Ceramic high-temperature proton conductor tubes (BaZr0.9Y0.1O3-x, CaZr0.9In0.1O3-x and Ba3Ca1.18Nb1.82O9-x) were found to be suited for introducing hydrogen into a vacuum system. Leak rates below 10(-8) mbar Vs for the assembly, consisting of an active and an 8YSZ support tube, were achieved. The partial pressure of hydrogen in the vacuum system increased lineally with the electric current J flowing through the proton conductor. The other relevant partial pressures were not affected. Measuring the throughput during operation of the hydrogen source showed that within experimental error the total current is used to transport protons to the cathode (transport number t(H) approximate to 1). The number of moles of H-2 pumped into the system per second is given by J/2F. Thus, the device can be used to precisely introduce high purity Hz under current control, and with a response time of a few seconds only, into the vacuum. Similarly, 8YSZ tubes are suitable fur the pumping of high purity O-2 into a system with a rate given by J/4F moles of O-2/s. Since the amount of H-2 or O-2 introduced is precisely known, the present devices can be used for pressure calibration when the local effective pumping speed is known, or else to measure pumping speeds or conductances when accurate pressure measurements are available.