Weights & Measures


The Office of Weights and Measures has compiled a list of most Frequently Asked Questions and answers to those questions. For additional information, please refer to the Contacts section to mail, e-mail, fax or telephone any additional questions.



Q. I filled up at the gas station yesterday and put 15 gallons of gas in my tank. However, when I got to the station, my fuel gauge still was on 1/4 of a tank and my owner's manual says the tank only holds 16 gallons. How can this be? Or, I bought a new gas can the other day at the local hardware store.  It's supposed to hold five gallons, but I got less than 5 gallons in it. I think the pump must be in error.

A. This is the most common complaint we receive, and the short answer is that all tanks are not created equal. The stated capacity of your gas tank in your owner's manual or what's stamped on your gas can is often more of 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 complaints received. For a detailed explanation of why the pumped volume of fuel may be greater (or less) than the rated capacity of your automobile gas tank, refer to the following article in the August 2005 NIST Weights and Measures Quarterly. read article (pdf)


Q. What steps can I take to prevent being cheated at a gas station?

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


Q: If a gasoline pump and a diesel pump are right together and I inadvertently put diesel fuel in my gasoline tank or visa-versa, am I responsible?

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



Q: Am I responsible for the gasoline that is spilled on the driveway because the automatic shut-off valve on the nozzle did not shut off?

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



Q: What do I do if I suspect that there is water in the gas or the gas is bad?

A: Ask the station attendant or owner to test the tank for water by putting water-finding paste on the end of the dip stick, 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, call Weights and Measures at 605.773.3697 immediately.  DO NOT WAIT!   The longer you wait, the less we can do to help.



Q. Do I need a commercial scale which is approved and Legal-for-Trade in order to conduct business?

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

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Q. What constitutes a "Legal-for-Trade" scale?

A. A "Legal-for-Trade" scale is one which 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.



Q. How long is a weighing or measuring device approval valid when sealed by the Office of Weights and Measures?

A. South Dakota Codified Law prohibits commercial transactions utilizing a weight or measure or 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 test the device periodically to determine its accuracy and suitability for continued commercial use. Inspection frequency varies by the type of device. Gasoline pumps and retail scales inspections are every two years, and heavy scales inspections are normally conducted annually.



Q. Is there a fee for testing new scales and placing them in service?

A registered scale company may charge a fee for this service, or include the service when you purchase a scale from them. Office of Weights and Measures fees to inspect the device, once, installed, are detailed in the Weights and Measures Device Inspection Fees section.



Q. When I buy products at the deli counter, am I paying for the container? How would I know?

A. 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, the customary practice in most stores is to 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 which should be used. So when you want to purchase an item, the counter person will enter the store code for your item and 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, you may be paying for the container and should report this to the Office of Weights and Measures.

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Q. What steps can I take to prevent being shorted on a weighing or measuring device?

A. 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.



Q. How can I avoid being overcharged at the register?

A. 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.



Q. What should I do if I am overcharged?

A. 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.



Q. Can I use my new scale for commercial transactions right out of the package?

A. No. A scale intended to be used commercially must first be inspected and approved by a state inspector or tested and "placed in service" by a registered scale service agency.



Q. If I have a problem with my scale, whom should I contact?

A. 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.

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Q. My business produces commodities sold in package form. What are the requirements for net contents compliance?

A. 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.



Q. What countries besides the U.S. have not adopted the metric system?

A. All countries have adopted the metric system, including the U.S., and most countries (but not the U.S.) have taken steps to eliminate most uses of traditional measurements. However, in nearly all countries people still use traditional units sometimes, at least in colloquial expressions. Becoming metric is not a one-time event that has either happened or not. It is a process that happens over time. Every country is somewhere in this process of going metric, some much further along than others.


Q. What are the dimensions of a cord of wood?

A. 128 cubic feet. Stack your wood neatly by placing the wood in a row, with the pieces touching and parallel to each other, and with as few gaps as possible. Multiply the length times the width times the height of the stack. If this equals 128 cubic feet, then you have a cord of wood. Common measurements of a cord of wood are 8 feet by 4 feet by 4 feet or 16 feet by 2 feet by 4

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