The present invention relates to an irradiation device (36) for irradiating packaging containers (12) with electron beams in a filling machine. The irradiation device (36) comprises at least one electron beam emitter (10) and at least one sensor device (56) for measuring at least one dose control parameters of the electron beam. The sensor device (56) is arranged to measure said dose control parameter of the electron beam of said electron beam emitter (10) in between packaging container irradiation cycles. The invention also relates to a method.