Consumer Affairs

Inspection of Length-Measuring Devices
Information Sheet No. 9

Every fabric-measuring device, wire/cordage-measuring device, and linear measure used to sell products in the city of Seattle must be tested and approved by weights and measures inspectors from the Consumer Affairs Unit [Seattle Municipal Code, Section 7.04.145]. Weights and measures inspectors will affix paper approval seals on or adjacent to those devices approved for commercial use. Use of a length-measuring device that hasn’t been approved is a criminal misdemeanor punishable by fine and/or imprisonment [SMC 7.04.690].

Inspection and test procedures for length-measuring devices are contained in Handbook 44 Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices (1997) published by the National Institute of Standards and Technology (NIST). Handbook 44 has been adopted for use in the city of Seattle [SMC 7.04.140]. The applicable sections are:

Section 5.50 Fabric-Measuring Devices Section 5.51 Wire- and Cordage-Measuring Devices Section 5.52 Linear Measures

Fabric-Measuring Devices. A device that won’t accurately measure all fabrics must be marked to clearly indicate its limitations. Inspectors will use a cloth testing tape 12 yards in length to test the accuracy of the fabric-measuring device. The tolerance for fabric-measuring devices in commercial use are approximately 1/16-in. per indicated yard on overregistration (shortage) and 1/8-in. per indicated yard on underregistration. The tolerance for new or repaired fabric measuring devices is half these amounts.

Wire- and Cordage-Measuring Devices. A wire- or cordage-measuring device must only be used to measure materials it was designed to measure. Inspectors will require that material be pulled through the device and marked. The material will then be measured with a steel tape. The tolerance for wire- and cordage-measuring devices in commercial use is approximately 1-in. per indicated 10 feet on overregistration (shortage) and 2-in. per indicated 10 feet on underregistration.

Linear Measures. Usually wood or metal yard sticks or tape measures. The tolerance for linear measures (other than metal tapes) in commercial use is approximately 3/16-in. per 6 feet. The tolerance for metal tapes is approximately ¼-in. at 100 feet.

Weights and measures inspectors will conduct unannounced inspections of all length-measuring devices in commercial use. Devices found to be outside of tolerance will be rejected and may be condemned [SMC 7.04.165] and "stop use" orders may be issued [SMC 7.04.160]. Condemned length-measuring devices that are used for commercial purposes are subject to seizure and the users may be charged with criminal misdemeanors. The presence of length-measuring devices in locations where buying and selling is carried on is considered presumptive evidence that they are being used [SMC 7.04.695].

The Consumer Affairs Unit is available to answer any questions you may have regarding the requirement to use approved length-measuring devices.