As I said in my provisos mail to fix the problem customer should calibrate load cell.
Usig the manual of the amplifier they should calibrate :
Zero by F3
Laod by F5 and F6 in F5 they put the weight that they want tu use than by F6 for confirm
In F8 they should insert 1,5 as first minimum alarm 1.5kg
In F9 the should insert 2 as second alarm 2kg