Calibration vs. Verification - Definition of

[Marc]

NOTE: This was posted by Jason on the 'old' forum:

Hello All,

My company has a set of standards (ranging from 1" - 24") that we sent out to be calibrated by a certified QS company. This set is considered the "Master A" set which is the calibrated set. We also have another set consisting of the same standards, but we consider this set to be the "Working B" set and this set is not calibrated. We have 4 pairs of tubular "C" outside diameter micrometers ranging from 12" - 24". My question is: What is the appropriate method or procedure to verify our micrometers are accurate using both sets?

We want to set up our system so that our operators will "work" with the "B" set & then every 6 months to a year, check the mics agains the "calibrated A" set. Could this work for us & how would you record all of our actions.

Thanks...

[Note: This message was edited by Marc Smith]

[Marc]

Jason,

Dick responded to your original posting (which I reposted here) on the 'old' forum. I know you saw Dick's response, but for others it was/is as follows:

-------snippo------

Posted by Dick Lyons on Sunday, 28 June 1998, at 8:38 a.m., in response to Calibration & Verification, posted by Jason on Friday, 26 June 1998, at 6:04 p.m.

Calibrate your "Working B" set by comparing them to you calibrated "Master A" set. Now you can be confident that the operators have accurate standards to work with. This also allows the operators to double check their mics and other equipment against a known measurement anytime between calibration intervals.

Note from Marc: These 'comparisons' have to be documented in your Calibration System...

There are several software programs available that will provide you with the ability to record your calibration data as well as guide you in developing a good calibration system. Try downloading a GAGEtrac demo from from CyberMetrics Corp. at http://www.visit.com

Note from Marc: This url may be (pretty sure it is) incorrect. Hey Dick - What Say You????

to get an idea of what is out there. There are other packages but I just happened to have that one in front of me. Good Luck.

---------snippo--------

Now - Your last post on the 'old' forum:

I guess this message is for Dick Lyons who replied to a recent inquiry that I had... Dick, thanks for the reply. If there is anyone else out there with some knowledge of my needs, please feel free to reply to.

Dick, you suggested that I should look at CyberMetrics at www.visit.com, so I could download Gagetrac. I tried opening up this site, but I cannot get to it. Is this the correct address? It would be great if I could download something that is inexpensive to keep track of my company's calibration & verification procedures.

For those reading this message for the first time, I'll restate my inquiry. My company has 2 sets of standards that range from 1" - 24". One set is considered the "Master A" set which is the calibrated set. The other set is the "Working B" set which is not calibrated. We want our operators to use the "work" mainly with the "working B" set & periodically (6 months to a year) veryify their mics against the "Master A" set. I am looking for some formal inexpensive way to record our data and to meet QS requirements. Our data system doesn't necessarily have to be some high price computer software system either....but, of course, I'm sure that is more preferred.

If someone had a form that they use to keep track & control their calibration &/or verification procedures for their measuring instruments, it would be great if you could attach an example to my e-mail address:

my_con@email.msn.com

Marc Note: E-mail me a copy and I'll post it for everyone!

---------snippo-------

Now - This is in response to your Sunday posting on the 'old' forum.

You can make a form in a FilemakerPro, Access (if you support Bill G.) or another other database (FoxPro comes to mind) for ease, or just make a form in excel or other software. I've seen small companies actually comply with a paper system (but I don't recommend paper systems). The form needs the basics (like equipment type, serial number, etc.), but the main items are: reference point(s) being checked, 'before' reading(s) and 'after' readings.

You would be best off purchasing calibration software which addresses all the issues. The tradeoff between time maintaining a 'borderline' compliance system and just purchasing the software is - well, buy the software... You'll save in the short run, not to mention the long run... You won't regret it!

More and more registrars in QS are requiring proof of competancy in MSA so be careful. Someone in your company really (no kidding) has to understand MSA as a whole (the David Letterman Sky-Cam view) and be able and ready to explain how you 'comply'.
[Note: This message was edited by Marc Smith]

Try a search for CyberMetrics. I did this morning and was successful. There were several CyberMetrics listed but I selected CyberMetrics Corp. and went right to their page. If that doesn't work for you, give them a call at 1-800-777-7020 and have them send a demo disc.

Hope one of the above gets you the info your looking for.

Does this work? Hey Marc & Company....this new forum is kind cool & quite different from you previous forum. Is the other forum still accessible & if so, how much longer? When I post a message here, will I get my replies directed to my personal e-mail address, like the other forum did?

Well, for now, that's all I'll ask. I'll come back with my QS questions later.

[Marc]

The old forum remains up. I plan to leave it there as an info resource but *not* for any new posts.

I'm not sure about all of the software features yet. I know if you initiate a thread you have an e-mail option. I haven't seen where people responding have that same option. There are pros and cons to this software like all other software.

Jason, Microsoft Access is an excellent program to set up your data base. When you look at the sample software consider how many gages you need to conduct your verification on. Many of these software packages may have a lot more whistles and buzzers than you need. However, if you are not familiar with gage R&R protocol, you may want to have that included in the package. Many companies have talented personnel that write and design data bases, you may be able to complete your program by utilizing internal programers.

[Marc]

Use caution if you use microsoft's Access - it is not Y2K compliant. I forget whether they hacked a temporary pivot date fix or library lookup. But - testing has shown it is flakey (as is most microsoft software).

[Marc]

A 'stolen' Thread:

From: nicolet.com (Doug Pfrang)
Subject: FYI: Calibration/Pfrang

1. As I said before, you do not necessarily need to CALIBRATE a tool unless you first determine that there are no other cheaper alternatives for VALIDATING that tool in your process. Therefore, to all of the ISO consultants out there who have tried to advise people on whether or not to calibrate a tool: you should never suggest that any tool be calibrated until you first determine whether or not that particular company has any other cheaper alternatives for validating that tool (e.g., brute force trial and error). Virtually none of the ISO consultants who have posted to this list appear to do this; instead, they appear to use some other surrogate (and incorrect) criteria for determining whether or not to calibrate a tool. Often, the suggestion is to calibrate the tool simply because the person making the suggestion can't think of any other way to validate the tool (i.e., because they haven't explored this option with the client), and they know that calibration will be easy to sell to the ISO auditor. While this is certainly the easiest advice to give from their point of view (since it is virtually guaranteed to work, and thus make them look good), it is not necessarily the most cost-effective solution for the client.

2. Keep in mind that validating a tool by calibration does not mean the tool is any more reliable than if it is validated by brute force. In either case, the tool can drift out of accuracy between the time you validate it and the time you use it. Therefore, the time interval that you choose between revalidations is NOT a function of your METHOD of validation, and it is NOT a function of the calibration cycle recommended by the manufacturer of the tool; it is SOLELY a function of how stable that particular tool is in YOUR particular process. In other words, you do not automatically have to revalidate a tool annually just because that is what the manufacturer recommends. You may freely adjust the revalidation cycle longer or shorter based on YOUR OWN experience with that tool. If the manufacturer recommends that you recalibrate a tool annually, but you find it perfectly adequate -- in YOUR process -- to revalidate that tool every decade, then you are perfectly justified in revalidating that tool every decade. Similarly, if the manufacturer recommends that you recalibrate a tool annually, but you find it unacceptable -- in YOUR process -- to wait more than six months, then you must shorten the revalidation cycle to six months. YOUR experience with the tool, not the manufacturer's recommendations, governs the length of the revalidation cycle. Thus, if you have a tool (for example, a tape measure) and your experience shows that -- in YOUR process -- you can go ten years before revalidating that tool, then that duration is perfectly acceptable as long as you have some reasonable basis for setting the revalidation cycle at that length. How do you show you have a reasonable basis? Just keep a record declaring that you have used this type of tool for ten years and -- in YOUR experience -- these tools haven't gone out of spec in that time frame, so YOU are going to set the cycle at ten years for YOUR process.

3. Many people have posted statements to the effect that "the reason we don't need to calibrate this tool is because we don't need to make accurate measurements with it." This analysis is also wrong. The ACCURACY you need for your measurement is IRRELEVANT to the question of whether or not you should CALIBRATE a tool. The ACCURACY you need for your measurement is only relevent to your SELECTION of which tool to use: the tool you select must be capable of the accuracy you require. Once you SELECT a tool that is capable of the accuracy you require, whether or not you choose to CALIBRATE that tool does NOT depend on the accuracy you require; the decision to calibrate it depends SOLELY upon your assessment of whether or not calibration is the best way to VALIDATE that tool for your particular process. Therefore, to say that "I don't need to CALIBRATE this tool because I don't need to make accurate measurements with it" is wrong. The fact that you don't need to make accurate measurements guides your SELECTION of which tool to use, but your decision not to CALIBRATE that tool is based on the fact that you can VALIDATE that tool easily by brute force trial and error. You try the tool in your process and it works for you; therefore, you have VALIDATED it without having to CALIBRATE it, and THAT is the reason you do not have to calibrate it. But then they make the mistake that most people do -- the mistake which leads to most ISO nonconformities related to calibration -- they neglect to document their validation, which is discussed below.

4. The root cause of almost every ISO nonconformity related to calibration is NOT that the company has failed to CALIBRATE a particular tool; the root cause of the nonconformity is that the company has failed to provide an appropriate QUALITY RECORD showing that a tool has been VALIDATED for the given process. ISO auditors do not looking for calibration records per se; they look for QUALITY RECORDS showing that tools have been VALIDATED for the processes in which they are used. The reason that companies often (wrongly) interpret such nonconformances as requiring the tool to be calibrated is that calibration provides a handy QUALITY RECORD for the company's files, which resolves the nonconformity because it provides adequate evidence of VALIDATION of the tool. However, in virtually every instance, the company could also resolve the nonconformity without calibrating the tool, if it would simply VALIDATE the tool using some other appropriate method and produce a QUALITY RECORD showing that the tool has been VALIDATED and the method by which validation was done.

-- Doug Pfrang