radiation beams at a face of the web in a direction substantially transverse to a direction of movement of the web, arranging a series of receivers to detect radiation reflected from the web and background, passing measurement signals corresponding to the detected radiation from said series of receivers to an electronic unit, determining a quantity in said electronic unit from the measurement signals that characterizes the monitoring of the web, determining digitally an approximate location of an edge or a corresponding discontinuity in the web on the basis of the largest change in reflected radiation detected by said series of receivers in an area of one of said series of transmitters, and determining analogously the precise location of the edge or corresponding continuity of the web by comparing values of the measurement signals of adjacent ones of said series of receivers situated closest to said one of said series of transmitters.