ABSTRACT
In order to learn how to read a rule, carefully study the rules shown in Figure 3.1 and the enlarged portion of a rule depicted in Figure 3.2. Practice making measurements with a variety of steel rules on known NIST
standard blocks (see Figures 3.3 and 3.4) until you become proficient. Figure 3.5 shows a NIST-traceable gauge block standard with its serial number and certified dimension marked on its front surface. The use of the NIST-traceable standard blocks and rules also serves to calibrate the accuracy of the rulers being used to make the measurements.
