Calibration object and system calibration control

[[Ro...]]

We have a requirement to control our calibration frequency so we are proposing to have our calibration objects checked every 24months and to record our "system calibrations" everytime the GOM equipment is used. 

However we are having problems justifying how a measuring volume of 1500mm x 1200mm x 1200mm can be calibrated using a CC20/ MV1400 due to the measuring volume Height being more than the length of the object used to calibrate it. Does anyone know how to justify this to an auditor? 

Thanks in advance 

Ross

[[Je...]]

Hello Mr. Hampson,

the measuring volume is not a cuboid, it is more like a pyramid (when getting closer only the the inner part is used for calibration).

You can easy check this by moving the sensor more far away from surface, the blue field will get larger.

(Additional information: The depth of measuring volume to measure reference points can also be exceeded to 3000mm x 1200mm x 1200mm

but only with newest GOM HW and SW).

Best regards,

Jens Braun

 

[[Ja...]]

Ross , this is a really complex topic and it is easy to get caught in the language of 'calibration'

one of the easier ways to understand if the panel is doing its job is to perform regular Gom acceptance tests .

This checks that the combination of calibration panel and lenses/sensor are performing as per the factory standard - inherantly the scale derived by the calibration procedure is 'verified' by this test.

Whilst of course you can get the calibration objects checked / recertified, it is more important to do regular checks via the acceptance test .  If the panel is remeasured it does not mean that the whole system will work as it did at point of delivery.

you could also go down the route of ' golden master'. - checking that your process on your parts is reproduceable with understood bias to other instruments .My favourite analogy is to think about performing a cmm measurement on a sponge.  Whilst the calibration on the machine and standard tests will tell you something about the accuracy  , it does not adequately derive the accuracy/reproduceability of the specific part and process .

I would strongly recommend you engage with your local distributor if you need to understand more about the acceptance test/ calibration procedures.

I hope this is somewhat helpful!