Calibrating / verifying scales

[Knut]

Guys,

All this talk of big variations in the weights of components got me thinking. Definately there are some variations due to production related issues, but I believe that there may also be some related to the accuracy (more or less) of our scales.

So, have you / do you regularly verify(ed) that your scales are spot on when weighing new stuff?

If you do, how do you do it?

[Tippster]

I work at a Power Station and have access to out Chemistry Lab scales.

they are accurate to +/- 0.02g and are calibrated every 6 months.

[madcow]

You can buy calibrating weights from most good scale suppliers. A must have if you want accurate readings.

[rockymtnway]

I find I lose some accuracy through rounding as well as some inherent scale inaccuracies. My new Extralight cranks were 496g, the big ring was 61g, middle ring was 32g, and small ring was 15g with four aluminum chainring bolts equalling 15g. The weight when assembled was 622g, 3g more than the sum of the parts.

[Tippster]

I find I lose some accuracy through rounding as well as some inherent scale inaccuracies. My new Extralight cranks were 496g, the big ring was 61g, middle ring was 32g, and small ring was 15g with four aluminum chainring bolts equalling 15g. The weight when assembled was 622g, 3g more than the sum of the parts.

you'd be pretty unlucky to get a 3g rounding error from just 5 parts...

[Knut]

You can buy calibrating weights from most good scale suppliers. A must have if you want accurate readings.

Exactly, and I was just wondering if other weightweenies do that?

[Boonen]

You can buy calibrating weights from most good scale suppliers. A must have if you want accurate readings.

Exactly, and I was just wondering if other weightweenies do that?

I put a 100 gr. weight I borrowed on my scale and it was 100 gr. indeed. The scale also weighs in 1 gr. inclements, so I guess it's acurate enough for weighing bikeparts (for me anyway). But what do you do when the scale is off by a couple of grams? I bet the more expensive scales have ways of correcting this, but my inexpensive scale doesn't have that.

[Knut]

[quote="Boonen]But what do you do when the scale is off by a couple of grams? I bet the more expensive scales have ways of correcting this, but my inexpensive scale doesn't have that.[/quote]

I guess you sell it in the classifieds and buy a new, more accurate one?

Or, you could correct your weights with the known variables?

[jeremyb]

i have a 200 gram verifying weight, but when i measured my new frame the other day between 2 scales they were 22 grams off each other, even though at 200 grams they were both perfect.

Now i want a 2-4 lb accurate weight to confirm heavier item's weight like a frame or wheelset.