  Future sky surveys in the mm/sub-mm range, like the forthcoming balloon-borne
missions LSPE, OLIMPO, SPIDER etc., will need detectors insensitive to cosmic
rays (CRs) and with a NEP of the order of $10^{-17} \div 10^{-18}\,$W/sqrt(Hz).
The Cold-Electron Bolometers (CEBs) technology is promising, having the
required properties, since the absorber volume is extremely small and the
electron system of the absorber is thermally insulated from the phonon system.
We have developed an experimental setup to test the optical performance and the
CRs insensitivity of CEBs, with the target of integrating them in the OLIMPO
and LSPE focal planes.
