Electrostatic Units (e. s. u. : (Elect. Eng. Units for electric and magnetic measurements in which the `permittivity' of a vacuum is taken as unity, with no dimensions on the c. g. s. system. (Chambers)
H. J. Porter (Chairman - Technical Committee), Dictionary of Fire Technology, The Institution of Fire Engineers, The Victory Press (Leicester) Ltd. 1979 UK. (Fr Tech - Brit) {81}