Many marco systems boast a further useful feature: precise volumetric control. The position sensors in the media supply tank mounted either in the piston of the special cap or in the high pressure pump, provide an extremely precise reading of the dispensed volume. The direct correlation between dispensing parameters (cycles, opening time, supply pressure) and dispensed volume means the dispensed volume can be kept at a constant level over a long period even if the media properties change over time. The deviation tothe target volume does not exceed 1%. With media where viscosity increases over time for example, a readjustment of the opening time or of supply pressure will ensure that the volume set at the start of the process remains constant throughout the whole production shift (contents of one cartridge).