Reference block 2(EN ISO 9934-2)

Reference block type 2 is a self contained unit requiring no external magnetic field induction. It comprises 2 steel bars and two permanent magnets. It shall be calibrated such that the +4 mark represents +100 A/m and the -4 mark represents -100 A/m.
Indication lengths give a measure of performance. Indications start at the ends and decrease towards the centre. Increased length show better performance. Results shall be the cumulative length of the left and right hand indications.