A size checking apparatus is employed to check sizes or dimensions of a work. The size checking apparatus includes: a constant speed transporting unit for a work; a measuring unit for continuously measuring a distance from a measurement sensor to a measuring position of the work while the work is being transported; a trigger signal generator for sensing that the work has passed and for commencing an acquisition of a measurement value by the measuring unit in response to a trigger signal; a pulse signal generator for generating a pulse signal in synchronism with the transportation of the work; an average value holding circuit for holding, in a time sequential mode during one cycle, an average value of the measurement value; an upper limit data holding circuit for holding an upper limit value; a lower limit value data holding circuit for holding a lower limit value; a calculation processing unit for setting an allowable range and for outputting a defect signal when the measurement value deviates from the allowable range; and a connection unit for a computer for setting the quantity of works to be measured, a measuring time period and a measuring number in the calculation processing unit, for setting the allowable range and for displaying the allowable range and the waveforms of the measurement values.
A method of displaying continuously acquired measurement data in a display with a fixed number of pixels is provided. Measurement data is provided at a predetermined fixed sample rate independent of a pixel rate which is equal to or less than the sample rate. The measurement data is convened to pixel data which includes the minimum, maximum, and the average of the measurement data gathered and the pixel data is plotted to the pixels at a pixel rate. At the end of the fixed number of pixels of the display, the pixel values are compressed to half the fixed number of pixels and the pixel rate is halved, thereby doubling the time scale. This process can continue indefinitely, requiring no operator intervention or prior knowledge to set a total measurement time. Furthermore, the sample rate is independent of the pixel rate so that a tradeoff of sample rate and total measurement time need not be made.
A feed-through dimensional measurement system for gathering crossectional measurement data from an elongated part and correlating that data with the longitudinal position on the part from which the data was measured. The system includes a measurement apparatus supported on a part support stand having measuring instruments coupled to a central processing unit for recording and correlating the measurement data. A part drive system drives the part through a transport zone on the support stand while a clamping roller module holds the part against two orthogonal planes established by a set of rollers in the transport zone. Web thickness is measured in relation to a vertical reference plane established by one set of the rollers, and part height and warpage is measured with reference to the orthogonal reference plane. A flatness measurement module and a flange width measurement module provide additional digital dimensional signals to the central processing unit that is programmed to store the measurement data and to graphically display the measured dimensions in relation to the part's designed dimensions.
