METHODS FOR THE OBSERVATION AND MEASUREMENT OF PROPERTIES OF MATERIALS AT ELEVATED TEMPERATURES

摘要

Methods and apparatus for carrying out various physical observation and measurement tests at high temperatures employ a waveguide (26) providing a cavity (28) that is arranged to enclose the specimen (10) under test, the specimen being heated directly by microwave radiation if of sufficiently "lossy" dielectric value, or indirectly by surrounding it with a bed (48) of lossy dielectric material that is heated by the radiation and in turn heats the specimen. The radiation energy is substantially entirely confined within the cavity so that the temperatures to which the surrounding apparatus are subjected are drastically reduced, correspondingly reducing the thermal stresses on the test apparatus. The waveguide can be made in separable parts, or otherwise arranged to be placed around the specimen, and can therefore readily be retrofitted to existing apparatus.