Calibration cycle

Date 07-01-2011 01:16

Mike

I know of a case where a totally fraudulent QC program was uncovered by Bob Waite, in an ABS audit, because the QC Manager showed that the Jo-Blocks were calibrated every year. Gage Blocks might be calibrated every five or ten years!. When Bob asked to see the invoices and purchase orders, the whole house of cards based on phony paperwork fell apart. Something sounds phony. Ask to see the invoices and bills and cancelled checks!

Joe Kane

By jarcher (**)

Date 07-01-2011 03:38

Interesting. Last QA/QC Department I worked in the standards were calibrated annually, as was every gauge and department instrument, including the Pi tape. By order of the President of the company, every tool in every machinist's box was calibrated monthly. Management, in this particular case, the Engineering Manager, determined what was to be calibrated and when. The QA/QC Manager was then responsible for the implementation.

By Mikeqc1 (****)

Date 07-01-2011 12:01

In our manual its the responsibility of the QAM (Quality assurance Manager) to set the fequency when not governed by code or contract requirments.
We could never cal every machinists tool monthly .

By jarcher (**)

Date 07-02-2011 16:59

We tried and tried to get that part of the QC manual changed, to no avail. If I were writing the QA/QC manual, the responsibility for the calibration of a machinist's instrument would rest squarely on the machinist. He would bring it to the QA Department as frequently as was necessary, in his opinion, to be checked by metrologist against the calibrated standards. But then not all engineers have my deep understanding of metronomy. :twisted:

By Mikeqc1 (****)

Date 07-01-2011 11:57

I keep all purchase orders with the Calibration records, our Gage blocks are calibrated every 3 years to NIST.
My concern (no auditor has ever challenged me on this) is the calibration record from the lab they always ask to have everthing back in 1 year.
so if my fequency is 3 years but the lab wanted them in one year .....is the NIST treaceability still valid?
my records and proceedures and cal stickers say 3 years (for the master gage blocks).
One auditor did recomend that i use a new cal sticker to reflect our proceedures (at that time we left the labs sticker only, now i add my cal sticker with the documented cycle).
i think the safest thing to do(being an auditor my self)is have the lab reflect our rotation on the record they provide.
its not phony i keep close account of every tool in the shop and documented as such 500 plus tools.
We go thru 1 to 3audits per year from all types of organizations/customers.
We even got our N stamp with this system.........but you aLL KNOW IN QC IF YOU HAVE A FEELING ABOUT SOMTHING ....INVESTIGATE.

By jwright650 (*****)

Date 07-01-2011 12:39

I have a question regarding test equipment.....if the piece of calibration equipment is a non-wear type and is only used to verify the working inspection tools....why even send it out year after year for calibration...ie IIW cal block. Seems like you could use a statement in your QC manual that you will use the mfg's certification of conformance until there is some damage or some reason that you think the item is suspect.

By Mikeqc1 (****)

Date 07-01-2011 13:29

The manual has the fequency at 3 years, the procedure has a damage clause in it for recalibration beyond the set rotation.
Im not so sure id like that if i were doing an audit on calibration and Looked at the Master Block set (manufactured in say 1972) and never again sent out (2011).
I recomend that they send them out and place them on a rotation determined by the person who is responsible to make that determination.
i think the only change ill seek is on the Record from the Lab id like them to reflect my rotation (no gaps or questionable document flow).

By js55

Date 07-01-2011 12:41

The lab does not determine your calibration/verification rate regardless of what their cert says. Your program based upon governing body requirements determines that rate. The lab will naturally want you to calibrate as often as possible, and they have no idea of the requirements with which you must comply.
Your suggestion to have the lab reflect your program is a good one, though there may be some A2LA, NVLAP, etc., rules they are complying with. I don't know.
But another interesting thing, take look at how long you actually have to keep calibration records. I'm guessing you'll be shocked at what you find (hint: in nuclear you are not required to keep calibration records beyond the last calibration event). I'm not talking industry practice. I'm talking actual governing body, code and standard, programmatical requirements.
Another consideration. Many will argue that you keep records for your own protection. In and of itself this is sound advice. But you also keep records beyond their required term at your peril. Audit world is filled with 'calibration' gurus who feel some things are absolutely necessary that you may never even have considered. I've been beat up by more than a couple of these self appointed calibration gods.
The more stuff you have available for them to look at the more opportunities for them to justify their existence.
Just something to consider before you establish a record keeping system that by default says you'll keep records until the sun burns out.

By Mikeqc1 (****)

Date 07-01-2011 13:54

Auditors always tells me you only need to keep the current and last calibration data.....our records go way way back, its actually more work to purge them than it is to keep them. Auditors including myself are most defiantly preoccupied with calibrations (not saying im of the Auditor GOD mind set), im one of those we work together to smooth out the bumps Auditor.
when getting audited I only show what is asked for. Like you said if you flood them with records the more apt they are to find an error.
A CMM arm with a calibration BAR has a cert the says one year......do you think that calibration bar really needs to go out every year.
Ill need to really look at the paperwork…maybe there are 2 certs one for the unit and one for the BAR.
I don’t want this BAR to go out every year it gets used for one thing only calibration of the CMM.

MDK

By js55

Date 07-01-2011 14:30

Mike,
The great majority of auditors I have been involved with are good guys, conscientious and competent. Some extremely so. You share beers and war stories with them. And yes, the good ones work with you, and often even offer great advice based upon their experience. But there are a few that really make you wanna forget your fork truck safety training (I didn't say that).
I had one that kept busting me on the same thing year in and year out and would never explain why. Just tell me what I was doing was inadequate. When I pressed for the reason or basis he would fall back upon the "I'm not a consultant" ploy and would tell me to read the specification. After 3 years I could recite the specification in my sleep and quote him verse as to how I was in compliance. Didn't matter.
Perhaps we had a personality conflict.

By ssbn727 (*****)

Date 07-01-2011 16:07 Edited 07-01-2011 16:16

Hi Mike,
With respect to some CMM's, if they have a type of granite such as a "black gabro" as opposed to a "pink or blue Vermont/New Hampshire' type of granite in them that practically doesn't wear at all during the yearly time frame with a fairly good amount of use or not, then the yearly calibration would be necessary according to NIST... The Black gabro would more than likely fall out of tolerance with a fairly good amount of use, inadequate preventive maintenance, and care and would most likely have to be re-cut in order to meet the appropriate grade working surface - overall flatness calibration tolerance ...

Of course, it would also depend on the grade of the granite such as whether or not it is a tool, inspection or lab grade with respect to meeting the
working surface - overall flatness tolerances required in order to be either re-calibrated or reworked such as to meet the listed calibration standard tolerances which is usually to NIST and/or similar standards listed on the calibration sticker or plate.

Respectfully,
Henry

By Mikeqc1 (****)

Date 07-01-2011 17:39

Its a portable arm type ...no table.

By ssbn727 (*****)

Date 07-02-2011 05:13 Edited 07-02-2011 05:25

Okay, then do you guys use a "Romer" or a "Faro" PCMM with a seven axis articulated arm measurement system that has the option of using either a tactile probe or a laser scanner or both? Or are you using something like an NDI portable CMM or a "HandyProbe" type CMM (Coordinate Measurement Machine for those of you who want to know what CMM means) that has a lightweight optical tracker as well as a handheld touch probe combined into one very portable hand held machine without any articulated arms? Or are you using a laser tracker with articulated arms for large scale objects in order to preform 3D scans in real time?

In other words what type of PCMM are you using?

Respectfully,
Henry