UNITHERM ™ 1054
DILATOMETER

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These instruments are fully computerized dilatometer systems designed to measure dimensional changes of a specimen brought about by changes in its thermal environment. Linear thermal expansion coefficient, shrinkage attendant to processing treatments, phase transformations, annealing characteristics and other physical changes manifesting themselves in a change of a 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 extensive programming available to produce thermal cycles, complex processes can easily be simulated. The furnace is constructed of a multi-cavity alloy block surrounded by low thermal mass fibrous insulation. Four resistive heaters act as linear heat sources, and liquid nitrogen is employed for cooling. An instrument can be supplied with up to four active samples cavities, and up to four instruments can be clustered around one computer for concurrent operation.

-150°C to 300/500°C Up to 4 samples R&D or QC use Ideal for polymers ASTM

The digital displacement transducer 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. In special instances, an analog sensor is added with a proprietary automatically calibrating coupling mechanism to further increase resolution.

The instrument is based on the principle of the classical fused quartz dilatometer, without using cumbersome and expensive sample holder tubes. The design ensures that all quartz components are fabricated from the same stock. It also enhances temperature uniformity, rapid response, and alleviates the difficulties associated with placing thermocouples into the sample. System correction is performed digitally based on calibration test with NIST reference materials. The standard fused silica dilatometer components are readily interchangeable with ones made of a zero-expansion material to further enhance instrument sensitivity. System correction for these parts is automatically made in software. The system meets and in many respects exceeds requirements set forth in ASTM E-228 and D-696 Standards. Operation is very simple and rapid, yet extremely accurate. Due to the flexibility of the computerized operation, it can be used for the most demanding research as well as for simple quality control work. Sample changing and setup only takes a few minutes.

FEATURES COMMON TO ALL COMPUTERIZED INSTRUMENTS

The Unitherm™ line features fully computerized systems designed to measure the various thermophysical properties of solids. All instruments in this family of devices use the Windows™ 95 or later platform to interface the control computer. In most cases, multiple unit operation is possible.

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.

Computer and Peripherals

A current model PC can be provided with the instrument to carry out the control and data analysis functions. For specifics, please inquire at the time purchase of the device is contemplated.

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. Internal logic is included for thermal equilibrium (where applicable) and for optimized cycles.

Data Recording

Measured data is recorded in the form of page print-out 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 Thermocouple Linearization

Built-in system correction and calibration tables than can be verified or altered if desired are included. System correction can be altered, based on calibration runs with NIST standards or other references. All thermocouple signals are precisely linearized using look-up tables.

Data Reduction, Analysis, and Reporting

Stored data is automatically processed by statistical methods, either for equilibrium points only, (which are sorted out on user selected criteria), or for all points (such as with ramp heating, where applicable). The analysis includes polynomial curve fitting, evaluation of the equation at user selectable points or intervals, and tabulation of results, (such as percent expansion, average coefficient, and instantaneous coefficient, thermal conductivity, specific heat, 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

An extensive array of safety provisions ensure that operational malfunctions of each key part will not cause catastrophic failure of the system or destruction of the specimen. Open thermocouple, loss of water flow, four levels of furnace and sample over-temperature, and dead computer detection are among the functions that are continuously monitored. Certain ones will automatically shut down the equipment while others summon the operator via audio-visual indicators. Built-in diagnostic routines allow the operator to exercise and interrogate the failed system to determine the cause. All circuitry is homogeneously integrated on three circuit boards which can be swapped out in a matter of minutes for quick repairs.

To request a quote, please fill out our Request for Particulars form.
Specifications are subject to change without notice.