I bought 175 g pack of salami which had 162 g of salami as well.

  • abracaDavid@lemmy.world
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    9 months ago

    Huh? Well how do we know that any scale at all is right?

    Pretty sure that every modern scale has a “tare” button that resets the weight and zeroes everything out.

    • TempermentalAnomaly@lemmy.world
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      9 months ago

      Taring isn’t the same as calibration. Every scale should have instructions on its tolerance (± x grams) and a calibration weight. You’ll have to buy the calibration weight separately.

    • afraid_of_zombies@lemmy.world
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      9 months ago

      That is only single point calibration. You want more than that in case the transfer function is non-linear. Ideally at least two for the extremes of range.

      Basically imagine if y does not equal x, say y = x -0.01*x + b. Your tare is going to adjust b such that at x = 0 you get y equals 0. That doesn’t fix x is equal to 900. At 900 you would get 891.

      Generally speaking for weight you have differential or integral non-linearity. You fix both by multiple calibration points. Which leads to the range transition problem but whatever. No excuse anymore with FPGAs.

    • QTpi@sh.itjust.works
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      9 months ago

      Well how do we know that any scale at all is right?

      My lab has weights that get calibrated against a NIST standard annually. We use those weights to perform daily quality control that our scale is accurate (to +/- 0.01g). If the quality control fails then we recalibrate the scale.