Bathroom scales

[fly258]

Why do they give a different reading when used on a hard or a soft surface?

[Loosehead]

Mostly they are cheap strain guage junk, they give a different reading depending on a variety of factors, eg stand in the back you weigh different to standing on the front. The hard/soft surface should make no difference on quality scales. If you want reliability use balance scales.

[heathfield]

As Loosehead says, the scales can read differently depending on whether you stand to the front or the back. Using them on a soft surface, the scales can be very slightly tilted, producing the same off-centre effect.

[joko]

because a soft spongy surface has some give, and will absorb some of the pressure and weight that you place on the scales.

[Loosehead]

No Joko, that's a common myth, when that sponging bit is taken up by the weight the spongy material will be indistinguishable from a hard surface.

[mibn2cweus]

The scale in question might rely on a solid platform to maintain the relative positioning of internal parts critical to consistent mechanical function of the weighing mechanism.

[anotheoldgit]

I have some high quality digital scales, they even speak to me in different languages. But these also give a different reading if they are on a carpet, I generally stand them on a piece of board.

[curlyfilm"]

hard.........

[fly258]

Thank you all for your answers, but, no one has explained why.
I know that balance scales are more accurate, I know strain gauge scales read differently if the weight is off centre and I know they weigh differently on hard or soft surfaces, but why?

[mibn2cweus]

. . . cweusly

[Loosehead]

There is nothing to exaplain because you do not weigh differently on a soft surface the different reading is because they are inherantly innacurate the reading varies depending on where you stand how you stand how you balance and any number of factors, try it with a heavy dead weight, put it on the scale, draw around the base then try the weight in the same position on any surface. Try weighing yourself on a trampoline, yep you'll still weigh the same!

[mibn2cweus]

With this thread in mind and having at my disposal the use of a very accurate and precise scale, I removed all removables and thus attired proceeded to eat a sundae-on-a-stick (being the arrogant bass t~rd I am) while standing on the scale. Truth be told I weighed the same after licking the last morsel from the stick as I did when I partook of the first bite. Lo and behold after rendering the polished stick to an adjacent bin I actually weighed a gramme less! Have I discovered a new method of weight reduction?