Calibration of Steel Rules

If you have steel rules in use and they are used for measuring critical quality parameters then (as crazy as it first sounds) I agree they should be controlled and calibrated at a suitable frequency.

My idea for doing this would be:

- assess where used in the process, for what measurements and by whom to minimise the number
- only company issued steel rules allowed / documented register held
- calibration would include a check for damage, deterioration and measuring accuracy against a traceable standard

Can anyone with experience add to the above especially on frequency, calibration procedure, tools, how to mark steel rules etc.

Thanks,
Simon

If you have steel rules in use and they are used for measuring critical quality parameters then (as crazy as it first sounds) I agree they should be controlled and calibrated at a suitable frequency.

My idea for doing this would be:

- assess where used in the process, for what measurements and by whom to minimise the number
- only company issued steel rules allowed / documented register held
- calibration would include a check for damage, deterioration and measuring accuracy against a traceable standard

Can anyone with experience add to the above especially on frequency, calibration procedure, tools, how to mark steel rules etc.

Thanks,
Simon

Hi Simon,

Well, Okido apparently knew all about rulers in 2008.

http://www.ifsqn.com...dpost__p__20139

pm/email perhaps ?

Rgds / Charles.C

If you have steel rules in use and they are used for measuring critical quality parameters then (as crazy as it first sounds) I agree they should be controlled and calibrated at a suitable frequency.

My idea for doing this would be:

- assess where used in the process, for what measurements and by whom to minimise the number
- only company issued steel rules allowed / documented register held
- calibration would include a check for damage, deterioration and measuring accuracy against a traceable standard

Can anyone with experience add to the above especially on frequency, calibration procedure, tools, how to mark steel rules etc.

Thanks,
Simon

What you describe was the basic procedure I used in non-food industry jobs in the past. In wood working we had a standard that was available for daily review of tape measures because they were heavily used (and easy to break). The standard was then compared to an outside standard (through a service) every 6 months. In plastics, I did all the calibrations in the lab to a set of blocks but that was micrometers and calipers.

Frequency depends on the critical nature of the tool. I did monthly calibrations (and actually broke them out week by week because of the volume of tools, each operator had their own set) for tools in plastic bottles because one wrong measure could mess up a lot of product. In wood working the only impact was in final fit and you could always "squeeze" the wood together if needed!

Procedure would be to determine the frequency and a method of checking against a verifiable standard. Tools could range from calbration blocks to lasers depending on your need and budget.

If you have steel rules in use and they are used for measuring critical quality parameters then (as crazy as it first sounds) I agree they should be controlled and calibrated at a suitable frequency.

My idea for doing this would be:

- assess where used in the process, for what measurements and by whom to minimise the number
- only company issued steel rules allowed / documented register held
- calibration would include a check for damage, deterioration and measuring accuracy against a traceable standard

Can anyone with experience add to the above especially on frequency, calibration procedure, tools, how to mark steel rules etc.

Thanks,
Simon

I don't have any experience with calibration of steel rules, but I think under ISO 22000 you are required to "verify" if they are capable of the measurement they are being used for. I don't htink your steel rule is always perfect, and therefore, no adjustments needed.

As far as marking/identifying steel rules - in a non BRC environment we use calibration stickers which I think could be liable to come off, so at our BRC accredited site we have stamped each rule with a number.

I would suggest that you

1. buy a new steel rule with a certificate of accuracy or calibration and keep it as a master rule in a protected place.

2. use the master rule to check against all the other master rules and set a standard eg max deviation 0.5mm (it will depend on the accuracy required for your measurements.

3. maintain a register of the checks - each rule will need an identification number

4. check the rules annually

5. I would not expect that a steel rule will go out of calibration unless it is damaged or used in a rough manner.

Mark

Sorry for the late reply, I have noted all replies and have enough to make a simple calibration procedure.

Regards,
Simon