The machine accurately doses gold and silver grains for the prodcution of bullions and cast bars. The Preci-dos is completely automatic, with dosing cells and grains transfers completely controlled by PLC. It has a number of steps to achieve accurate control on final weight. The grains container in the machine are loaded by gravity into the pre-dosing scale, to approach the final desired weight.
After the pre-dosing step, a second phase starts to reach the final desired weight by adding a controlled quantity of gold or silver wire or powder (depending on customer specification) and the discharge the correct quantity of material into a container.
To maintain accuracy and productivity, the machine is capable of self-learning, based on the continuous use. In particular the machine can statistically anticipate the average drop time of a single grain, to avoid overshoot.
The final weight is done using a precision load cell METTLER or equivalent: