digital scales

  1. What is the difference between Accuracy and Precision?

    What is the difference between Accuracy and Precision?

    Accuracy & Precision: The story of the cross-bow and the apple

    We recently watched a fascinating TED Ed talk by Matt Anticole on YouTube about the difference between accuracy and precision.  Matt uses an analogy of the legend of William Tell, the Swiss folk hero.  

    William Tell was an expert marksman with a crossbow who was arrested with his son when he refused to be respectful to the King.  The King said that both he and his son would be executed, but then he King told William Tell he could save his son’s life if he shot through an apple placed on top of his son’s head.  In the legend William Tell is able to shoot the apple and save his son’s life.

    The talk considers two alternative scenarios.

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  2. Making Accurate Weight Measurements

    Making Accurate Weight Measurements

    Weighing The World

    Scales are used everyday throughout the world in a wide range of industries. From the raw material used in the products around us, to the food that we buy at the grocery store - almost everything around us was weighed using a scale at some point.

    Scales and other measuring devices come in a wide range of accuracy classes. For instance, most deli scales are accurate to only a few grams while a diamond or jewellry scale is typically accurate to a few milligrams (0.003g). For food portion use, a deli scale measures weight accurately enough to make your sandwiches, but if you had to measure something like gold or platinum, you would want to use a jewellry scale.

    Measurement Accuracy

    But how do you know if the scale you are using is accurate? If you check the various clocks around you, you might notice they don’t all agree with each other, with some more accurate than others. Th

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