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Welcome to our new and updated site. Browsing through the site you will find information on mass and liquid measurement as well as discussions on many of the latest consumer measurement issues. Take a look at our ever popular and expanding calculators & conversion sections.

We have just added sections on calibrating open neck provers and made available our Gravimetric Proving Worksheet. Also now available is the H2O density reference book and an open neck proving worksheet. There is so much to see, please look around and don't hesitate to contact us with your comments or to enquire about your custom metrology software needs.

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Tare Weight

Should I pay for the packaging? Do you know what a tare weight is? If you purchase items in packages by weight you should. Tare weight is the package or container weight and you don't want to be paying for it!.

When you take a package from your kitchen and it has a weight marked on it, the weight must be Net weight. Net Weight is equal to the Total weight of the package and contents minus the Tare or package weight. Prepackaged items are seldom incorrect as the automated packing machines ensure that adequate tare is taken. Items which are packaged within a store should have proper tare allowances made as well, however mistakes are sometimes made.

Gross Weight = Tare Weight + Net Weight
Net Weight = Gross Weight - Tare Weight

Packages of meat contain soakers, plastic wrap, trays, labels, etc. All of this is to be considered Tare weight. You don't want to pay T-Bone Steak prices for plastic wrap. If you purchase items at the bulk food counter, ensure that the procedure used accounts for the weight of the package. This is especially important when the container is a heavy plastic tub with a lid. Most self serve bulk food stores will have explicit instructions posted. Follow them carefully as they are designed to ensure you receive accurate net weight. You can double check your purchase as well. Weigh the container (and the lid) before filling with your item. Complete your purchase and print the label. Place the entire item back on the scale. The total weight should be equal to the Net weight printed on your label plus the original weight of the container. If the weight on the label is equal to the total weight of your purchase, in it's container, you are paying for the container! It is more difficult to check meat products which are prepackaged at the back of the store and then scanned at the checkout. You can however place the package of meat on the front end scale and ensure that the weight on the label (Net weight) is less than the total (Gross) weight of the package. While this will not tell you if the store allowed the correct Tare weight, it will at least confirm that they have taken some tare.

Many scales, especially those at deli counters, etc. will take tare automatically. If you're not sure, ask the clerk if tare was taken. If they don't know what tare is, ask for a manager. Pay careful attention to specialty items as the stores often don't have the tare information available to them or will simply forget to enter this information into their systems.

Last modified: 22 June 2009 15:37:53