A wide range of beta emitting nuclides are offered for counting and educational uses. Certification of all BF Series sources includes both contained activity and 2p emission rate. Sources are traceable to NIST with ±2% to ±5% accuracy at the 99% confidence level. Source configurations are surface conductive on all surfaces to enable their use in windowless proportional counters.

Sr-90 sources produced by EZIP are certified as to the contained activity of the Sr-90 only. Sr-90, a beta emitter, is in equilibrium with the Y-90 daughter. Thus, a 37 kBq Sr-90 source also contains 37 kBq of Y-90. When comparing sources in similar geometries (i.e., similar backing, cover and source detector distance) good results should be obtained. Sr-90 has an average beta energy of 196 keV and Y-90 has an average beta energy of 934 keV, thus care must be taken when comparing sources of substantially different geometries since effects such as backscatter and window absorption must be considered.