We propose a system to directly measure Hp(3) quantity both in calibration conditions at laboratories and at arbitrary conditions at irradiation facilities. A commercial ionisation chamber is inserted in a spherical phantom of PMMA such that the system achieves a relatively constant response in terms of Hp(3) and matches the requirements for a secondary standard for Hp(3) quantity. The Hp(3) ionisation chamber was characterized in a dosimetry calibration laboratory under reference conditions and then, as a proof of concept, it was also tested in a work place field at an interventional cardiology department from a hospital. The design method and the measurement results are presented.