Forgive me for continuing this theme. I still don't quite get it. Perhaps I am not being clear about the question. Just to clarify:
I am not seeking a definition of SI. I am not seeking to know the history of the SI or any metric system. I am only interested in current status. I am aware that some non-SI units are accepted for use with the SI. We all appear to agree that all SI units are units of the modern metric system. We do not all appear to agree that all units of the modern metric system are SI. That is what I am trying to examine. I am under the impression that the CGPM regards 'SI' as equivalent to 'metric'. This is because they use the following phrase: "... the International System of Units (SI), which is the modern form of the metric system;" It does not say: "... the International System of Units (SI), which is the modern *subset* of the metric system;" If a unit is in the 'modern form of the metric system' it is therefore 'SI' and vica versa. A unit that is 'non-SI' must also be not in the 'modern form of the metric system'. A minute is non-SI and is therefore not metric. My problem is that I was surprised when I read that some non-SI units are described as metric. I can't see anywhere in the text of the SI brochure that supports this. http://www.bipm.fr/pdf/si-brochure.pdf -- Terry Simpson Human Factors Consultant [EMAIL PROTECTED] www.connected-systems.com Phone: +44 7850 511794
