| The Cannon Thermoelectric
Bending-Beam Rheometer performs low-temperature
flexural creep stiffness measurements on asphalt
binders as specified in ASTM D 6648, AASHTO, and
SHRP methodology.
The TE-BBR achieves
temperatures from ambient to -36°C using the
latest in Peltier technology. Bath fluid, which
does not circulate outside the TE-BBR, is cooled
by solid-state cooling modules surrounding the
bath. Heat is dissipated from the hot side of
the thermoelectric modules by circulating a
mixture of water and antifreeze through an
Air/Water Heat Exchanger (not shown in
photograph). This arrangement facilitates rapid
cooling and eliminates costly and potentially
hazardous refrigerants.
The TE-BBR is capable of controlling temperature within
0.03°C, a precision far exceeding the requirements of current flexural creep
test methodology for asphalt binders. The instrument measures specimen beam
deflection to within 0.155 microns (1550 Angstroms) and force to within 0.147
milliNewton (0.015 gram). The TE-BBR will measure specimen beam loads from 0 to
450 grams.
Data acquisition is accomplished internally with
information transferred to a host computer via a standard RS-232 interface. The
TE-BBR software for Windows® permits computer-controlled temperature selection
and graphic and numeric output of test data. The operational firmware is
upgradeable - updates or changes may be downloaded via the computer. The current
software includes extensive reporting of load variances throughout the test
period and more detailed verification procedures with 2-gram weights.
The TE-BBR controls air pressure with four pneumatic
pressure regulators, permitting the operator to adjust main input line pressure,
air bearing pressure, and pressure supporting the loading shaft for a "Zero”
condition and a "Load" condition.
A magnetic stirring bar at the bottom of the bath vessel
circulates bath fluid to ensure uniform temperature distribution throughout the
bath. The speed of the stirring bar rotation is adjustable.
Computer not included. An IBM-compatible
computer with a pentium processor and Windows 95/98/NT/XP, SVGA or better
monitor, CD-ROM drive, 32 MB RAM, a serial port, and a hard disk with 200
megabytes available disk space is required. |
