Thermal Analysis Laboratory
The thermal analysis laboratory offers extensive thermal analysis capabilities
through a complimentary set of state-of-the-art thermal analysis instruments. This
laboratory contains a DSC, DTA, TMA and DMA, all connected to and controlled by a single
UNIX-based computer. These instruments provide a valuable new resource to our research
programs by enabling us to conduct experiments ranging from basic analysis of chemical
reactions and phase transformation to the study of the creep behavior of materials.
System Controller
The system controller combines PC-based hardware with UNIX-based software (SCO
UNIX) to provide multitasking, multimodule, multiuser operation. This controller is ideal
for small laboratories which are running multiple thermal analyzers simultaneously. The
system is capable of real-time operation, enabling one to change tasks quickly and to
continuously monitor measurement parameters from any instrument. It provides fully
automated operation of each instrument and includes a unique "DOS task" for
simultaneous operation of DOS programs. Hardcopy output is provided by an HP 7550A pen
plotter.
Differential Scanning Calorimeter
A DSC measures the amount of energy absorbed or released by a sample as it is
heated, cooled or held at a constant temperature. Combined with a precise measurement of
the sample temperature a DSC provides a nearly complete assessment of the chemical
reaction or phase transformation. Our DSC is Perkin-Elmer’s DSC 7, a
power-compensated DSC which measures the energy of the reaction directly. It also uses
platinum resistance thermometers which makes temperature measurement more accurate and
repeatable. In addition, the low mass furnace makes it possible to heat the sample at
rates up to 500°C/minute, cool the sample quickly and respond more quickly to thermal
events. It also means that cycle times for each experiment are shortened considerably.
Selected specifications of the DSC 7 include:
Calorimetric Accuracy less than 1% with better than 1 microwatt sensitivity and 0.1% precision
Temperature Range: -170 to 723°C with 0.1°C accuracy and precision.
This DSC can be used with static or dynamic atmospheres of nitrogen, argon, helium, carbon dioxide, air, oxygen, and other gasses.
Differential Thermal Analyzer
A DTA measures the temperature difference between a sample and a reference
material as a function of temperature as they are heated, cooled or held at a constant
temperature. It records the temperature changes associated with endothermic and exothermic
chemical reactions or phase transformations, thereby fixing the reaction or transformation
temperature. Our DTA is the Perkin-Elmer DTA 7. It features high sensitivity,
automation, a broad temperature range, rapid heating and cooling and simplicity of
operation. It can even operate simultaneously as both a DTA and a TGA. Selected
specifications for this instrument include:
Calorimetric Precision of ±2%
Temperature Range: ambient to 1600°C with ±0.2°C precision
Heating/Cooling Rates: 0.1 to 100°C/minute heating rates and 20-30 minute cool-down times
The atmosphere can be either static or dynamic nitrogen, argon, helium, other inert or reactive gasses and vacuum.
High-Temperature Thermal Gravimetric Analyzer
A TGA measures the change in mass of a sample as it is heated, cooled or held
at a constant temperature. This instrument is basically a precisely controlled furnace
combined with a microbalance. TGAs are routinely used to study the quantitative separation
of components in a mixture and the decomposition of a material in a given environment. Our
TGA is Perkin-Elmer’s HT-TGA 7, a high temperature version of their TGA, boasting a
rugged but sensitive ultra-microbalance, a low mass furnace which permits rapid heating,
cooling and response to thermal events and automatic Curie point calibration routines
which ensure accurate temperature calibration. Selected specifications of the HT-TGA 7
include:
Balance: 0.1 microgram sensitivity with 0.1% accuracy and 10 ppm precision
Sample Size: up to 250 microliters
Temperature Range: 50 to 1500°C with ±5°C precision
Heating Rates: up to 100°C/minute
The HT-TGA also features forced air cooling for rapid cycling and a Pt-Pt10Rh thermocouple for temperature range, sensitivity and stability. The atmosphere can be static or dynamic nitrogen, argon, helium, carbon dioxide, air, oxygen, other gasses.
Dynamic Mechanical Analyzer
A DMA measures changes in the mechanical behavior (modulus, damping) as a
function of temperature, time, frequency, stress and a combination of these parameters. A
DMA can be used to determine the softening point of materials, perform creep experiments
and study changes in damping capacity and modulus as a function of temperature. Our DMA is
Perkin-Elmer’s DMA 7e. It boasts six operating modes, automatic calibration,
the ability to measure a wide range of moduli and furnace technology which allows
controlled multi-step heating, cooling or isothermal operation over a wide range of
temperature. Selected specifications of this DMA include:
Scan Modes: temperature, time, frequency and dynamic stress
Other Modes: creep recovery, creep ramp, constant force and constant length
Temperature Range: -170°C to 500°C
Heating Rates: 0.1 to 40°C per minute in 0.1°C increments
Displacement Range: 0.0001 to 24.000 mm
Displacement Sensitivity: 50 nm
Elastic Moduli: 1 kPa to 3,000 GPa
Frequency Range: 0.01 to 51.0 Hz in 258 steps
Amplitude Range: 0.0002 to 1.3000 mm
tan(delta): 0.0001 to 9.9999
Stress Range: 1 kPa to 3,000 GPa
Force Range: 0.003 to 8.000 N
Other Equipment
This laboratory includes a manifold which allows one to select one of two purge gases and
to accurately control their flow rates. The flow of gas to each instrument is
controlled separately, allowing one to operate multiple instruments simultaneously.
Also in the laboratory is a microbalance (101 gram capacity, 0.1 mg readability, 0.1 mg
repeatability, 0.2 mg linearity) which is used to weigh the specimens.
Division of Materials Science
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Updated on June 25, 2001
Department of Chemical Engineering and Materials Science
University of California, Davis
Davis, CA 95616
USA
Phone: 530/752-0400
Web: www.chms.ucdavis.edu