Abstract: An instrument for auto measuring the width and length of wood board which based on the onedimensional linear array CCD（charge coupled device）sensor and computer technique is introduced. In this instrument, doublechannel linear array CCD device and electro optical system are used to measure wood board width, the measuring precision is 1 mm. The methods of lightblocked photoelectro door and computer time counting are used to measure the wood board length. The relative measuring error of length is below 1%. System liability is guaranteed with the industry pc, OEM card and antiinterference technology. User interface based on C++language are used in the program to modify parameters and improve precision. The measuring result can be sent to database and output with bar code. Changing system software properly, it is compatible for noncontact measurement of industrial products boundary dimension.

Key words: CCD（charge coupled device）, automeasuring, instrument, boundary dimension