Quote:
Originally Posted by Padgett
My rule of thumb is to drop the least significant digit of a reading. e.g. if it says 3440.3 lbs then I consider that +/- 1 lb.
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Padgett, I'm surprised at you! That is the classic error of confusing resolution (in this case 0.1 pound) with accuracy (which, as you say is unstated). In the same situation as your example, if the reading shows 3340.3 lbs, then the resolution is still 0.1 pound, but the accuracy is 100 pounds. Do you still interpret that as +/- 1 lb? I hope not.
Remember, resolution is the smallest
change that can be detected (in this case, 0.1 lb), but it tells you nothing about accuracy.
Resolution is useful if you are making small changes, and want to know how much change you have made. For example, if you weigh the trailer and get 3350 pounds, then use up a partial tank of propane, then weigh the trailer again and get 3340 pounds, the
difference in readings (10 pounds) will tell you how much propane you used, even if the two weight readings are wrong by a hundred pounds.
Bill