BMU=CMC for every Calibration? ILAC Policy Clarification

[crendfrey]

Greetings all,
I have a question.
First a little background.
My company is accredited to 17025 current addition, through an accrediting body which is a signatory to the ILAC MRA. This gives us the right to display the ILAC symbol on our accredited paperwork, which we do.
Now-as of 1/19/11 and effective 11/1/11 if I read the ILAC policy correctly, I must state the “estimated uncertainty” for EACH calibration.
The question is many fold.
1) Am I reading this correctly?
2) Can I make this a blanket statement similar to my scope budget?
3) I have had one customer ask for a MU on one scale in five years. Do I really need to do the calculations or can I just say I will provide them on request? (which is what I do now. I also provide MU for our proficiency testing and a few other internal documents for my own reference)
4) Am I making too much of this?
5) What do you think?

PS BMU now = CMC talk about confusing people.

Thanks in advance for your insight.

NOTE: ILAC Mutual Recognition Arrangement (ILAC MRA - often referred to as the ILAC Arrangement)

 

[BradM]

Hello there! Thanks for dropping by.

As to the requirement for stating the uncertainty, I'm not sure about that.

But I would be interested why you would not want to list it. Are you currently calibrating uncertainties for your different measurement processes? And, don't you have a published Best Measurement Uncertainty?

Saying, I would think you would have a collective uncertainty that would be applicable to the measurement process you are using for each measurement you are providing to the customer. That to me, would be sufficient to put on the calibration certificate.

To your point, yes, there are a lot of end users that don't understand uncertainty. Thus, they don't care. However, that is changing. That might be a good opportunity to educate the customer on it. Then, when your customers gets pressured for price issues or whatever by their superiors, they can then defend the value of the work they receive from you, based on the quality of the data you provide.

Not sure if that helps or addresses your issue.

 

[Hershal]

Actually, yes, you are supposed to report uncertainty for every calibration - HOWEVER - ANS/ISO/IEC 17025:2005 in Clause 5.10.4.1.b allows use of an "accepted metrological specification" such as in the US, the 4:1 Test Uncertainty Ratio (TUR).

Also, marketplace reality is that many labs offer multiple levels of certificates, starting from a very basic to full accreditation-compliance.

If you use the 4:1 remember you must have the uncertainty studies to support the statement.

The labs that are successful with reporting for every calibration typically have the information built into the software that they use.

 

[crendfrey]

Thank you gentlemen,

Ok….. I have been hanging my hat on 5.10.3.1 c

c) “where applicable, a statement on the estimated uncertainty of measurement; information on uncertainty is needed in test reports when it is relevant to the validity or application of the test results, when a customer's instruction so requires, or when the uncertainty affects compliance to a specification limit;”

I make reference to the standard’s traceability, methods, state, local, fed requirements 17025 requirements etc.

BMU based on the normal 95% confidence, K2 statement and will supply actual MU on request.

Does not 5.10.4.1 b fall within the above statements?
b) “the uncertainty of measurement and/or a statement of compliance with an identified metrological specification or clauses thereof;”
In order to calculate an accurate MU I need to add 10 more weighments.
My standard accredited calibration report consists on 16 as found weighments.

This is cost prohibitive.

Given the state of the industry, people do not want to pay for something they do not care about.
All they want is a pretty piece of paper to show an auditor. Going prices are on a downward spiral and have been for several years. Customers always are governed by price. Very few understand the need for competent calibration. We do offer many levels of calibration. MU calibration comes with an additional cost. As in my previous post, 1 customer in 5 years does not warrant 10 additional weighments for all.

I have a heck of a time getting customers to even determine the tolerances for their own equipment. I cannot determine how much error they can accept.
It is a monumental task getting them to realize it is for their own protection with impact studies and such. (we calibrate as close to zero every time so we do not care what their tolerance is)

I definitely see the need for an uncertainty every time when calibrating mass.
In fact I require it for my standards.
We are talking scales here. 90% of which do not even require class 1 weights.

Thanks for your time and attenion guys