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WDA Weights and Measures Lab Continues Inspections Benefitting Consumers

Written by Robert Weidler

By Robert Weidler, Wyoming Department of Agriculture


Several divisions comprise the Wyoming Department of Agriculture (WDA). Technical Services (TS) is among these. TS is responsible for a wide variety of programs, but one that benefits all Wyoming producers and consumers is Weights and Measures.

Weights and Measures inspectors throughout the state inspect and test a wide variety of devices for accurate performance and compliance to specific standards. These inspectors use equipment that has been calibrated to accuracy levels of approximately 0.01 percent. An example of this is a 1000-pound test weight used during livestock scale inspection. The test weights used are calibrated for accuracy of plus or minus 0.1 of a pound.

To keep test equipment in good working order and ensure accuracy levels are maintained, TS is equipped with its own metrology laboratory. Metrology is the science of measurement, and the lab, located in Cheyenne, offers mass and volumetric calibration services for all WDA inspectors. In addition, the lab offers the same service for industry technicians that install and repair weighing and measuring devices. To ensure the laboratory is providing credible measurements it maintains recognition – a form of accreditation – from the United State Department of Commerce National Institute of Standards and Technology (NIST). The process of securing recognition is quite rigorous and the lab participates in proficiency testing throughout the year. Additionally, the lab submits an annual application packet to NIST for evidence of quality control and proper procedure.

The WDA Weights and Measures Lab has worked hard in recent years to expand its scope of accreditation to meet the needs of customers. Workload for the year 2014 increased for all calibrations. The lab performed a total of about 1,465 calibrations in 2014. This is the highest number performed and is a significant increase over any previous year.

The majority of the workload, about 96 percent, is mass calibration and weights ranging from 0.001 pounds, or small scale inspection, to 3,000 pound, or coal mine hopper weights. Including calibration of railroad test cars, the lab calibrated somewhere in the neighborhood of several million pounds of test weights. Volume workload makes up the remaining four percent and refined fuel volumetric provers from five-gallon gas pump inspection to 1,000-gallon refinery loading rack inspection were calibrated. Additionally, the volumetric workload includes calibration of Liquefied Petroleum Gas (LPG) provers from 25 gallon propane bottle dispenser inspection to 100 gallon propane delivery truck inspection.

Since obtaining recognition by the NIST in 2009, the lab has worked to expand its scope and offer additional calibration services. This has resulted in a wider variety of calibration services for industry technicians. Approximately 70 percent of lab customers are private technicians that work to repair and calibrate weighing and measuring devices. The remaining 30 percent is the WDA TS inspection staff.

In addition to serving technicians that reside in Wyoming, the lab is becoming a regional presence. During 2014, calibrations for technicians from Montana, South Dakota, Colorado, North Dakota, Nebraska and Utah were performed. Many of these technicians serve customers in Wyoming and come to the WDA lab because it offers services that are not available in their state.

The largest increase in calibration type includes items that have been added to the lab’s scope in recent years. Major increases in 2014 include LPG prover calibration, which increased 120 percent, large mass used in the mining industry, up 100 percent and motorized test carts used for livestock and vehicle scale inspection, which were also up 100 percent.

Using accurate and traceable test equipment while inspecting or repairing weights and measures devices is critical. Maintaining NIST recognition requires considerable effort. The WDA Weights and Measures Lab is an active participant with NIST and looks to offer additional calibration services each year. By ensuring that quality measurements are issued when test equipment is calibrated, producers and consumers in Wyoming can have confidence in the WDA Weights and Measures Inspection Program.