Drum grader is used for calibration of row fruit (cherries, plums, sour cherries etc).
Calibration is performed using a perforated drum which is made of stainless acid-resistant materials approved for use in the food industry. With different size of perforations along the drum length, it is possible to separate fruit of different sizes. After separation of the different sizes, the fruit is discharged through the funnels into the crates placed below the sieve.

The rotation speed of the drum is regulated by the frequency converter.