New version of the 9th edition of the SI Brochure: v4.01

[Crparedes]

The knowledge model of the SI Reference Point currently reflects the contents of version 3.02 of the SI Brochure 9th edition.

Version 4.01 of the 9th edition of the SI Brochure (https://doi.org/10.59161/AUEZ1291) was officially published today. It no longer distinguishes non-SI units that are either accepted or not accepted for use on the SI. Now, those are simply called non-SI units, and v4.01 includes some additional ones in the list of Table 8, in a non-extensive fashion:

• are, symbol a, to measure area
• hectare, symbol ha, to measure area
• barn, symbol b, to measure area
• angstrom, symbol Å, to measure length
• gal, symbol Gal, to measure acceleration (previously was only a side note)
• bar, symbol bar, to measure pressure
• nautical mile, with no symbol, to measure length
• knot, with no symbol, to measure speed
• var, symbol var, to measure reactive power (previously was only a side note)

Also, the prefix restriction for the non-SI units of time was removed.

Hence, the SI Reference Point should be updated to reflect those changes.

[Crparedes]

In email conversations with CCU President, Prof. R.J.C. Brown, regarding the non-exhaustiveness of the list and the change of status from non-SI units that are accepted for use with the SI to simply non-SI units, he stated:

(The SI Reference Point) could stick with the list you currently have, match the list in the SI Brochure, list more non-SI units than are in the Brochure, or anywhere in between