Method and device for operating a pressure reservoir, in particular for common rail injection systems in automobile engineering

A method and to a device for operating a pressure reservoir, where during a compression phase in a pump chamber, a pump periodically increases the pressure of a fluid located therein, and by means of a discharge valve controlled by differential pressure fluid under high pressure is allowed to be introduced from the pump chamber into the pressure reservoir. During a decompression phase following a compression phase, fluid from a fluid reservoir is introduced into the pump chamber by means of a controllable intake valve. In order to be able also to operate the pressure reservoir without a high pressure measurement directly in the pressure reservoir, the fluid pressure in the pressure reservoir is ascertained by means of a pressure determination in the pump chamber. The pressure determination takes place indirectly, monitoring of the intake valve in the decompression phase.