The effects of pressure, temperature, and physical state on the ability of a barium getter to sorb carbon monoxide are presented. At pressures in the 10−5‐mm range, a five‐milligram getter is exhausted in about one thousand hours. Temperatures ranging from room temperature to 150°C did not affect greatly the rate of gettering or the capacities of the getters. The observed gettering rates or capacities do not obey any simple law over an extended time.