Weights & Measures Frequently Asked Questions


This is the most common question we receive. The short answer is that all tanks are not created equal. The stated capacity of your gas tank in your owner's manual or stamped on your gas can is more an approximation than a fact. A major manufacturer may buy fuel tanks from a variety of suppliers, all of which may hold either a little more or a little less than the stated capacity. Also, the volume of fuel contained in the filler tube will vary. In almost every instance when we retest the pump in question, it is found to be within tolerance (+/-.025 gal. for every 5 gal. dispensed). Even so, the Office of Weights and Measures will investigate all instances if you file a complaint.

Verify that the advertised sign and the pump price are the same. Make sure the pump starts at zero. Know an estimate of what the capacity of your gasoline tank is. Make sure a current Weights and Measures seal is visible on the pump.

Yes. It is not wise for the station owner to put them together, but as long as they are labeled properly, you are responsible.

Yes. It is commonly understood that you assume the responsibility and liability for refueling your own vehicle. It is wise to remain close if you are using the automatic shut-off valve to stop the pump just in case there is a malfunction.

Ask the station attendant or owner to test the tank for water by putting water-finding paste on the end of the dipstick, then lower the stick into the tank. If there is water in it, it will turn the paste a different color (usually purple), and there will be a definite line where the water is. Remember to test the water-finding paste by putting a little water on it before sticking it into the tank. If you have any problems, contact us or call (605) 773-3697 immediately – do not wait. The longer you wait, the less we can do to help.

If you suspect you have gotten contaminated gas, you can also file a complaint for investigation.

If your business buys or sells any commodity or service by weight, you are required to have an approved, "Legal for Trade" device.

A "Legal for Trade" scale is one that meets the requirements of National Institute of Standards and Technology (NIST) Handbook 44 and is approved by the National Type Evaluation Program (NTEP). "Legal for Trade" devices will have an accuracy class designation, the most common being class III or III L. This designation will be on the scale, usually on the serial plate.

South Dakota Codified Law prohibits commercial transactions utilizing a weight or measure or a measuring or weighing device that has not been sealed by the Office of Weights and Measures within two years. An inspector in your area will inspect and verify accuracy and suitability for continued commercial use. Inspection frequency varies by the type of device. Gasoline pumps and retail scale inspections are every two years, and heavy scale inspections are normally conducted annually.

A registered scale company may charge a fee for this service or include the service when you purchase a scale from them. The Office of Weights and Measures charges inspection fees to inspect the device once installed.

Any type of deli item must be sold on a net weight basis. Selling a product by gross weight (net weight plus tare weight) is illegal. The weight of the container is called "tare" and is not included in the net weight. Almost all scales now in use at deli counters are of the digital computing type and show the weight of the product, the price per pound and the total selling price on a digital display that faces the customer.

Additionally, most stores assign a store code to each item. Information included in this code, which is stored in the scale, contains the name of the item, the price per pound and the correct tare weight for the container that should be used. So when you want to purchase an item, the counter person will enter the store code for your item, the display panel will show the selling price, and the weight display should show a negative number which represents the container or tare weight being zeroed off the scale. If you do not see this negative number displayed when the code is entered, report this to the Office of Weights and Measures.

Make sure the device is on a level surface and that you can see the display. The instrument must start at zero. There should not be anything touching the device. Watch the person doing the weighing or measuring to make sure that nothing extra is added. Verify that there is a current Weights and Measures seal on the device.

The best way to avoid being overcharged is to make a list of all the items you are going to purchase, and write down the shelf prices. Compare the prices you wrote down to the prices you are charged. If there is a discrepancy, notify the cashier. If the cashier does not change the price, talk to the manager about your dilemma. If the manager cannot or will not change the price for you, contact the Office of Weights and Measures.

No. A scale intended to be used commercially must first be tested and "placed in service," then sealed by a State inspector. The device is required to be tested and placed into service by the State. 

You should contact a scale repair company (registered service agency) if you suspect there is a problem with your device. Scale repair agencies are usually listed in a local phone directory or yellow pages. The Office of Weights and Measures does not repair scales; however, we can provide the names of registered scale repair agencies in your area.

The Office of Weights and Measures has adopted National Institute of Standards and Technology (NIST) Handbook 133 as the procedure for testing the net contents of packaged goods. Learn more about labeling and packaging.

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