D
dna_leri
I am sure this is a basic question but I do not have a reference standard for measurement to give me the answer.
We have a number of plastic moulded parts with a diameter dimension on the drawing. As part of the validation, our design group measures the diameters using a CMM which gives an average diameter measurement. If this meets the drawing spec, then they approve the part. However is we take a min and max diameter, one or both of these may not meet the specification - obviously because the part is not round. There is no roundness specification on the drawing or the location to measure the diameter is not specified.
Is there a standard way of measuring diameter (average or max/min) specified in a recognised measurement standard? My instinct is that average diameter is wrong, but I need some back-up.
We have a number of plastic moulded parts with a diameter dimension on the drawing. As part of the validation, our design group measures the diameters using a CMM which gives an average diameter measurement. If this meets the drawing spec, then they approve the part. However is we take a min and max diameter, one or both of these may not meet the specification - obviously because the part is not round. There is no roundness specification on the drawing or the location to measure the diameter is not specified.
Is there a standard way of measuring diameter (average or max/min) specified in a recognised measurement standard? My instinct is that average diameter is wrong, but I need some back-up.
Last edited by a moderator: