Math and games of chance collide at the NCDA&CS Standards Laboratory
Once a month, small white balls locked in a case with their own personal security staff make their way to the Standards Laboratory in Raleigh to have their weight and diameter checked. These balls arrive at the lab with two employees that stay with them at all times, something that is usually not allowed for other customers of the lab. These balls just might be the divas of the Standards Laboratory, and it’s for good reason – the right combination makes people winners, and losers, every day.
Each month, the N.C. Education Lottery brings nine sets of the balls used for the Carolina Pick 3, Pick 4 and Cash 5 drawings to the lab to have their mass and diameter checked. Ashley Lessard, a metrologist, checks the diameter of a ball before checking its mass. The ball must easily fit through one hole, and then not fit through another, to pass the diameter check. The mass of the ball is measured and recorded. For a single set of balls the difference in mass between the heaviest and the lightest can be only .15 grams. In comparison, the mass of a dime is 1 gram. About a third of the ball sets are tested each month. These tests are done to ensure the balls have an equal chance during lottery drawings. The standards lab provides lottery officials with third-party certification that there is no more than .15 grams difference in the mass of the balls and that they pass the diameter check. The lab is also required to re-seal all of the sets of balls after they are tested and sign a log confirming chain-of-custody.
“Mass is the biggest thing companies want to get checked at the lab,” Lessard said. “The test performed on the lottery balls would be standard operating procedure 46 in our manual, or basically we are comparing the mass of the lottery balls to our standards and checking the diameter,” Lessard graduated with a masters in applied math from N.C. State University before coming to work at the lab about three years ago.
Lottery balls may be one of the more interesting things the lab weighs but certainly not the only items that are important to consumers in North Carolina. “Probably only a few industries in the state are not touched by the standards lab in some way, said Sharon Woodard, the lab’s manager. “Our lab provides weights and measures services for manufacturing companies, pharmaceutical companies, tire factories, educational facilities and more. Even the N.C. Highway Patrol uses the standards lab to test equipment; we calibrate the load cells that they use to measure the weight of trucks on our roads.” Most companies will use the lab’s services on an annual basis. The N.C. Education Lottery is one of the few customers that has a monthly appointment. Other services the lab provides include volume calibration. The large-volume provers held in a separate area of the lab allows large tanker trucks to back in to have their capacity tested. Small provers check the capacity of five-gallon gas tanks, or any other containers that need to have accurate volume levels. The lab also checks grain-moisture meters.
The N.C. Standards Laboratory is one of two labs in the state accredited by the National Voluntary Laboratory Accreditation Program (NVLAP). The other accredited lab is Transcat, a private lab in Charlotte. NVLAP is a federal program run by the National Institute of Standards and Technology that provides accreditation to labs in the United States. All employees of the lab must go through NIST training in Gaithersburg, Md., to learn fundamentals, mass and volume. “We also participate in proficiency tests a few times a year,” Woodard said. “During a proficiency test an item is circulated to accredited labs with instructions to perform various procedures on the object and mail in our results. These results are then compared to other labs for accuracy.”
The lab is currently working towards certification for precision mass and thermometers.