| EXPERIMENTAL FACILITIES |
| Research Calibrated Hot Box: |
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 The C-976 Research Calibrated Hot Box at the
University of Massachusetts has the capability of simulating both parallel and
perpendicular environmental wind directions on building assemblies, including fenestration
systems. The present hot box with an 8 ft. by 8 ft. test section has been redesigned,
fabricated and moved to a new environmentally controlled laboratory. The surround panel is
uniquely designed to accommodate all of the fenestration opening sizes designated by the National Fenestration Rating Council (NFRC).
The new design incorporates many of the state of the art features that can be found in
some of the hot boxes in the United States, Canada and Western Europe. Some of these
features are an HP 3852A Data Acquisition/Control Unit coupled with an IBM compatible 486 Personal Computer using
LabView data acquisition software.  This
second generation Research Calibrated Hot Box is capable of simulating a wide range of
conditions and accurately measuring the steady state thermal performance of a wide range
of building products and assemblies. It has the unique capability of providing valuable
research and development data on fenestration systems which can utilized in the current
ASTM hot box fenestration measurements standards development. |
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| Guarded Hot Plate: |
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An ASTM C177/C1045 compliant guarded hot plate is used for measurements of
material conductivity. This device has recently been designed and constructed. The hot
plate is fully instrumented and can also be operated by the new data acquisition system
described above.
Guarded Hot
Plate can measure:
homogenous materials
and
composite material
assemblies
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| HP Data Acquisition System |
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 A data acquisition/control system contains
various types of electronic equipment that measure, process, and analyze data acquired
from the user’s application. A data acquisition/control system can also control or
regulate the user’s application or process in response to the data obtained.
Figure 1 shows a data
acquisition/control system where these functions are performed by a mainframe, which it is
HP 3852A used in University of Massachusetts Research Calibrated Hot Box Data Acquisition
System. |
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The function of the data task is to
measure or count data supplied by the user’s application. On command, the mainframe
of the data acquisition system receives data from the user’s application through the
channels of various plug-in accessories. Often a transducer as shown in Figure 1 will be
connected between an application and the input to the mainframe of the data acquisition
system. A transducer is a device that converts a physical parameter (e.g. temperature)
into an electronic signal (voltage) the mainframe can measure. |
| As shown in Figure 1, the Data
Acquisition System (DAS) for the University of Massachusetts Research Calibrated Hot Box
is comprised of a Hewlett Packard (HP) mainframe (HP 3852A) and extender chassis (HP
3853A) data acquisition and control unit, an HP Vectra personal computer work station
loaded with LabView (version 3.0) for Windows (National Instrument Corporation 1994). |
| The mainframe and extender chassis
are capable of simultaneously performing 180 thermocouple/voltage measurements using nine
(9) 20-channel plug-in multiplexor accessories. The thermocouple and power measurement
system extension wires are directly connected to the multiplexors through a framed opening
in the laboratory wall. All thermocouple measurements are compensated with an electronic
voltage reference junction before converting to an actual temperature in degree centigrade
with an internal thermocouple material specific voltage/temperature function. The
mainframe and extender can be operated individually by using the front panel keyboard and
digital display. |
| The PC works as data acquisition
controller and data storage. Information is transmitted between the HP 3852A mainframe and
the PC controller through general-purpose interface bus (GPIB) communications. A GPIB
board, installed in the PC controller, is connected to the mainframe with an HP-IB cable.
A set of application programs written by LabView software, which is graphically based
real-time software, was used to control the various temperature and power measurements.
The PC sends commands to the mainframe in the required system format. Raw temperature and
power measurement data are returned to the LabView software environment for additional
calculations. The text code calculations and displays real-time average temperature and
power measurements, as well as, average component heat transfer results at 30 second scan
intervals to the PC screen and a user defined text output file. |
| A final total average of all of the
measurement data is calculated, and filed, upon completing the required test time period.
The length of test time is performed by the user defined scan number. A final test report
can then be generated based on the measurement results and in spreadsheet format. |
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