My regular expressions glossary contains |[\u00B5] to have the micro sign µ recognised. That works fine.

However, any combination of µ and an uppercase S doesn't work:

6 μSv/h 

1μSv/h

|[\u00B5]Sv\b etc.

Is this a bug?

Oh my, it's not 00B5 but 

Unicode Character 'GREEK SMALL LETTER MU' (U+03BC)

I'll try with that...

Al fine with:

|[\u03BC]
|[\u03BC]Sv\b
|[\u03BC]Sv\/h\b
|\d+( |\s)?[\u03BC]Sv\/h\b

As we say in Tilburg: Irst kèke, dan kwèke!

(Look first, then shout.)