First Time Managing Calibration and Measurement System. Need Help.

[CaliperJim]

Are there any specifications you must adhere to such MIL-STD-45662A? Will any of your customers use NAV04 to audit you? Those documents provide calibration system requirements that affect what we calibrate in house. Given the accuracy requirements, the NIST traceability requirements, the uncertainty requirements, it's not cost effective for us to calibrate thread plug or ring gauges or gauge blocks.

 

[mattador78]

OK
Worked for me in a few machine shops I've managed Quality in, though
Pins - the cost of replacement wasn't a concern to those companies I worked at. I had limited personnel resources to do full verification and it was simply cheaper and more expedient to buy new every couple of years and send the old out to the floor as "reference only".
Blocks - we sent out for recertification.

They preferred to do that vs buy a highly accurate bench mic or a CMM

We have had a similar experience here with pH meter's and found it easier and cheaper to buy a new one with a cert and pass the old one out to the shop floor where they are used to reference against the master. Worked out costing us £10 a year extra but we have multiple spare pH meters with a new one only used in the lab each year. I suppose as stated it is what works best and is conforming to what the customer wants on an individual basis.

 

[RCasey88]

Thanks everyone for the advice. I do however have a couple more questions. I have a CMM here in the lab. Can I use that to calibrate the blocks, pins, etc? Obviously not calipers and such. Also, Im going to go ahead and assume that the method of using thread wire is the only/prefered way of doing calibrations of thread instruments like plug and ring? I am curious to know if thread plug have ever been calibratied by thread rings and visa versa with only having the "Master" plug/ring fully calibrated using the wire method.

 

[Ron Rompen]

RCasey, you can use ANY method you like to calibrate your instruments - none of the standards that I am familiar with (automotive) say HOW you have to perform calibration, just that you have to perform it.
With that being said, you also need to consider your customers requirements and common sense. For example, you wouldn't want to calibrate your gage blocks with a micrometer, and then calibrate that same micrometer with those gage blocks.......

 

[RCasey88]

RCasey, you can use ANY method you like to calibrate your instruments - none of the standards that I am familiar with (automotive) say HOW you have to perform calibration, just that you have to perform it.
With that being said, you also need to consider your customers requirements and common sense. For example, you wouldn't want to calibrate your gage blocks with a micrometer, and then calibrate that same micrometer with those gage blocks.......

Ron,
Thank you! That makes perfect sense. I have a 10 year background in automotive but i am fresh into the completely different world of aerospace...So still learning of some standards.

 

[Ron Rompen]

Ron,
Thank you! That makes perfect sense. I have a 10 year background in automotive but i am fresh into the completely different world of aerospace...So still learning of some standards.

Aerospace may have some industry-specific requirements with regards to calibration methods and procedures. I know that (in general) they are much 'pickier' about things than automotive is. Be sure to validate your plans and proposed practices. You SQE should be able to guide and assist you in ensuring that what you are proposing will meet with their requirements.

 

[Paul Simpson]

There is a lot of information out there in the public domain. I'd start with looking at applicable standards - ISO provides free information on their online browsing platform - here. As has already been mentioned, the aerospace sector and specific customers may have their own requirements.

 

[RCasey88]

SQE should be able to guide and assist you

He should, you are correct. However, not to bash on him but He is also new to his position and aerospace just like me. So we are both trying to tackle this with little to no knowledge of aerospace industry. So far all of the research I've found points me into the direction of canceled, deleted or non existent documentation or i am presented with superseding documents that don't answer any of my questions.

 

[Jr Flores]

Hi Rcasey
I dont calibrate my pin gages what i have done is that i added in my work instructions that i have to verify the pins after each use with a calibrated equipment in this case with a pair of micrometers. But i do buy starret calibrated pins with dimensions that have tight tol like dia .125 +-.0005. And i do sent those pins for calibration.

 

[RCasey88]

Hi Rcasey
I dont calibrate my pin gages what i have done is that i added in my work instructions that i have to verify the pins after each use with a calibrated equipment in this case with a pair of micrometers. But i do buy starret calibrated pins with dimensions that have tight tol like dia .125 +-.0005. And i do sent those pins for calibration.

Hi Jr,
I appreciate the tip. Do you think it would be too much to "verify" before and after each use only when in use? Or is it better to do beginning of day vs end of day?