... knife, gun, and copper, aluminums, zinc (more than 150g), ignoring metal in belt button, shoes. 4. Shock proof to avoid false ... and other electrical interference sources. 9. Mix distance between two Walk-thru: 0.3 meters at low sensitivity, 0.5 meters ... Certificate; ISO 9001:2000 Certificate 3. National standard Function: Walkthrough Metal Detector can easily detect weapons, such as knife and gun, and ...