Bathroom scales accuracy( mechanical v digital)

kuepper

My old 'mechanical' scales can be reset to zero if necessary before weighing so I've always thought them accurate. However they've got embarrassingly scruffy looking so I just bought a 'digital' weightwatchers brand scale from Argos. Much to my surprise/horror there's a 7lb discrepancy between the 2 readings. I was going to dispose of the mechanical one but now not sure, how do I know which I can trust?

Spoonie_Turtle

kuepper said:

My old 'mechanical' scales can be reset to zero if necessary before weighing so I've always thought them accurate. However they've got embarrassingly scruffy looking so I just bought a 'digital' weightwatchers brand scale from Argos. Much to my surprise/horror there's a 7lb discrepancy between the 2 readings. I was going to dispose of the mechanical one but now not sure, how do I know which I can trust?

My advice would be to try them on different surfaces, to see if they read the same or similar anywhere. Our digital scales work best on our very hard floor tiles (virtually concrete) then successively worse the softer or more padded the surface (e.g hard lino vs soft lino).

kuepper

Spoonie_Turtle said:

kuepper said:

My old 'mechanical' scales can be reset to zero if necessary before weighing so I've always thought them accurate. However they've got embarrassingly scruffy looking so I just bought a 'digital' weightwatchers brand scale from Argos. Much to my surprise/horror there's a 7lb discrepancy between the 2 readings. I was going to dispose of the mechanical one but now not sure, how do I know which I can trust?

My advice would be to try them on different surfaces, to see if they read the same or similar anywhere. Our digital scales work best on our very hard floor tiles (virtually concrete) then successively worse the softer or more padded the surface (e.g hard lino vs soft lino).

You're only recommended to use them on flat hard surfaces anyway which I have and I only used them in precisely the same spot, still ~7lb difference (9st 11lbs mechanical v 10st 4lbs digital)

savingfortomorrow

i had a mechanical scale and it was out by a small amount per kg. Unfortunately it added up until it looked like I was 10 kg less-than reality. I recommend using scales in another location - find one in a pharmacy or supermarket and it will tell a lot. 
It might be useful to weigh a known weight like a dumbell. 

Spoonie_Turtle

kuepper said:

Spoonie_Turtle said:

kuepper said:

My old 'mechanical' scales can be reset to zero if necessary before weighing so I've always thought them accurate. However they've got embarrassingly scruffy looking so I just bought a 'digital' weightwatchers brand scale from Argos. Much to my surprise/horror there's a 7lb discrepancy between the 2 readings. I was going to dispose of the mechanical one but now not sure, how do I know which I can trust?

My advice would be to try them on different surfaces, to see if they read the same or similar anywhere. Our digital scales work best on our very hard floor tiles (virtually concrete) then successively worse the softer or more padded the surface (e.g hard lino vs soft lino).

You're only recommended to use them on flat hard surfaces anyway which I have and I only used them in precisely the same spot, still ~7lb difference (9st 11lbs mechanical v 10st 4lbs digital)

Well, true, but there can sometimes be a difference between, say, laminate flooring and hard lino/tiles - but certainly not 7lb! And you can only work with whatever surfaces you have.

savingfortomorrow said:

i had a mechanical scale and it was out by a small amount per kg. Unfortunately it added up until it looked like I was 10 kg less-than reality. I recommend using scales in another location - find one in a pharmacy or supermarket and it will tell a lot. 
It might be useful to weigh a known weight like a dumbell. 

Oh that's a much better idea than anything I had to say!

kuepper

Spoonie_Turtle said:

kuepper said:

Spoonie_Turtle said:

kuepper said:

My old 'mechanical' scales can be reset to zero if necessary before weighing so I've always thought them accurate. However they've got embarrassingly scruffy looking so I just bought a 'digital' weightwatchers brand scale from Argos. Much to my surprise/horror there's a 7lb discrepancy between the 2 readings. I was going to dispose of the mechanical one but now not sure, how do I know which I can trust?

My advice would be to try them on different surfaces, to see if they read the same or similar anywhere. Our digital scales work best on our very hard floor tiles (virtually concrete) then successively worse the softer or more padded the surface (e.g hard lino vs soft lino).

You're only recommended to use them on flat hard surfaces anyway which I have and I only used them in precisely the same spot, still ~7lb difference (9st 11lbs mechanical v 10st 4lbs digital)

Well, true, but there can sometimes be a difference between, say, laminate flooring and hard lino/tiles - but certainly not 7lb! And you can only work with whatever surfaces you have.

savingfortomorrow said:

i had a mechanical scale and it was out by a small amount per kg. Unfortunately it added up until it looked like I was 10 kg less-than reality. I recommend using scales in another location - find one in a pharmacy or supermarket and it will tell a lot. 
It might be useful to weigh a known weight like a dumbell. 

Oh that's a much better idea than anything I had to say!

My floor surfaces are varnished wooden floor boards so very rigid. Known weight is a good idea if I could borrow a heavy one from somewhere, it would have to be heavy to get the mechanical scale moving a reasonable amount, though not sure where I'd get something like that from. Are scales in pharmacies etc checked for accuracy?