With volumetric dosing, dosing is based on the volume of the product. For example, dosing is often based on time or auger revolutions:

• Time: The dosing unit is set, to always dispense for a specific time. Then the dosing unit will dispense (approximately) the same amount of product during this dispensing time.
  
• Auger revolutions: The dosing unit is set, to always dispense a certain number of auger revolutions. The dosing unit will then dispense (approximately) the same amount of product in these set auger revolutions.
  

Volumetric dosing usually gives a little less accurate dispensing. In particular, this also strongly depends on the product that is dosed. Some examples of dosing units based on volumetric dosing:

The RVS-200AV+
The KMD-4AV-3

Advantages of volumetric dosing:

• Relatively cheap system/ low investment
• Large dosing range possible
  

Disadvantages of volumetric dosing:

• Lower Accuracy
• Manual setting and calibration of the dosage
• No control over the process and dosage; visual check by operator