calculations of flatness based on EN 485-3
calculations of flatness based on EN 485-3
(OP)
Hi
I have some problems with understanding idea of calculating overall deviation - does anyone of you are familiar with this standard?
a) "%" is not strictly clear for me, what are they reffering to when considering percentage values?
b) why widthwise deviation is percentage larger than longwise deviation? shouldn't this be opposite?
thanks
I have some problems with understanding idea of calculating overall deviation - does anyone of you are familiar with this standard?
a) "%" is not strictly clear for me, what are they reffering to when considering percentage values?
b) why widthwise deviation is percentage larger than longwise deviation? shouldn't this be opposite?
thanks





RE: calculations of flatness based on EN 485-3
RE: calculations of flatness based on EN 485-3
a) Take a look at the attached pdf containing some screenshots from EN 485-3:2003. This should help you to better understand what the table with general flatness tolerances is about (at least in the standard it is clear what the letters "L", "W" and "l" represent):
http://files.engineering.com/getfile.aspx?folder=1...
b) Usually length of the sheet or plate (L) is n times greater than its width (W), so even though the total/overall percentage deviation is greater widthwise than lengthwise, the dmax for length will most likely be greater.
RE: calculations of flatness based on EN 485-3
I can't figure out how they transform deviation scale between mms and percentage
RE: calculations of flatness based on EN 485-3
RE: calculations of flatness based on EN 485-3
Just divide the percentage values from the table by 100 and the problem is gone - 0.3% becomes 0.003; 0.4% becomes 0.004 etc.
RE: calculations of flatness based on EN 485-3