our excell scale model SI 132, 1.5kg having problem on external calibration procedure. The 02 EC on weight calibration page was disabled. i was confuse about the note written below on that page. saying," in approved model, CFn 02 set as 1 or 3, then 02 EC was disabled. could you help me to fix this problem to make this 02 EC become enable to calibrate our scale. thanks and best regard..