Gage Block Calibration/Measurement Control Question

[ISOexcited]

If internal calibration is performed using block gages, which are calibrated by an outsourced process and traceable to national standard (ISO/IEC 17025); do we then have to follow that outsourced standard to perform in-house calibration? We are not 17025 accredited.

I am specifically looking into ISO 9001:2008 standards. Looking to address a lack of environment control. This is in a plastics manufacturing company, and we perform measurements at regular intervals as parts cool. It can, at times, reach temps around 90*F + which could potentially affect the cooling of parts, therefore producing inaccurate measurements.

Thanks in advance for your input. I'm fairly new to this, and trying to figure out how to write up this finding with sufficient evidence.

 

[AndyN]

Re: Calibration/Measurement Control Question

If internal calibration is performed using block gages, which are calibrated by an outsourced process and traceable to national standard (ISO/IEC 17025); do we then have to follow that outsourced standard to perform in-house calibration? We are not 17025 accredited.

I am specifically looking into ISO 9001:2008 standards. Looking to address a lack of environment control. This is in a plastics manufacturing company, and we perform measurements at regular intervals as parts cool. It can, at times, reach temps around 90*F + which could potentially affect the cooling of parts, therefore producing inaccurate measurements.

Thanks in advance for your input. I'm fairly new to this, and trying to figure out how to write up this finding with sufficient evidence.

Are you considering calibration of your gauge blocks? If you are, do you have the equipment to do that? It's not only temperature you need to maintain (you don't need to "control it") you have to have equipment capable of resolving to 4:1 or (better) 10:1 - which puts you in a range of very specialist equipment including highly accurate comparators.

 

[chasf]

Re: Calibration/Measurement Control Question

If internal calibration is performed using block gages, which are calibrated by an outsourced process and traceable to national standard (ISO/IEC 17025); do we then have to follow that outsourced standard to perform in-house calibration? We are not 17025 accredited.

I am specifically looking into ISO 9001:2008 standards. Looking to address a lack of environment control. This is in a plastics manufacturing company, and we perform measurements at regular intervals as parts cool. It can, at times, reach temps around 90*F + which could potentially affect the cooling of parts, therefore producing inaccurate measurements.

Thanks in advance for your input. I'm fairly new to this, and trying to figure out how to write up this finding with sufficient evidence.

The answer in short is no. The gage blocks are your measurement standards mentioned in 7.6 (a).

 

[ISOexcited]

Re: Calibration/Measurement Control Question

Perhaps if I rephrase:

Gages are calibrated through and outsourced process using a different standard than we are accredited with. These gages are used to calibrate our own measuring equipment in-house.

Are we required by ISO 9001:2008, to internally calibrate our equipment under the same controls that the gages were calibrated with?

I.e. Gages calibrated at 65*F, used to calibrate our equipment at 90*F.

Metal expands when heated. I realize it would be minute, however sometimes we do not have room for even slight variance when it comes to our customer's standards.

 

[Jen Kirley]

Calibration service providers are required to have specific controls in order to help ensure consistency of results. After all, we can only guess who is using the gages they are calibrating: operating rooms, nuclear power plants?

Your facility, however, is different since your calibrations are for your own instruments. If we are to consider the effects of thermal expansion, which would be negligible for most of us, it makes sense to not have a very big difference between the temperatures in which your tools are calibrated and in which they are used.

To what tolerances are you be held?

 

[chasf]

Perhaps you should calibrate under the same conditions that you will measure the product under. If .0002 -.0003 makes or breaks the product conformity it would make sense to do so. What ISO 9001:2008 requires for calibration is very general and it allows you to design your calibration system fit your processes.

 

[Jim Wynne]

If internal calibration is performed using block gages, which are calibrated by an outsourced process and traceable to national standard (ISO/IEC 17025); do we then have to follow that outsourced standard to perform in-house calibration? We are not 17025 accredited.

I am specifically looking into ISO 9001:2008 standards. Looking to address a lack of environment control. This is in a plastics manufacturing company, and we perform measurements at regular intervals as parts cool. It can, at times, reach temps around 90*F + which could potentially affect the cooling of parts, therefore producing inaccurate measurements.

Thanks in advance for your input. I'm fairly new to this, and trying to figure out how to write up this finding with sufficient evidence.

The national standard to be concerned with is not ISO 17025. That's an international standard for laboratories. If you're in the US, the national standards are controlled by NIST, and that's where the traceability comes in. You are not beholden to follow any 17025 requirements, although it might make sense to do so.

You need to determine how temperature and RH affect your measurements and make the necessary adjustments. The evidence you need will come from demonstrating that temperature and RH contribute to measurement error.