People use tape measures to inspect the general size of objects, since the tool cannot measure tolerances tighter than 1/32-inch, or about 0.031-inch, with any degree of accuracy. While tools with tighter resolutions make better inspection devices for small tolerances, the quick and useful nature of tape measures means they are found in workshops and toolboxes around the country. Tape measures should be verified and calibrated periodically if the tool is used to make any final or critical measurements.
Slide out the first foot of tape. Inspect the body of the tape measure, the tape itself and the tabbed metal clip on the end of the tape for damage.
Grip the end of a calibrated steel rule with the metal clip. Slide the tape measure open along the length of the steel rule.
Check that the measurement lines on the tape measure align with the measurement lines on the calibrated steel rule.
Gently bend the metal clip on the end of the tape measure to alter the location of the grip and align the tape's measurement lines with the steel rule if necessary.
Stop using a tape measure that cannot match a calibrated steel rule. Repeat the procedure periodically to ensure the tape measure maintains its accuracy.
Company or personal procedures determine how often to check the calibration of a tape measure. Always check the calibration of a newly damaged or dropped tool prior to using it. If tape measure are used simply as a reference tool in a workplace environment, and take no final dimensions, label them as such to avoid performing unnecessary calibration procedures.