The Discovery Horizontal Dilatometer is a fully computerized high precision system designed to measure dimensional changes of a specimen brought about by changes in its thermal environment. Linear
thermal expansion coefficient, annealing characteristics and other physical or chemical changes manifesting themselves in a change of linear dimension can be precisely determined. Studies of processing parameters as reflected by dimensional changes of the material can be studied in great detail through duplication of thermal cycles and rates used in the actual process. Due to the flexible programming of thermal cycles, complex processes can be easily simulated.
DHD Design Features
Furnace
A major advantage of the horizontal configuration of the DHD series is its superior thermal uniformity. A horizontal furnace is not subject to convection parallel with the specimen, and can be made a lot more symmetrical than a vertical one. For long specimens, a horizontal system is a must to ensure reasonable thermal uniformity. The DHD-1000 features an air-cooled shell around a water cooled Ni-Cr wound muffle flange to support testing temperatures from ambient to 1000°C. The plate specimen furnace of the DHD-300 is designed to test polymers and other low thermally conductive materials over the range -150 to 300°C by lacing the flat specimen in direct contact with the heating/cooling surface to minimize thermal lag during controlled-rate heating/cooling. Any two furnaces can be configured on a single platform. Additional furnaces can be easily exchanged by the user.
Specimen Holder
The dual DHD-1000 specimen holders and pushrods are constructed from selected grade fused-quartz with matched construction. Featuring an integral specimen cradle, they are designed for easy removal and exchange. The DHD may be operated either as a two-specimen absolute or a conventional differential dilatometer for the highest sensitivity for very small expansion on low-CTE materials.
