Some Recent Developments in Noble Metal Thermocouples 630364
Since the temperature-electromotive-force relationships of thermocouples in general cannot be expressed by a simple equation, it is convenient if not necessary to have empirical tables of temperature versus thermal emf (reference tables). Five such tables are presented. They are for the relatively new thermocouples palladium, versus platinum and 15% iridium (PPI); Platinel II, 40% iridium and 60% rhodium versus iridium; 50% iridium and 50% rhodium versus iridium; and 60% iridium and 40% rhodium versus iridium. Brief descriptions of the experimental apparatus and procedures are included. In the case of Platinel II, work to determine its thermoelectric stability is discussed.