Elica LIBRA BL/F/83 Prescriptions De Montage Et Mode D'emploi page 76

LOCK function
The "LOCK" function (21) blocks use of the scale to stop it
from being activated when various objects are placed in the
weighing area.
To activate this function, hold "LOCK" (21) pressed until the
scale display turns off;
Do the same to deactivate the function: hold "LOCK" (21)
pressed until the scale display turns back on.
NB = after 30 minutes of the "LOCK" function being active, the
scale turns off and "LOCK" is deactivated.
36