The present invention relates to a sand dispenser for a rail vehicle, wherein the sand dispenser comprises a metering device, a delivery device and an uncoupling device. The metering device is designed to pneumatically meter a desired quantity of sand using a metering air flow. The delivery device is designed to pneumatically deliver the quantity of sand to at least one scattering site using a delivery air flow. The uncoupling device is designed to pneumatically uncouple the metering device and the delivery device, wherein the uncoupling device is designed to provide a compensating air flow for compensating a difference between an output air flow of the metering device and an input air flow of the delivery device.