We've report nodules count by comparison with ASTM A247 charts since
many years. Typical values with ASTM A536 Ductile Iron was from 100 to
Now we are looking to use an image analysis software that generates
many data. One of those is nodules count. We had a big surprise that
for our same samples, the software is reporting from 400 to 500 /mm2
and we are interpreting with the charts only 100 to 200 /mm2.
My first try was to eliminate more small particles with the soft. The
results was now less then 400 /mm2 but very far from what we are
expecting. What I think I understand is that those ASTM charts use
samples that have almost one size of nodules. In real life, there are
no samples that can show this type of results. We always have a mixed
population of nodules sizes and shapes. When we try to choose the
right nodules count with the chart we must filter a lot what we see.
Software doesn't do that. It computes what it sees and it's better
Am I the only one who has problems with this?
18 years ago