Gas station pumps are regulated under each individual state's government by a bureau or division centered on standards and weights. They are responsible for keeping the sale of gasoline fair for consumers.
Inspections are routinely done throughout the year for retail gasoline stations. Tests are employed to check calibration of the pumps to ensure a fair meter count and quality of the product.
A consumer hot line is in place to take all comments and complaints about individual retailers so inspectors can respond to any problems that arise between inspections.
The use of undercover vehicles to test gas pumps is also a technique that the standards bureaus employ. The gas tank on the undercover inspector's car is engineered to test the amount of gas filling the area to verify any calibration issues with the pump itself. The service attendant would not know the difference between the tester's car and a typical customer, making this testing device successful in keeping gas stations honest in their calibrations.