Mobile Instrumentation Data Acquisition System (MIDAS)
Doug Ammerman, (505) 845-8158
The Mobile Instrumentation Data Acquisition System (MIDAS), developed by Sandia National Laboratories for the U.S. Department of Energy, provides on-site data acquisition of containers that transport radioactive materials during impact, puncture, fire, and immersion tests.
MIDAS is a self-contained data acquisition facility in a 13.4-m (44 ft.) trailer,|
which is equipped with structural and thermal data acquisition systems.
MIDAS is a self-contained, fully automated data acquisition facility equipped with structural and thermal data acquisiton systems. It is capable of collecting package data from a variety of piezoresistive measurement devices. Some of the onboard self-diagnostic features include data analysis capabilities, graphical software interface and communications center. The major features of the MIDAS system enable it to collect information and to analyze and display acquired data shortly after an experiment.
Quality assurance and documentation play an important part in the MIDAS program. A system documentation package is provided with the system, including computer software documentation, system diagrams and procedures, equipment specifications, calibration records, and operation and maintenance manuals. A record of equipment parameters and performance can be produced, providing a computer-generated audit trail. Trained MIDAS operating personnel are also provided with the system.
MIDAS structural and thermal data acquisition systems acquire data from measurement devices.|
Diagnostic equipment verifies system performance. Other systems support MIDAS's data measurement capabilities.
Testing radioactive material packages requires data collection to determine the structural integrity of radioactive material packages. MIDAS can collect 72 channels of time-domain structural data from any combination of piezoresistive measuring devices, including accelerometers, strain gages, strain-gaged bolts, and pressure transducers. These devices are commonly used to measure package response to regulatory impact, puncture, and immersion tests.
MIDAS can also acquire 100 channels of thermal data from type-K thermocouples, which are used to measure changes in package temperatures during thermal experiments.
MIDAS is a fully automated data acquisition system. Physical tasks performed manually in other systems are performed electronically by the structural system's matrix switching device, which routes signals to and from system components. This capability eliminates potential human error and verifies the connection paths between components. Also, the central system processor, a 32-bit workstation server configured with a Pentium III 550 MHz processor, supports data acquisiton control and performs analysis functions on the acquired data.
The MIDAS onboard diagnostic system verifies that data acquisition components are functioning correctly. This diagnostic system can verify equipment calibration and characterize component performance. Before an experiment, the diagnostics system can perform a system integrity test by inserting a known signal (from MIDAS's library of waveforms) and monitoring that signal between system components. Thus MIDAS can verify system integrity before an experiment
Structural data from measurement devices is routed through MIDAS's matrix switch, which is used to distribute data to other structural system components.
The data analysis capabilities of MIDAS feature reduction of raw, voltage-based data from measurement devices to their true engineering unit forms. In addition, MIDAS can perform other data processing and display functions based on documented signal-processing algorithms (Stearns, S.D., and R.A. David, 1988. Signal Processing Algorithms, Englewood Cliffs, New Jersey, Prentice Hall, Inc.). Data from MIDAS can also be made available to other systems on computer media.
MIDAS measurement capabilities are supported by a timing system that can send or receive precise time and frequency information. The onboard communications center provides remote-site communications and audio-visual review of tests. A black-and-white or color printer displays waveform output from acquired test data. Other features include onboard air conditioning and heating, a halon fire protection system, lightning protection, and either commercial or motorgenerated power capabilities.
MIDAS Technical Specifications
Structural Data Acquisition
72 channels of time-domain data
Bandwidth to 100 KHz
500 KHz bandwidth at -3 db
12 bit resolution plus signal and status
100 thousand to 1 million samples per second
Up to 12 million sample capacity per channel
Thermal Data Acquisition
100 channels of type-K thermocouple data
Arbitrary waveform synthesizer
Pentium III 550 MHz processor
Redhat's Linux® operating system
512 Mb random access memory (RAM)
90 GB hard disk storage
MIDAS Linux®-based operator software, customized for data acquisition tasks, features on-screen graphics displays based on a system of color display windows. The user-friendly interface utilizes the MIT X window system. On-screen options for both data acquisition and analysis functions are selected by means of a mouse or keyboard.
The MIDAS window system allows the operator to perform tasks in a sequence suited for data acquisition as opposed to performing individual task-specific functions. Also, many tasks that require manual operation in other data acquisition systems are accomplished through the window system in MIDAS.
MIDAS operators can perform data acquisition tasks by choosing options displayed on MIDAS's color window display system. These options are selected by means of a mouse or keyboard.