Standardization of the emerging medical positron emitter 89Zr

89Zr is a beta plus and electron capture decaying radionuclide. This paper presents: (1) Absolute standardization by the 4πβ(PC)-γ coincidence method: a new equivalent decay scheme, the mathematical formalism applied to it and the choice of the optimal measurement conditions. (2) Measurements by HPGe gamma-ray spectrometry, to determine the possible impurities, to measure the activity and the relative intensities of the emitted gamma rays. (3) Calibration of the CENTRONIC IG12/20A ionization chamber, by two methods: direct measurement using the absolutely standardized solution and linear least square modelling, as well as their comparison. (4) Comparisons of results of all measurement methods.