[en] Certain modifications of production technology have been introduced with the aim of meeting growing demands to minimize the difference between the actual and the nominal activities of ²²⁶Ra calibration standards. The reliable filling of sources by centrifugation (the so-called wet route) also suitable for the smallest inner diameters has been introduced. The sorption of ²²⁶Ra on a ceramic sorbent has been tested for the production of the smallest standards with nominal contents of 1 and 10 μg. (author). 3 refs