The stakes are greater in larger states, and nationally they could add up to a staggering $7 trillion.
Earlier this year, more than a dozen states uncovered a pattern of fish packers adding the weight of glaze ice to the labeled weight of fish, meaning consumers ended up paying several dollars more per pound of fish.
There's no proof such scams are related to the recession but authorities say unscrupulous businesses are more likely to cheat when states cut back on enforcement.
Correct weights affect the formulations of medicines, baby formulas, the chemicals in toothpaste, foods and liquids people eat and drink. Americans depend on accurate measurements when they fill their gas- or heating-oil tanks, buy meat at the butcher counter, pay taxi fares or purchase a gallon of milk.
The National Institute of Standards and Technology, a non-regulatory federal agency and lead standards-setting organization for the country, says its work to advance an accurate measuring system underpins about half the U.S. economy, or about $7 trillion of the U.S. gross domestic product.
"As dollars become tight, it's more important than ever," said Carol Hockert, chief of NIST's Weights and Measures Division. It's important not just to consumers, who assume they are getting what they pay for, but also to businesses that need to know they're competing on a fair basis and aren't giving customers more than they paid for.
Ensuring the accuracy of weighing and measuring devices all comes down to obscure shops like Newcombe's, a flat, brick building that houses precisely scaled weights starting at 1 milligram -- roughly the size of the tip of a ball point pen -- to huge 1,000-pound blocks that are used to make sure roadside truck scales are exactly right.
A small team of five inspectors from the Maine Agriculture Department's weight and measures program fan out across the state with their precision testing devices to ensure the accuracy of scales, pumps and containers that measure out goods sold at wholesale and retail levels.
Their work takes them from bakeries and butcher counters to fuel-storage facilities and paper mills. They check milk tanks at dairy farms and package scales and scanners from supermarkets and department stores to make sure prices are correct, said Newcombe.
Questionable firewood measurements trigger many of the complaints in Maine, said Steve Giguere, deputy state sealer of weights and measures. In the fall of 2008, inspectors found more than 90 percent of the complaints to be valid, a much larger percentage than the 8-10 percent of the gas pumps and small retail scales that fail.
With a limited field staff, the Maine inspectors end up spending half their time responding to complaints. That's the trend across the country, as cash-strapped states find less and less money for inspections.
"States are more reactive, not proactive," said Steve Dishon of the International Society of Weighing and Measurement, the trade association for weighing and measurement industry professionals. "They react to whoever squawks the loudest."
In the case of the frozen fish scams, The U.S. Food and Drug Administration sent letters to two Illinois companies in October and February, threatening action over labeling issues. Wisconsin and New York have said they may take enforcement action. In Fairfield County, Ohio, two local retailers found to be selling fish at the wrong weight were assessed $500 per store.
Dishon, who's been in the business for 32 years, said the biggest causes of discrepancies are flaws in electronic transferal of data in modern-day devices. And hospitals, which are full of scales and other measuring devices, have the most discrepancies, he said. Hospitals often hire private companies for periodic checks of devices.
Plenty of errors turn up elsewhere.
A surprise inspection in 2008 at Phoenix Sky Harbor International Airport found that 28 of Southwest Airlines' 72 baggage scales were slightly out of calibration, while three others had more serious problems and were shut down until they were fixed. At US Airways, 25 of 46 scales had minor problems. Accurate weights are important now with airlines charging extra fees for bags weighing over 50 pounds.
The good news -- for consumers, anyway -- is that scales found to be out of compliance generally were off in the passengers' favor.
But sometimes consumers lose.
Office Depot Inc. agreed in 2007 to pay $2.3 million to settle a lawsuit claiming that California customers were overcharged by faulty scanners at the checkout line. Office Depot did not admit any wrongdoing in the settlement.
Also in 2007, the Texas Agriculture Department published on its website a list of 100 gas stations whose inaccurate fuel pumps were shortchanging drivers in the state. The same year, inspections in Minnesota turned up a gas station where customers were getting about 4 1/2 gallons of gas for every 5 gallons they paid for.
While it's only a guess how much money consumers and businesses win or lose because of skewed scales, Newcombe's calculations give a hint. Advanced technology that enabled Maine to change the way it measures liquid density revealed a 0.024 percent error. When you add up the difference it made in sales of motor and heating fuels, the total impact was $4.8 million -- to the benefit of consumers in Maine, New Hampshire, Vermont and Massachusetts.
In 2007, Wisconsin inspections over the previous two years showed a gas pump failure rate of about 3 percent. But they also turned up a bad pump that gave drivers four gallons of extra gas for every 15 they bought, and one showing customers lost about a half gallon for every 15 gallons purchased. ------
National Conference of Weights and Measures: www.ncwm.net
National Institute of Standards and Technology: www.nist.gov
International Society of Weighing and Measurement: www.iswm.org