Abstract: Low temperature dilatometers are described which employ a combination cryostat/furnace made from an elongated block of metal by drilling separate longitudinal tubular chambers for insertion of a specimen tube containing a specimen and at least one electric resistance heater. A separate longitudinally drilled tubular cooling chamber serves as the expansion chamber for a conventional compressed gas refrigeration system, one end of the cooling chamber communicating with the inlet of the refrigerant gas compressor and the other end communicating, through an intermediate heat exchanger, with the outlet of the compressor. The metal construction of the cryostat/furnace and the absence of a conventional ceramic protection tube for the specimen facilitates rapid heat transfer to and from the specimen. The specimen can be brought quickly to the minimum desired temperature by operating the refrigeration system until that temperature is reached and then shutting off the compressor.

Abstract: Deformation dilatometers are described for heating, deforming and cooling a test specimen, as well as for measuring changes in the linear dimensions of that specimen. A ferrous metal specimen, that is held between a fixed and a movable fused silica or quartz platen, first is heated by a high frequency induction coil and then crushed by the application of a hydraulic force to the movable platen. The hydraulic force then is withdrawn and, as the specimen is cooled by a jet of quenching gas, changes in its linear dimension are measured by a linear variable differential transformer which is coupled through ceramic pushrods to the platens. Use of fused silica or quartz platens in deformation dilatometers permits the accurate simulation of steel mill forging and rolling operations and enhances the usefulness of the instruments for studying phase changes in steel and determining optimum heating and quenching rates.

Abstract: Low temperature dilatometers are described which employ a combination cryostat/furnace made from an elongated block of metal by drilling separate longitudinal tubular chambers for insertion of a specimen tube containing a specimen and at least one electric resistance heater. A separate longitudinally drilled tubular cooling chamber serves as the expansion chamber for a conventional compressed gas refrigeration system, one end of the cooling chamber communicating with the inlet of the refrigerant gas compressor and the other end communicating, through an intermediate heat exchanger, with the outlet of the compressor. The metal construction of the cryostat/furnace and the absence of a conventional ceramic protection tube for the specimen facilitates rapid heat transfer to and from the specimen. The specimen can be brought quickly to the minimum desired temperature by operating the refrigeration system until that temperature is reached and then shutting off the compressor.

Abstract: Differential dilatometers are described which employ a linear variable differential transformer dilation sensor in which the core and/or coil is independently supported to accommodate the imposition of a constant load on a specimen abutting a pushrod coupled to that transformer element. The independent support system has at least one collar that slidably enages a mating extension of the supported transformer element, thereby permitting long range axial movement of that element while rigidly restricting lateral movement. The collar which thus holds the supported transformer element may be tilted by an adjustable clamp on at least one plant parallel to the path of axial movement of that element, thereby facilitating alignment adjustment.

Abstract: An improved electric tube furnace is described in which a compressible leaf-spring attachment between the heating element tube and at least one of its supporting electric terminals compensates for linear thermal expansion of the tube without restricting access to the interior of the tube. The use of such furnace in an evacuated atmosphere for high temperature thermal diffusivity measurements is shown.