What do the ISO Codes Mean?

Over the past number of years, the industry has slowly been changing over from the old standard, using 2 numbers (5 and 15 µm (micron), respectively), to the new standard, using 3 numbers (4, 6, and 14 µm)

Click the links below to see a chart of how to interpret these codes.

Old System - 2 Numbers  (Example:    17/14)          View the old ISO Code Chart

New System - 3 Numbers (Example:    19/17/14)    View the new ISO Code Chart

To compare old to new (roughly), simply drop the first number off the new standard.  (Example, as in above: New - 19/17/14 = Old 17/14.  This conversion is close enough for comparison sake.)