Abstract: The standard comparison for Air Kerma of γ-rays with attendance of seven participants organized by the Metrology and Test station of Northwest Institute of Nuclear Technology in 2012 was introduced. According to existing conditions, each participating laboratory chose the ionization chamber of appropriate range to accomplish the comparison. The experiment data of comparison indicate that the deviations between measurement values and reference values are within the reasonable expectation, the results are considered satisfactory.

Key words: γ-rays, Air Kerma, comparison, E_n