Again, As mechanic says, "trust but verify" use check weights or at least Sierra Matchkings to set/calibrate the scales (both balance and elec.). As I'm sure everyone knows, electronic devices fail due to temp., battery charge, little green men, tides, sonic booms, wife's cooking as well as anything else you can think of! BE CAREFUL- YOU ARE PLAYING WITH EXPLODING STEEL IF USED INCORRECTLY.-Muddy