title: Comparison of the NIST and ENEA Air Kerma Standards.
abstract: A comparison was made between the National Institute of Standards and Technology (NIST) and Ente per le Nuove Tecnologie l'Energia e l'Ambiente (ENEA) air kerma standards for medium energy x rays and60Co gamma rays. The comparison took place at ENEA in June 1994. Two different transfer chambers from NIST were used for the comparison. The measurements were made at radiation qualities similar to those used at the Bureau International des Poids et Mesures (BIPM) (generating voltages of 100 kV, 135 kV, 180 kV and 250 kV, respectively) and with60Co gamma radiation. The transfer chamber calibration factors obtained at the NIST and at the ENEA agreed with one another to 0.03 % for60Co gamma radiation and between 0.1 % to 0.8 % for the medium energy x-ray beam codes.
authors.affiliation: Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti, Dipartimento Ambiente, Centro Ricerche Casaccia, ENEA, c.p. 2400, Roma, Italy.
authors.forename: R F
authors.initials: RF
authors.lastname: Laitano
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Lamperti
authors.affiliation: Istituto Nazional di Metrologia delle Radiazioni Ionizzanti, Dipartimento Ambiente, Centro Ricerche Casaccia, ENEA, c.p. 2400, Roma, Italy.
authors.forename: M P
authors.initials: MP
authors.lastname: Toni
keywords: Co-60; air kerma; comparison of standards; gamma-ray standards; transfer chambers; x-ray standards