During both charging of refrigerant and during the recovery of refrigerant a weighing platform should be used. During the recovery process refrigerant is put into a refrigerant cylinder. The danger is that these cylinders can quickly be filled past their “safe fill” level”, which is generally considered to be 80% at 21°C. Anything over this does not allow sufficient room for expansion should the temperature rise.
During the charging process a specified amount of refrigerant is removed from the cylinder and added to a system. A weighing platform is used to weigh in the refrigerant and ensure that the system is correctly charged.