Two distinctive techniques have been developed to deliver a quantifiable dose of cesium to a volume ion source. The first method uses alkali metal dispensers in the form of thin metal wires, and the second method allows cesium to be dispensed repeatedly up to a total inventory of ∼8 g. This paper reports on the testing of these devices on two volume ion sources, and details the effects that cesium has on the extracted negative ion current and the plasma parameters. In addition, comparisons are made between the surface production model for cesium enhancement, and a volume or collisional model.