5
57jeeper
Hello to the group:
We have a metric drawing from a European medical company that has a dimension of 4.3 +/- 0.01 mm for a feature. We are measuring the dimension to .001 resolution on a CMM and rejecting for anything less than the low limit of 4.290 mm.
There is an arguement that we should only report to 2 decimil places because that is what the tolerance is expressed as.
This would mean that we would need .005 mm to trip the reading to the next lower 'significant digit' to show an out of tolerance condition.
That would mean anything within the range of 4.285 to 4.315 would read as acceptable if rounded to 2 decimil places.
My thinking is that this practice would add another 50% tolerance to the dimension which I don't believe is good practice.
My question is, is there a DIN or ISO specification that deals with this subject?
I've already checked ISO 2768-1&2 and 8015 with no success.
Thanks,
Mike
We have a metric drawing from a European medical company that has a dimension of 4.3 +/- 0.01 mm for a feature. We are measuring the dimension to .001 resolution on a CMM and rejecting for anything less than the low limit of 4.290 mm.
There is an arguement that we should only report to 2 decimil places because that is what the tolerance is expressed as.
This would mean that we would need .005 mm to trip the reading to the next lower 'significant digit' to show an out of tolerance condition.
That would mean anything within the range of 4.285 to 4.315 would read as acceptable if rounded to 2 decimil places.
My thinking is that this practice would add another 50% tolerance to the dimension which I don't believe is good practice.
My question is, is there a DIN or ISO specification that deals with this subject?
I've already checked ISO 2768-1&2 and 8015 with no success.
Thanks,
Mike