You just need the TF100. XL is good option. You likely want to add the Taylor salt test. And the SpeedStir makes the testing easier too.
8x25 mm is the size you wantjumping on this thread - we misplaced our stir bar for the taylor speedstir we have - what size stir bar should we get - is it 25mm does anyone know? Would it matter if it was slightly less - would it still work?
I have both speedstir and sample sizer. Wouldn't do this without them now.