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What is your companies Interval Calibration on Inspection Equipment

1953chevB

Cast Iron
Joined
Jul 31, 2020
So over the years, 40-50 years the requirements changed and buz words came an gone.

what specification is your quality manual based on and as the title specifies calibration frequency.

My last company was ISO 9001 C certified and when I retire where in Progress of Rev D
which to my under standing was more complicated and stringent.
Now quality engineering was not my function but I would pick up knowledge from the pro's
who would get us ready for the Agency to certify the company. I am forgetting a lot because
I have been out of the loop for several years.

what was the equipment calibration frequency ?

normal equipment was granite surface plates, CMM, Gage Blocks, Height Gages, Dial Indicators, Micrometers and so on
there was two special equipment (gear shop) , (2) CNC Gear Checker, Red Liners ( Rolling with Master Gears)
 

Eric M

Cast Iron
Joined
Nov 21, 2007
Location
Orlando, FL
Many times, calibration intervals are based on usage, rather than a certain time period, especially if the item is not used on a regular basis. Or, if something is used often, your interval could be more frequently than items that are used intermittently. There's really nothing "etched in stone" that states what your calibration interval MUST be, other than your own Quality Manual. At a previous employer, we would have our surface plates, gage blocks, optical comparators, and CMM's done on a yearly basis. Hand-held measuring tools were 6 months, and thread gages were 3 months. Your mileage may vary...
 

1953chevB

Cast Iron
Joined
Jul 31, 2020
Calibration

Thank You For that reply.

The companies I have worked for used a hybrid system, small inspection tools were calibrated by our quality department, and equipment like surface plates, gear and critical inspection equipment by an outside lab.

here a recommendation from Starrett's web site for surface plates:
6) How often should a surface plate be calibrated?
A) This depends on the plate usage and environment. We recommend that a new plate or precision granite accessory receive a full recalibration within one year of purchase. If the plate will see heavy use, it may be advisable to shorten this interval to six months. Monthly inspection for repeat measurement errors using a Repeat-o-Meter, or similar device will show any developing wear spots and only takes a few minutes to perform. After the results of the first recalibration are determined, the calibration interval may be extended or shortened as allowed or required by your internal quality system.
Questions? Please contact us at (800) 959-0517 or [email protected].
 

1953chevB

Cast Iron
Joined
Jul 31, 2020
Calibration

Thank You for the reply
very good information.

how many employees worked at your shop
 
Joined
May 29, 2010
Location
Denmark
I guess it depends on the volume work to,

As you are retired I'm not sure why you are interested. Calibration intervals, like so much else, aren't the same from company to company. It's something any sensible person or persons in a company gives thought to as it depends on what equipment they have, how often it's used and on what plus who their customers are.

Getting it wrong by not giving it enough thought can quickly become very expensive in more ways than one.
 

MattiJ

Titanium
Joined
May 31, 2017
I think both ISO9001 and ISO17025 leave it pretty much to your own consideration. Risk vs. reward.
Critical piece of equipment could require calibration monthly and stable equipment with small monetary risks could go for years.

Entirely different field(Temperature cal lab) but we have calibration intervals from 6 months or before each use to every 10 years.
Sometimes you need to set the calibration interwals based on customer expectations ie. what looks good to customers.
For example water triple point reference is either broken to pieces or it works... stability or drift rate is mostly academic interest(sometimes slowly drifting when borosilicate glass dissolves in the water! and alters the triple point value)
 

tonymor

Aluminum
Joined
Feb 9, 2017
Location
Chambersburg PA USA
I think the main thing with ISO is that you have records of doing the calibrations when you say you are going to do them. The actual interval does not matter. Of course it matters in practice, but it doesn't matter to whoever does the audit, so long as you're doing what you say you're doing.
 
Joined
May 29, 2010
Location
Denmark
I think the main thing with ISO is that you have records of doing the calibrations when you say you are going to do them. The actual interval does not matter. Of course it matters in practice, but it doesn't matter to whoever does the audit, so long as you're doing what you say you're doing.

Exactly. Too many when writing overlook that it becomes a "legal" document and exaggerate because at the tme it looks good. Only later do they realize that it's better to write too little rather than too much. No auditor or customer will complain if you do more than you have written. They certainly will if they catch you doing less.
 

1953chevB

Cast Iron
Joined
Jul 31, 2020
Gorden
Old habits are hard to break.
Yes I am retired but do have a consulting
One man buisness, I mostly help companies with gear design and manufacturing. Aerospace and Aircraft
Loose tough to manufacture gears.
I always being this way about learning
And staying busy.
If I have experience I try to share it.
Where as it may not benefit me it could benefit those starting a new buisness.
In the archives.
 
Joined
May 29, 2010
Location
Denmark
Gorden
Old habits are hard to break.
Yes I am retired but do have a consulting
One man buisness, I mostly help companies with gear design and manufacturing. Aerospace and Aircraft
Loose tough to manufacture gears.
I always being this way about learning
And staying busy.
If I have experience I try to share it.
Where as it may not benefit me it could benefit those starting a new buisness.
In the archives.

I certainly agree that old habits can be hard to break but not impossible :cheers:

I'm sure you're good at what you do but calibration isn't one of those things. To me your OP was more misleading than helpful. I'd strongly advise you not to give any help to a customer on calibration. I can't remember any ISO quality specification that stated specific calibration intervals. What people write in their Quality Manuals is a very different thing. My experience with "quality consultants" isn't good and it becomes more theoretical than practical. I'm sure those that hire you is for your knowledge on gear design and manufacturing.

If you came into a situation at one of your customers and calibration came up then you could present that specific issue here and I'm sure you'd get answers.
 

1953chevB

Cast Iron
Joined
Jul 31, 2020
I certainly agree that old habits can be hard to break but not impossible :cheers:

I'm sure you're good at what you do but calibration isn't one of those things. To me your OP was more misleading than helpful. I'd strongly advise you not to give any help to a customer on calibration. I can't remember any ISO quality specification that stated specific calibration intervals. What people write in their Quality Manuals is a very different thing. My experience with "quality consultants" isn't good and it becomes more theoretical than practical. I'm sure those that hire you is for your knowledge on gear design and manufacturing.

If you came into a situation at one of your customers and calibration came up then you could present that specific issue here and I'm sure you'd get answers.

:codger:
LOL yes I will not, your right stick to what I am good at, but Gordon I did get you to make me a better engineer.
cheers My friend Have beer :D

I had the conception calibration was specified in ISO 9001, I have learned, why because I can.
 

mneuro

Cast Iron
Joined
Sep 15, 2014
Location
Plymouth, MN
Of the shops I have been in the last decade or so, it was a mix of ISO9001 and AS9100. Calibration was the same for all 3 shops.

Hand tools: 1x per year
Thread gages: 1x per year
Gage pins: 1x per year
Gage blocks common: random sample 1x per year
Gage block master: 1x per 3 years
Large equipment in common use (cmm, optical comparator): 1x per year
Large equipment minimal use (hardness tester): 1x per 3 years
Regular use surface plate, checked 1x per year, lapped every other year
Shop surface plates, check 1x per year, lapped every 5 years
 

1953chevB

Cast Iron
Joined
Jul 31, 2020
I've seen people go 10-20 years with no outside calibration paid for and yet be very successful in making the customers happy.
Some basic cal and repeatability checks can be done in house better than going outside.
Bob
I believe your right just depends on the accuracy of the work,
a lot of our work was .0001-.0002 inch tolerance so a lot of equipment had to be top tip condition
 

mneuro

Cast Iron
Joined
Sep 15, 2014
Location
Plymouth, MN
I believe your right just depends on the accuracy of the work,
a lot of our work was .0001-.0002 inch tolerance so a lot of equipment had to be top tip condition

That is a valid point. I have always worked in tight tolerance work. Some of the small shops I have spent time in where the work is mostly ±.005", have never had outside calibrations done. Type of work is probably a huge factor.
 

MattiJ

Titanium
Joined
May 31, 2017
Some aerospace standards seem to be exact opposite of general blabbering in ISO9001/17025: Everything is specified top to bottom in the calibration chain with no flexibility at all. Leading sometimes to weird workarounds. :skep:
 
Joined
May 29, 2010
Location
Denmark
Some aerospace standards seem to be exact opposite of general blabbering in ISO9001/17025: Everything is specified top to bottom in the calibration chain with no flexibility at all. Leading sometimes to weird workarounds. :skep:

Not within aerospace but I've known some Japanese companies insist on tighter tolerances than "standard" when buying. The good news is that they are willing to pay extra for their requirements. Forget their special requirements and you can be sure to get what you sent returned.
 

Pathogen

Hot Rolled
Joined
Oct 18, 2016
For the FDA years ago it was make sure the records were up to date. Never mind the calibration procedure was a joke.

For the Military contracts there were many options.
1.) Get the old guy to sign it off, he will sign anything
2.) Let her do the cal, she doesn't have a clue what she is doing
3.) Reassign the serial number because no one can get it to work and sign it off
4.) Hire the calibration company with the fat guy that comes in and puts new cal stickers on everything so we don't have to go without equipment.
5.) Put stickers on it that say Calibration Not Required
6.) Hide it
7.0 The company that oversees the Calibration is a watchdog for our work, but they are only here on the day shift, so do it tonight and have it ready to ship in the morning.
8.) Change the calibration procedure
9.) It's going on the shelf in a warehouse, what's the problem here
10.) Do in house calibration and buy them fancy labels

You get the drift

Personally, I like calibration. I think it should be right up there with safety.

The stuff I work on now can go several years but we do it way more frequently because we want to upgrade software.
 








 
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