Witness Testing in Official Weights and Measures Inspections

Witness Testing in Official Weights and Measures Inspections

Weights and measures inspections provide a legally required, independent validation of the accuracy of commercial weighing and measuring devices; provide a level playing field for competing businesses; and help ensure consumers get what they pay for and businesses receive accurate payment for the goods and services they sell. But what happens when weights and measures programs lack the necessary standards and equipment to conduct verification tests on a particular type of device? Do such devices simply go unregulated? How does this impact consumers and businesses that rely on the assurances provided by official inspections? The practice of “witness testing” provides a solution to help ensure protections for consumers and businesses alike.


Emerging technologies such as commercial electric vehicle chargers and other alternative fuels sometimes require specialized test standards or equipment to carry out adequate testing to ensure marketplace protections and verify compliance with weights and measures laws and regulations. Even applications that are not “emerging” or “unique” may pose a challenge for routine inspection and testing when test standards are not readily available to or practical for a weights and measures jurisdiction to obtain. Many jurisdictions have long employed the practice of “witness testing” as an efficient approach for testing applications such as large metering systems, railway track scales, belt-conveyor scales, automatic bulk weighing systems, or even prepackaged commodities.


This article describes the concept of witness testing, factors that lead to its use and associated benefits, and approaches that can be used by weights and measures programs to effectively use the practice to conduct an official weights and measures inspection and test. This article is the first in a short series of articles designed to highlight the elements of witness testing and help jurisdictions expand its use.


What is Witness Testing?


Witness t ..

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