초고온 열팽창율 및 열팽창계수측정기 (딜라토미터)

UNITHERM™ 1252V

▣ Ultra High Temperature Dilatometer
▣ Single or dual sample
▣ Research quality
▣ Sintering studies
▣ Full range optical pyrometer
▣ Vacuum or inert atmosphere
▣ ASTM

온도범위 : RT~2000/2500/2800°C Temperature range

This instrument is a fully automated dilatometer system designed to measure dimensional changes of a specimen brought about by changes in its thermal environment. Linear thermal expansion coefficient, shrinkage attendant to sintering, phase transformations, annealing characteristics and other physical or chemical changes manifesting themselves in a change of a linear dimension can be precisely determined. Processing parameters can be studied in great detail through duplication of actual thermal cycles and rates. Due to extensive cycle programming, even complex processes can be simulated.
The digital displacement transducer(s), used in the system is an absolute device with no periodic calibration requirements. It is free of short term drift and long term changes, as its accuracy is based on a very stable internal glass grating whose movement is optically monitored.
Temperature control and sample temperature is determined optically. Exclusive full-range pyrometer covers the operating range from ambient to 2800°C. Optionally, the standard graphite dilatometer tube is made to be interchangeable with alumina or silica tubes.

The dilatometer head slides up and down on guide rods to expose the sample holder (see dilatometer tube photo below) from the furnace cavity. For smooth operation, the head-lifting mechanism is counter-balanced with constant force springs. When inserted, sliding hermetic seals close the cavity to provide a protective environment for the specimen. Critical components, such as the seals, the base of the dilatometer head, the solid state power controller, and the step-down power transformer are water cooled.

The vertical configuration of this device makes it especially suitable for testing ceramic or other powder pressed materials where shrinkage often accompanies heating. Pushrod tracking forces are governed by variable dead weight counter-balancing, and can be reduced to very low values. Optionally, loading can also be applied through additional weights.

The Unitherm™ line features automated systems designed to measure the various thermophysical properties of solids. All instruments in this family use the Windows™ platform to interface to a personal computer, which can be provided as a turn-key system.
An extensive tutorial is supplied with each instrument to allow self-teaching of the operation. On-line help screens are available in every phase of the program, greatly minimizing the need of referring back to the manual in case of questions while setting up or running a test.

Temperature Programming and Control
The system offers a user programmable mix of ramps, dwells, soaks, and printing rates, delayed start, repeat-cycle capability with a program capacity of 16 thermal cycles (64 segments), and the ability to store and recall frequently used programs. The temperature program is fully displayed and is editable during a run. All vital test parameters are continuously displayed and updated. Digital temperature control with optimized adaptive routines is used to achieve accurate sample, rather than furnace temperatures. Controlled heating rates up to 30°C/ min and uncontrolled rates up to 100°C/ min can be achieved.

Data Recording
Measured data is displayed in real time and is continuously stored on disk for further analysis. All test and program parameters along with system correction and standards data are also stored in each test data set for easy comparison of tests at a later date.

System Correction and Calibration
Built-in system correction and calibration tables that can be verified or altered if desired are included. System correction can be altered, based on calibration runs with NIST standards or other references.

Data Reduction, Analysis, and Reporting
Stored data is automatically processed by statistical methods, for all points (such as with ramp heating, where applicable). The analysis includes polynomial curve fitting, and tabulation of results (such as percent expansion, average coefficient, and instantaneous coefficient, etc.) as a function of temperature. A variety of single or multiple curves for a group of tests can be generated, displayed, and hard copies produced using the printer.

The extremely user-friendly, fully integrated, proprietary software (developed in C++ specifically for each instrument) is totally transparent to the user and requires no computer programming knowledge. Optionally, data files may be downloaded to other computers for further processing.

Safety and Diagnostic Features
Built-in safety provisions ensure that operational malfunctions will not cause catastrophic failure of the system or destruction of the sample. Loss of water flow, four levels of furnace and sample over-temperature, and dead computer detection are among the functions that are continuously monitored. Some will automatically shut down the equipment while others alert the operator via audio-visual indicators. Diagnostic routines allow the operator to exercise and interrogate the failed system to determine the cause.