ST113 Flour Magnetic Metal Tester Durable Food Testing Instruments for Determining Magnetic Metal Content ST113 Flour Magnetic Metal Tester is a dedicated test instrument developed and manufactured in accordance with the national standard GB/T 5509-2008, Inspection of Grain and Oils — Determination of Magnetic Metal Matter in Flour. It applies to quality supervision, flour milling (and various grain powder processing), grain storage & transportation, procurement and trading,