# eli5 why are fighters (boxing, mma etc.) still weighed with old balance scales rather than digital?

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eli5 why are fighters (boxing, mma etc.) still weighed with old balance scales rather than digital?

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They’re more accurate. “Old balance scales” are just “Scales”.

Digital scales are really just a platform on a spring, with a resistance sensor. Every spring is a little bit different in the way that it compresses and every sensor that measures it is also a little bit different. So they need to be calibrated with a known weight, which itself was likely weighed with a regular analog scale. Over time even that calibration can become uncalibrated as the spring and the sensor wear down.

Those analog scales whoever will always be accurate because all you’re doing is balancing a known weight on one side and the players wait on the other side. That’s why they use them at the doctor’s office as well when you’re taking an accurate weight.

Of course I’m sure that it also is just really good for television. You can’t necessarily see the readout of a digital scale when they stand on it, and it probably doesn’t look as cool.

Because it’s all about putting on a show for the crowd and building hype for the fight. Stepping on a digital scale is anti-climatic. Having a person move the analog weights builds tension.

Balance scales will read the same anywhere in the world. The earth’s gravity varies in different places over a range of more than 0.5% so scales based on springs or electronic force sensors can be off by that amount, unless they’re carefully calibrated at the site they’ll be used. Balance scales would even give the correct reading on the moon or Mars.

From a physics point of view, balance scales are are more accurate way to make a measurement that consistently stays the same because it depends on MASS rather than WEIGHT.

No matter what variation there may be in local gravity (say by being at higher altitude), it gets canceled out because you are comparing the counterweights to your weight. By putting weight on both ends of the lever and comparing them to each other, whatever the gravity variation my be in your location it applies to both sides of the lever and thus cancels out. As long as your MASS times the lever distance matches the other side’s MASS times its lever distance, the balance will be centered no matter what the gravity is like where you are.