Abstract: A contract estimating system includes a digitizer ruler divided into a plurality of equally spaced increments. The ruler generates an output signal representing the distance along the ruler at a point touched by a hand held probe. A digitizer board carries a menu thereon including a plurality of indicia such as words, pictures and numbers representing different component parts and sizes and scale factors and generates an output signal corresponding to one of the indicia when touched by the probe. A computer automatically counts the number of each size component part and calculates the total length of pipes and similar components measured by the ruler. The results calculated by the computer can be displayed on a CRT and/or printed on a printer.

Abstract: A bar code ruler is divided into a plurality of equally spaced increments each of which is marked by a machine readable bar code number. The ruler includes a plurality of recesses along the length thereof which cooperate with a spring biased ball carried by a slide member, the ball and recesses functioning as a detent to temporarily maintain the slide member in any desired position on the ruler. A hand held bar code reader is used to scan the bar code number on the ruler next to the slide with the edge of the slide functioning as a guide. A menu is also provided which includes a plurality of bar codes representing different component parts and sizes and a plurality of scale factors. The bar code reader can read the codes on the menu and on the ruler and feeds the information to a computer which counts the number of each size component part and which calculates the total length of pipes and similar components measured by the ruler.