Comparing to measurement techniques - accuracy help!

Hi

I have taken measurements with two pieces of equipment and would like to try and see if one could be used to establish whether the other is working correctly. The correlation coefficient was 0.99.

Both have been measured against standard piece of equipment and I have the relationship of each to that and have come up with an equation to approximately estimate one from the value given on the other but I need to take into account the accuracy of each and just wanted to check if what I was doing was correct!

for example, one device is x, the other device is y and x=1.6y. x is accurate to +/- 0.2 and y is accurate to +/- 0.3.

do I work out the minimum and maximum value of y (y=5, therefore minimum is 4.8, max is 5.2) then do the calculation and then produce the accuracy range taking into account the accuracy of x (min x = 1.6*4.8 =7.68 & max x = 1.6*5.2 = 8.32 - therefore range x should be between is 7.38-8.62)?

Any comments or suggestions would be helpful!

I cannot resolve your English (too many confusing pronouns).

For example, when discussing three distinct objects, do not refer to some of them as "one" or "other" because there is no way for readers to understand which objects you're referencing.

My suggestion is to name things, and then refer to specific objects by their names.

Cheers :cool:

I thought i wasn't that clear, that's why I described the situation with x and y. I am just asking when do you account for the accuracy limits in a calculation.

ap12 said:

i wasn't that clear, that's why I described the situation with x and y.

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I appreciated the x and y, but it seemed like you were unclear with those names, too.

x is accurate to +/- 0.2

y is accurate to +/- 0.3

y = 5, therefore minimum is 4.8, max is 5.2

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Did you intend to write x = 5?

I am just asking when do you account for the accuracy limits in a calculation.

Click to expand...

I'm thinking that you may have meant to say "precision" instead of "accuracy".

Regardless, I'm still unclear about your question, so I'll just answer, "When lives depend upon it".

Don't give up! Perhaps, others will post something more useful for you. :cool: