Advice on milligram/centigram precision scale

[Jenny Physics]

Any suggestion on a good (but as usual not that expensive) scale that can measure at least to centigram precision?

Searching online (e.g. Amazon) I did find some options but the reviews are usually mixed regarding precision (users will say that scales with milligram precision specs are not that precise).

Would like to know your suggestions.

 

[Vanadium 50]

I think you mean "accurate".

Do you need absolute accuracy or relative accuracy? If a scale says 1.092 for one object and 1.082 for another, which is more important? Is it that the two are 0.010 apart or is that a second scale will give the same result?

 

[Jenny Physics]

I think you mean "accurate".

Do you need absolute accuracy or relative accuracy? If a scale says 1.092 for one object and 1.082 for another, which is more important? Is it that the two are 0.010 apart or is that a second scale will give the same result?

I agree that I care mainly about relative accuracy within a few miligrams.

The example you give both 1.092 or 1.082 would be acceptable (although if the two were 0.001 apart it would be better).

But 1.092 and 2.092 would not be ok.

 

[Andy Resnick]

Any suggestion on a good (but as usual not that expensive) scale that can measure at least to centigram precision?

I don't know of any analytical balance that is only accurate to a centigram- milligram precision seems to be the minimum, and the prices start around $400 (US). A few years ago, I found a gently used Mettler AE163, it's fantastic. Look around Biosurplus, LabX, and eBay.

 

[ohwilleke]

Buying laboratory equipment is like buying home exercise machines. I agree that used equipment is definitely the way to go.

A friend of mine operates a commercial forensic laboratory and they saved 80%-90% over the price of buying instrumentation new by purchasing used equipment (five to ten years old) that was discarded by government labs and labs run by big business high tech companies that feel compelled to pay top dollar in order to always have state of the art instrumentation every time something new or better is developed. My friend's business merely needed instrumentation that was necessary to reach forensic conclusions and not to test the laws of physics to their limits or to send missiles half way around the world with a precision of centimeters. The instruments they bought far exceed their requirements and cost less than buying inferior instruments new. And, scientists in labs that were state of the art as of 5-10 years ago tend to take good care of their prize instruments, so gently used is a good description.

The biggest peril when buying used instruments is damage in shipping, which is unfortunately, all too common and can ruin a precision piece of equipment permanently. Be sure to get insurance on any purchase that you don't deliver yourself.

 

[BvU]

Perhaps a paper letter weight scale ?

1 suspension paperclip
2 piece of paper (with scale)
3 thin wire to hang weight from

 

[Dr. Courtney]

Likely overkill for your purposes, but very nice having one in the lab.