Abstract: Cleanliness of a metallic material to be tested is provided. The method includes the steps of setting n inspection fields in predetermined portions of the metallic material to be tested, scanning each inspection field by ultrasonic flaw detection method for non-metallic inclusions in the metal thereby to determine the maximum non-metallic inclusion diameter aj (j=1,n), and calculating the estimated maximum non-metallic inclusion diameter amax in the metallic material to be tested from the maximum non-metallic inclusion diameter aj (j=1,n) determined for each inspection field, thereby evaluating the cleanliness of metallic materials quickly with high accuracy and high reliability.

Abstract: The method for analyzing a metal for oxygen, using inert gas carrying fusion/infrared absorption analysis, having the steps of: placing a metal analyte in a graphite crucible; heat-melting the metal analyte; extracting a gas from the melt bath; and analyzing the gas to determine the total oxygen content of the metal in the form of a plurality of separated waves, wherein the metal analyte is heated at a temperature rise rate of not more than 20.degree. C./sec in a period from a starting point A of a first wave to a peak point B of the first wave, held at a constant temperature in a period from the peak point B of the first wave to an end point C of the first wave, and, after the completion of the appearance of the first wave, is heated to melt the metal analyte for further analysis.