posted 18 December 2000 01:11 PM               

An interesting point of view that probably would go over like a lead balloon with an auditor. So I don't recommend that. However, it did evoke a great deal of thought on my part about the whole issue.

The issue is having an effective method to assure that the user of the instrument can not use an out of calibration instrument (past due date). How you do that can take many forms. At my former lab (that factory shut down before I could complete implementation), I connected my recall database to the production control database. When an operator in the factory attempted to perform measurements on an instrument past due calibration, the system would not let them perform the measurement. Having given that manager's comments a great deal of thought, it was my intent to eventually have all measuring instruments logged into the production database. Even portable test equipment used in maintenance. Maintenance or product testing could not be completed on any instrument past due calibration. Once a system like that were fully implemented, it would make calibration stickers obsolete.

Obviously, not every company has such an elaborate system to use. I bring it up to make the point that there are countless methods to fulfill the need to make sure an operator knows not to use past due instruments. I have seen companies color code the epoxy sealant in the handles of torque wrenches. Then there were little cards (about the size of pocket calendars) given to each owner, a supply of them to hand out with each new calibration, large color signs hung all over the factory, and other measures to make sure the operators identified whether their tools were past due or not.

I think you can get pretty creative, and make something that works well for you. You could engrave unique ID's on the tools and keep something posted to assure they can't be used past the due date; You could automate it somehow; you could investigate oil resistant labelling; or many other options.

Jim Triller in his reply above offered another creative method. I don't believe it is implicit anywhere in newer standards that the labelling has to be a 'calibration sticker' on the unit with cal date, due date, ID, etc. That is a convenient standard method that works well for many applications (in those cases, if it ain't broke, don't fix it).

However, there are always the exceptions, and circumstances where creativity has to be applied.

posted 18 December 2000 01:54 PM               

I would just elaborate a little and state that calibration stickers are the default. They stand up the best in an audit.

Whenever you deviate from that (and as in your case as well as others, those legitimate cases do exist), you begin treading on thinner ice. My cautoin is that whatever alternate method you use, you have to convince an auditor that all operators know calibration status of their tools.

I think a few details you must cover (perhaps others I miss) include:

-Auditor can't find any instruments past due date.
-Auditor could ask any operator how they know the calibration status of their tools or gages, and they can answer.
-You can demonstrate an effective system that assures both of the above.
-Auditor finds any tool or gage without a sticker on it. They take that tool or gage to someone other than the normal user (but someone woh could reasonably be expected to have access to it), and ask them how they would know whether or not that tool or gage is within it's calibration interval.

I don't believe you are way off base at all. To be more specific to your question. You do not have to use stickers. You do have to be sure the user has an effective method to absolutely know whether their tools or gages are in or out of tolerance. My recommendation is that doing anything other than stickers should be only when you simply can not use them. If that is definite, it is then quite reasonable to create an alternative method. If it were me, I would even expend a little effort to find oil-resistant labelling before I resorted to other methods. There may well be some of those.

Hopefully the combination of the above replies have covered your question.

posted 18 December 2000 04:50 PM               

The standard does not require the operator to know whether or not the gage is calibrated.
IMO, a unique identifying mark and a record of calibration is all that is required.

posted 18 December 2000 07:09 PM               

We are taking it to a level where all personnel are able (and must) access a data base of gages due for calibration (before production on all shifts) and what to do when a gage at the station is past calibration due date.

If we get notice that an operation has a "past calibration" date we know that the calibration system is not effective and then determine the root cause and implement corrective action.

posted 19 December 2000 01:29 PM               

Correct - it does not specifically require that but I would frown upon a situation where the operator had no idea whether the device they were using was 'legal' to use. Reliance solely upon a recall system is dangerous in my opinion. I admit this is my paradigm - If I ran into a situation where the operator did not know if the device they use is OK or not to use (calibration status) I would expect a much stronger system than just a recall system because of all the failures I've seen in recall systems.

And I have seen auditors require it on the basis of training necessary to do their job. Last summer at Ford operators knowing whether their gages were 'in calibration' was required by the auditors in the QS audit. At a Borg-Warner QS audit a year ago this was also required by the auditors - that's where they had the matrix posted at each bench for IM&TE used there -- operators had to show they knew they have to 'be aware' of the calibration status of any IM&TE they are responsible for using.

The criticality of the measurement is sometimes also important -- I sure wouldn't want someone operating a CMM in a critical machining operation who had no idea what the CMM's calibration status is.

I also admit I've never worked with a company where the operators were not required to know the calibration status of the devices they used.

posted 19 December 2000 02:22 PM               

I brought up an automated method in an earlier posting wherein use of the instrument is prohibited by the lot tracking system in a production environment. In such an automated case (and I am certain any auditor would dig pretty deep to make sure the system is effective), there would be no need for an operator to know calibration status as the lot tracking system would not allow them to use it if it is past due for calibration.

But even in such an automated system, you could say that indirectly, the operators knew the status, because when they try to log the product through a test using that instrument, it will not allow the operator to process the product through due to the past due calibration. There are many more bells and whistles in these systems (automated emails to all appropriate people beginning 30 days prior to calibration due date, overdue notices automatically escalated to higher management for any critical measurement tools, and in some highly automated tools, the tool itself is connected into the network and is shut down when it becomes overdue calibration).

Bottom line regardless of whether you use or do not use stickers is that there MUST be some effective method to guarantee measurements on product are traceable (i.e.: in current calibration). Labelling (stickers) is the stereotype method of doing this, and for the most part should be used.

And when ever labelling is impracticable, there still MUST be an effective method to GUARANTEE that measurements are traceable. You can accomplish that however you want. The debatability of method comes in when you user a weaker method. For example, if you hold regular training for operators regarding assuring they only use currently calibrated instruments, it becomes weak. What you have done is improve probability that measurements will be traceable.... Let's use less formal language.. assure you make 'good' measurements. Putting up a list is a good idea when you can't use labelling. But you have to further prove that people read the list. If I were an auditor, that is the first question I would ask... "how do you know the operators will read and abide by the list?"

You may even need to go so far as putting a place on the list for the operators initials and date. This way you will have evidence that the operator actually looked at the due date for his or her instrument. Automated emails or documented emails with return receipts are another option. I think all of this is one of the reasons why labels are so popular (and I have customers who don't read them even when they are on the instrument).

So even with labels it is sometimes difficult to assure the tool can't be used past the due date.

I have struggled many times over the years with the concept of GUARANTEEing that only currently calibrated instruments are used for measurements. Short of complete automation, you can't fully guarantee the above. What you can do is put together a menu of methods that together will reduce probability as much as possible of using overdue instruments.

Alright.... enough of my babbling for the day.

posted 26 December 2000 07:57 AM              

It was good solution for our problems of tickets

posted 30 January 2001 06:42 PM              

You might want to obtain a copy of the "ANSI/NCSL Z540-1994 Handbook" from NCSL. (http://www.ncslinternational.org/) It contains all the sections from the standard plus "Interpretive Guidance" and many "Examples". Go to Section 8.2.

This is a copyrighted document so I can't paste the info here.

Hope this helps.

posted 02 March 2001 08:37 AM              

Of the 2500+ gages we rarely have any fall off, nd it is simple/easy to read.

P.S. If you keep track of a lot of gages, GageTRAK is a good program by Cybermetrics (www.Cybermetrics.com) and it has packages that also come with label makers, PDAs, and Calibration procedures

posted 22 March 2001 03:35 PM               

Are employee owned gages used to verify that product is approved for further processing?

or,

Are employee owned gages used during a machine/product set-up with the subsequent product taken to a lab where a first artical inspection is performed with gages that are part of the calibration system?

I ask because in my experience the set-up personnel use their own gages to set up a machine to meet print specification although their set-up parts are submitted to a controlled lab that verifies that the set-up is acceptable, parts are within specification, and production may proceed.

Generally, I would say that if a gage is used to approve/verify a product for further processing it needs to be included in the calibration system.

posted 23 March 2001 02:54 PM               

Point well take. I would surely not let an uncalibrated gage be used to verify a dimension during the production process.

In my situation the "uncalibrated" gages would be limited to the initial process set-up and verified with calibrated gages during in-process and final artical inspections.

The problem might be the paradigm of set-up personnel not wanting serial numbers on their personal property, as they may move from shop to shop. This is not to say whether they or right or wrong, just my past experiences.

In my perfect world (hahahaha) all gages in the facility would be calibrated, employee owned gages not allowed, and the company supplying all of the required gages.

This is one of those battles that I decided not to fight, but to work into the current process. It's all in the dynamics and requirements of individual companies.

posted 23 March 2001 02:57 PM               

anyhooo, a good discussion!

posted 19 April 2001 11:10 AM               

One of the historical methods for accomplishing this is through the so-called calibration label. With a label on the instrument stating the calibration status, the operators have historically been given the (reasonable) responsibility for knowing that when they make measurements to products that those are "good" measurements.

I think that criteria is a hold over from the old MIL-STD-45662(A) days. So much has evolved since that time that there are much better methods for assuring this. What has to be proven to an auditor is that measurements are "good." As the calibration sticker is such a time proven "standard" method, when you can show effective utilization of the "calibration sticker" method, it is short, sweet, and hopefully no questions asked.

But since the other method you mentioned is "out-of-the-box", although it is a good method, an auditor may be more likely to question. If for no other reason than because the auditor is not intimately familiar with it.

As factory automation becomes more and more universal, automated methods for assuring calibration is current on test equipment will become more common. And it appears that more auditors are becoming knowledgable about the automated methods.

There may be a parallel here at my work. We wear badges to show we are employees. But little by little, they are installing proximity identification equipment wherein I could have my badge in my pocket with a smart card chip inside, and the proximity identification equipment tells whether I am a legitimate employee or not, and consequently either opens a door for me or locks it to keep me out of unauthorized areas.

posted 20 April 2001 06:10 AM               

A weight used to calibrate a balance cannot and it is pefectly acceptable to have the sticker on the box for it.