This document is the first part of a series of standards dealing with the determination of oxygen content in metallic powders by reduction methods. It specifies general guidance to these methods and gives some recommendations for the correct interpretation of the results obtained. The test methods are applicable generally to all powders of metals, alloys, carbides and mixtures thereof. The constituents of the powder shall be non-volatile under the conditions of test. The powder shall be free of lubricant or organic binder. However, there exist certain limitations which depend upon the nature of the analysed metal. These limitations are discussed in Clause 4.