Uncertainty calculation - Estimation for a Mettler Toledo XP 56 balance at 20 grams

[howste]

Re: Uncertainty calculation - Estimation for a Mettler Toledo XP 56 balance at 20 gra

I assume that the M3003 referenced in component 4 is the one published by UKAS. How was the air buoyancy uncertainty calculated?

I'm having difficulty resolving the buoyancy number. M3003 says that "a figure of ± 1 part in 10^6 of the applied mass is typical for common weight materials such as stainless steel." For a 20g weight, here's what I get:

20g x (1000mg/g) / 1,000,000 = 0.020mg

The value in the spreadsheet is 0.002mg. Am I missing something in the calculation?

 

[BradM]

Re: Uncertainty calculation - Estimation for a Mettler Toledo XP 56 balance at 20 gra

I'm having difficulty resolving the buoyancy number. M3003 says that "a figure of ± 1 part in 10^6 of the applied mass is typical for common weight materials such as stainless steel." For a 20g weight, here's what I get:

20g x (1000mg/g) / 1,000,000 = 0.020mg

The value in the spreadsheet is 0.002mg. Am I missing something in the calculation?

No, you're not missing anything. Good catch. I revised it to show .02 milligrams.