Abstract: A method for removing an oxygen molecule from a carbon-monoxide-containing gas which includes removing water from a platinum catalyst by heat treating the platinum catalyst in a heat treatment vessel until the concentration of water contained in inert gas discharged from the heat treatment vessel after being supplied to the heat treatment vessel and used in the heat treatment is less than 1000 vol ppm; and bringing the carbon-monoxide-containing gas into contact with the platinum catalyst to remove an oxygen molecule from the carbon-monoxide-containing gas. Also disclosed is a step of removing carbon dioxide from gas after removing an oxygen molecule using a carbon dioxide adsorbent, as well as a pressure swing adsorption step of recovering carbon monoxide from gas after removing carbon dioxide by a pressure swing adsorption method, to obtain purified carbon monoxide having a purity of 99.95 vol % or more.

Abstract: A method for calibrating a positional relation between a main spindle and a contact tool sensor attached to a table in a machine tool. The method includes: mounting a reference tool on the main spindle and obtaining measurement position coordinates as respective tool sensor measurement values, the measurement position coordinates being of a distal end of the reference tool in at least two different measurement regions on an upper surface of the contact tool sensor; outputting predetermined difference values based on the respective tool sensor measurement values; determining an abnormality when the difference values are compared with preliminarily set acceptable values and at least one of the difference values are out of the acceptable values; and calibrating a positional relation between the main spindle and the contact tool sensor based on the respective tool sensor measurement values when the abnormality is not determined at the determining of abnormality.