Calibration or Verification -> Cm and Cmk, etc.

[TLim_AC]

Hi, everyone

I have some questions about calibration and verification + Cm and Cmk.
Can I group Cm and Cmk as "Verification" or not?

Today, my boss asked me "Can we group Cm, Cmk or Cp, Cpk as the verification"? He mentioned that Cm and Cmk usually do not give any uncertainty.
Even though this measurement is performed over 20-25 times with the higher-level reference (or sometimes the same level), we still cannot group it as calibration.
He believes that is not calibration. Actually he thought that it is just "Measurement".

As I read the Cm and Cmk, it seems like doing measurement to see the accuracy of the tool.

As I understand "Calibration" means to do a measurement of two-unit (A higher-level reference and UUC*) to see the deviation and do the calculation of uncertainty.
* UUC = Unit Under Calibration

While the "Verification" does not provide the uncertainty value. It just checks the measurement value of UUC is okay or not by seeing the deviation of an unknown unit result compared to the result of the reference unit (A higher level or the same level).

Not sure about the "Verification", can we use the reference unit at the same level as the unknown unit or not?

(The result is okay or not, depends on the acceptance criteria or requirement of a user).

However, I am not sure that to do verification, can it be performed only a one-time measurement?
If not, what can I call the one-time measurement? Intermediate check?

Please advise me if I misunderstood.

Thank you for your useful advice.

Best regards

TreeLim

 

[Jim Wynne]

I can't tell what you're trying to accomplish. Cm and Cmk are indices for machine capability and have nothing to do with calibration. Please clarify.

 

[TLim_AC]

I can't tell what you're trying to accomplish. Cm and Cmk are indices for machine capability and have nothing to do with calibration. Please clarify.

Hi, Jim Wynne

Sorry for the confusing explanation. My point is to distinguish the type of measurement.
We got the certificate from the customer. It is stated as "Calibration" and tool measurement is done with Cm and Cmk.

As my boss understands, he said it might be verification or something, not calibration.
He replied and made it clear to the customer, however, the customer said it is calibration.
They requested us to provide Cm and Cmk and issue the certificate as calibration.

That made me to find out more details to make it clear to the customer.
Sorry for the inconvenience to you.

Thanks for your advice, Jim.

 

[Jim Wynne]

Hi, Jim Wynne

Sorry for the confusing explanation. My point is to distinguish the type of measurement.
We got the certificate from the customer. It is stated as "Calibration" and tool measurement is done with Cm and Cmk.

As my boss understands, he said it might be verification or something, not calibration.
He replied and made it clear to the customer, however, the customer said it is calibration.
They requested us to provide Cm and Cmk and issue the certificate as calibration.

That made me to find out more details to make it clear to the customer.
Sorry for the inconvenience to you.

Thanks for your advice, Jim.

I'm still not understanding, I'm afraid. Why would you be getting this from a customer? I think you need to go back to the source (whomever it was who sent this certificate) and ask them about it.