Showing papers on "Data acquisition published in 1977"

Data smoothing using low‐pass digital filters

Abstract: With the increasing use of computer‐controlled data acquisition systems which record data in digital form, there has developed a need for techniques which perform a general smoothing process on digitized experimental data. This processing enables the experimentalist to eliminate or greatly reduce the amount of high‐frequency noise in order to obtain as accurate and clean representation of the true phenomenon as is consistent with his measurement accuracies. This filtering or smoothing process should be as simple and efficient (least amount of arithmetic per data sample) as is consistent with the experimental situation. The basic concepts of low‐pass filters are discussed and four different low‐pass filter design procedures are described, each with its own particular smoothing properties. These design procedures give directly the coefficients of a symmetrical weighting sequence having the desired passband width and the desired high‐frequency noise rejection. The uses of the filters are illustrated with examples and the fortran code for implementing each of the design procedures is given in an Appendix.

Data acquisition system

Abstract: A data acquisition system utilizing a microcomputer and incorporating a plurality of monitors each adapted to produce an electrical signal indicative of a physical condition of apparatus to be monitored. The electrical signals are fed via multiplexing equipment and analog-to-digital converters into the microcomputer which is equipped with print-out means. The system is such that the level of any one or all of the signals from the respective monitors can be printed out as well as a change in the condition of any signal. Means are incorporated into the computer for calculating and printing the trend (i.e., the slope of a plot of signal amplitude versus time) of a succession of stored signals from any monitor which would indicate a probable malfunction of a device being monitored and the probable time to failure. In the case where the signals from the monitors comprise vibration signals, the system performs an automatic frequency spectrum analysis whenever a probable or actual malfunction is detected.

Photo‐acoustic spectroscopy of solids

Abstract: A method is presented by which photo‐acoustic spectroscopy of solids may be performed. Criteria for the light sources, sample chambers, and data acquisition systems are discussed. The dependence of the photo‐acoustic signal on various experimental parameters is explored, and some of the applications of this new technique are discussed.

Data acquisition systems

Abstract: A data acquisition system for a hot metal handling operation uses optical transmission of data from a plurality of hot-metal stations to a control computer. Preferably the computer transmits control instructions to operators via the optical link. In an aluminium pot-line arrangement the mobile transceiver may be mounted on the service crane.

Solid state data recorder

Abstract: A solid state data recording system for storing multichannel analog data. is low power system has characteristics similar to a high performance analog tape recorder but has no moving parts and can be easily ruggedized for severe environmental conditions. In the "write" mode analog data are sampled and converted to digital bits of information. These individual bits are stored in a solid state storage medium by coded enabling and address information provided by a controller. The information is played back by reading out these digital bits, converting them to analog form, and then demultiplexing them to their original channels.

DIGITAP-An On-Line Acquisition and Processing System for Instantaneous Engine Data-Applications

Abstract: A versatile data acquisition system for engine pressure-time history is described The on-line system utilizes a 12-bit sample-and-hold A/D converter in conjunction with a mini-computer The computer controls this acquisition process and performs data processing to generate the desired results The time base for the system is generated by a shaft mounted disk and photoelectric sensors On-line selection based on predefined criteria of particular interest is software implemented Statistical data are available such as the standard deviation and the histogram of maximum pressure Teletype print, XY plot and punched paper tape are standard outputs Among the wide variety of potential applications of this system, some actual examples in such areas as cyclic variation, knock, friction losses and heat transfer are given

Variable angle photoelectron spectrometer

Abstract: The design, construction, and performance of a spectrometer for measuring the angular and energy distributions of electrons photoejected by rare gas resonance light is described. Results using 584.4‐A photons from a helium lamp are reported. Flexibility of instrumental design allows for the use of other light sources. A 180° hemispherical electrostatic electron energy analyzer is rotatable about the center of an enclosed sample chamber. The instrument is highly automated, with an on‐line computer used to control the detector angle and the data acquisition and reduction. This automation is required by the long and continuous data acquisition.

Data acquisition system for computed tomography

Abstract: The radiation source and detectors in a computed tomography system translate and/or rotate with varying velocity profiles. Radiation transmission data is measured and sampled at a high rate, the sample points being equally spaced in the time domain. The data samples are then smoothed and interpolated, using a high order polynomial fit, to provide input signals for an image reconstruction algorithm which are representative of transmission values at points which are evenly distributed in space.

The client-oriented data acquisition process (CODAP-77).

Abstract: This report describes the data collection system named Client Oriented Data Acquisition Process (CODAP) and illustrates its application.

A system for automatic acquisition of three-dimensional data

Abstract: This paper presents the design of a three-dimensional data acquisition system based on multiple, single-dimensional optical sensors. The system can operate in any of three modes:(1) the tracking of multiple, independent, point light sources(2) the automatic digitization of opaque surfaces(3) the real-time tracking of an unmarked moving object (e.g., tip of user's hand).The design offers such advantages as a lensless sensing system, a minimum reliance on analog measurements, an ease of upgrading to higher precision measurements, an ease of portability, an adjustable field of view, and the ability to operate under normal ambient light conditions. A network of microprocessors is incorporated to minimize processing delays and thus increase data acquisition rates. In its initial application the system will digitize the cranio-facial surfaces of candidates for reconstructive surgery.

On the Uses of Computers for Experimental Control and Data Acquisition

Abstract: even more informal social activities of recreation. Chinked in between these group activities are periods of individual problem solving in which we seek &dquo;How shall I ask for a raise?&dquo; or &dquo;Which person in -class shall I approach to get the notes on the lecture I missed?&dquo; or &dquo;Oh lord! I am in the dummy-how do I get back into my hand?&dquo; Men have invented many institutions to help regulate group activities. For example, the organization chart of the company, the group class assignment, the rules of bridge, and the concept of a personal budget. Academics build models of individual and group problem solving in order to aid in the understanding of how these complex processes work. 1

The NBS Network Measurement System

Abstract: The NBS Network Measurement System reipresents the implementation of an approach to the measurement of interactive computer networks, teleprocessing systems, and network series which focuses on the service delivered to users rather than on the internal operating efficiency of the system. The information obtained aids users in the quantitative evaluation of such systems and services. The Network Measurement System consists of a data acquisition System and a separate set of data analysis programs. This paper describes the approach to network measurement taken by this system, the models of user-system dialogue employed, and technical summary of, the implementation of the data acquisition system and the data analysis programs.

Autoranging in High Speed Data Acquisition Systems

Abstract: ABSTRAC This paper is a presentation of various types of autoranging amplifiers and methods of incorporating them into fast digital data acquisition systems. The advantages and drawbacks of each type of autoranging method are examined. An example of fast autoranging using rapid scan square wave polarography is presented in which trace amounts of materials are detected in the presence of large amounts of other electroactive species.

A low-cost signal averager and data-acquisition device.

Abstract: A low-cost data-acquisition device, which can be used as a signal averager or temporary data buffer, is described. It consists of 1) an input stage built with a multiplexer, sample-and-hold amplifier, and an analog-to-digital converter; 2) a memory section made of static shift registers with recirculate capability; 3) an output stage built with a demultiplexer and a digital-to-analog converter and, 4) a control module which provides the logic signals to operate the machine. Basic diagrams are presented and several applications are described.

A microprocessor-based data acquisition and processing system for studying the kinematics of labor

Abstract: The design, development and preliminary evaluation of a microprocessor-based data acquisition and processing system which continuously and simultaneously acquires signals of fetal heart rate, intrauterine pressure, uterine cervical dilatation and variables for calculation of spatial position or pathway of fetal descent are presented. The project consists of four phases: 1) Design and fabrication of the data acquisition system; 2) Development of signal processing and pattern recognition techniques using a PDP-11/45 based signal processing system; 3) Transfer of algorithms produced in phase 2) to the microprocessor-based data acquisition system; and 4) Long term physiological study of acquired data directed toward obtaining more conclusive diagnostic or clinical results. This paper reports the development of the first two phases.

Data acquisition and display device

Abstract: A data acquisition and display device for acquiring and displaying the time history of the variations in an analog value includes digital circuitry which employs a staircase voltage generator operated at a first frequency to quantize a range of analog voltages which correspond to the expected variations in the analog value. When the staircase voltage equals an analog voltage corresponding to the instantaneous value of the analog value, a memory device is conditioned to receive data corresponding to the staircase value. The memory acquires the data at a second frequency selected by the operator to acquire a fixed number of data inputs over a selected time period for which the time history is desired, and the circuitry automatically terminates data acquisition when the fixed number of data inputs is acquired. The data is read out at a third frequency selected by the operator.

Automatic data acquisition of power network overvoltages and of laboratory impulses

Abstract: This paper presents two automatic systems for the acquisition of the overvoltages : in the network with an original device and in the two high voltage laboratories of ELECTRICITE DE FRANCE with a minicomputer. The aims of these two equipments are explained. A description of their operating conditions and capabilities is given and the criterions which led to the chosen solutions are pointed out. Finally, one reports the acquired experience.

Interface between a Biomation 8100 and a remote computer for data acquisition in TEA‐CO2 laser‐induced photochemistry

Abstract: The experimental setup for data acquisition in infrared photolysis experiments is described. The data was obtained with a Biomation model 8100 transient recorder interfaced to a remote computer via a serial line. The interface was built from inexpensive parts and the circuit is described in detail. The described method of data acquisition may be used where high rf noise renders conventional multichannel analyzer techniques impractical.

A data acquisition and handling system for the measurement of radial plasma transport rates

Abstract: A microcomputer serves as a programmable interface between high frequency transient recorders and a digital incremental tape recorder. An interactive program stored in the microcomputer permits the operator to enter various experimental parameters in response to queries from the system. The microcomputer then stores both the experimental parameters and the raw digital data on tape for later processing by a general purpose computer.

A Command Language Based Data-Acquisition and Analysis System for Low Energy Physics

Abstract: An open-ended Command Language based data-acquisition and analysis system for low energy nuclear physics applications is described. The system is designed to accommodate user-written command functions as well as standard system functions. The system insulates users from each other so that a user has access to only his particular functions and those of the system. Features include a "Help" function, free format input with prompting for omitted parameters, an extensive error message facility, and dynamic memory management. Particular effort has been directed at making the system as natural and logical as possible to the physicist/user while giving him maximum flexibility in controlling his experiment. The incorporation of reasonable defaults, free format input, and extensive checking of input with appropriate diagnostics is essential. Although this paper details a system developed for nuclear physics applications, the techniques are applicable to a variety of data acquisition and control applications.

Modeling of water distribution systems

Abstract: The objective of water distribution control is to provide an adequate level of service at all points in the system economically under varying conditions of loading. With the increase in size and complexity of water distribution systems, the need for economic and reliable operation makes it necessary to use digital computers for data acquisition and supervisory control. This paper considers the application of mathematical models for simulation and optimization of the distribution system operation. With these models, it is possible to analyze the system data to perform operations planning and system load management.

Self-contained data acquisition device

Abstract: A self-contained data acquisition device or probe capable of monitoring any physical function that can be translated into an analog or digital signal. The data acquisition probe is coupled to a separate translator whereat the stored analog or digital voltage signals are transferred to the translator to be coupled to a display device for displaying the voltage signals.

Multichannel analog transient acquisition system

Abstract: A 16‐channel data acquisition system MATAS‐16 capable of receiving data with a sampling frequency up to 40 MHz has been built to process the signals from measurements on the Texas Turbulent Torus experiment. To avoid the necessity of using a number of fast (and expensive) digitizers, the signals are first stored in serial analog memories. Subsequently, they are sequentially read out, digitized, and stored in digital memory. These data are then transmitted to the computer for analysis and are graphically displayed. Delayed trigger, post‐trigger, pretrigger, and change of sampling frequency during the data acquisition are also provided.