# Purpose of calculating Uncertainty value in calibration study

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#### Prasanna Venkatesh

Can any one please explain in detail what is the purpose of calculating uncertainty value for an instrument as part of calibration study and also what is that value meant ?

#### J0anne

##### Joanne
The uncertainty calculation is a quantitative indication of quality.

If your uncertainty is large, the level of confidence will be low.
95% uncertainty 5% confidence.

If your uncertainly is small, your level of confidence will be high.
5% uncertainty 95% confidence.

#### AndyN

##### Moved On
Can any one please explain in detail what is the purpose of calculating uncertainty value for an instrument as part of calibration study and also what is that value meant ?

If you firstly understand that any process has variation, then you will understand measurement is a process. If you wish to know, when making a measurement, (say of a product characteristic), with some degree of accuracy, you need to know the influences of the actual measurement process, on the process of making that measurement. The equipment used is one of the influences. Understanding that influence allows you to see the "spread" of the influence. As Joanne says, the lower the influence, the higher the degree of accuracy.

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#### Prasanna Venkatesh

Dear all,

Thanks for your prompt response. Can you please clarify by referring below example which i have taken from perfect calibration centre,

External micrometer
Range: 50-75mm
Least count: 0.01mm
Uncertainty of measurements = +/- 0.00243mm
K factor=2
Confidence level=95.45%

Here please explain how uncertainty of measurement is calculated ? If you want i will share the calibration report also. I hope these details are enough

#### AndyN

##### Moved On
Dear all,

Thanks for your prompt response. Can you please clarify by referring below example which i have taken from perfect calibration centre,

External micrometer
Range: 50-75mm
Least count: 0.01mm
Uncertainty of measurements = +/- 0.00243mm
K factor=2
Confidence level=95.45%

Here please explain how uncertainty of measurement is calculated ? If you want i will share the calibration report also. I hope these details are enough

If you click on the green button "Post attachments List" and do a search on "Uncertainty", you'll find what you're looking for.