What is maximum limit for MU (Measurement Uncertainty) or acceptable criteria?

[mmurat]

Hi, I have been working as Calibration superintendent. I studied and searched MU but I couldn't find my questions about evaluation of MU. How can I show MU and what is max limit of MU or accaptable criteria?

if Anyone can help me ,I will appreciate it.

Thanks in advance.

[Hershal]

Showing MU is typically accomplished using either a simple statement or somtimes a chart if there is a different MU for each reading. MU is also typically expressed as "k=2 to approximate 95% confidence" and the statement needs to be there to explain the expression of M.

Ther is not really a limit to MU, but depending on what you are calibrating, the MU likely won't exceed about 1%.

Hope this helps.

[mmurat]

Thanks Hershal for your help.

[mmurat]

Hershal,

MU for any instrument is written to its certification. This MU should be calculated according to a butget including instrument resolution,temp difference and thermal expansion etc.When I buy a instrument,can ıI use uncertainty indicated on the certification adding repeatability? Or Do I have to calculate MU according to new budget?

Thanks in advance

[Hershal]

Great question!

When you obtain the instrument, the uncertainty stated is what is delivered to you. The uncertainty of your measurement will take that into account and also add any other factors present in your measurement, including the repeatability.

Other factors may also need to be included, for example, temp and humidity, vibration, dust, barometric pressure, or other influences that can affect the measurement.

Thus, the uncertainty of your measurement will be greater than the uncertainty as delivered to you, and depending on what kind of measurement you are doing it may be much greater or only a bit.

Hope this helps.

[mmurat]

thank you for your response and help.