A discussion is presented of the principles of the standards that produce temperature scales. The major problems involved in establishing the gas thermometer as the principal standard are reviewed. Based on an analysis of various data and various economic considerations, it is concluded that the application of a new IPTS (International Practical Temperature Scale) as the basis of domestic thermometry has essential advantages over the application of a concrete gas thermometer. The domestic standard system, reproducing temperature scales, should be based precisely on the new IPTS.