Digitizing Waveform Recorders Research Articles

Random noise test of ADCs with a sinusoidal stimulus

The recommended random noise test for analogue to digital converters (ADCs), as stated in the IEEE 1057 Standard for Digitizing Waveform Recorders, suggests the utilization of a triangular signal as the stimulus for the ADC under examination. However, we will demonstrate that an alternative option of employing a sinusoidal stimulus signal is equally feasible. This substitution provides enhanced flexibility during the testing process and enables the utilization of sine fitting algorithms.

Random noise test of analog-to-digital converters

The random noise test of analog to digital converters recommended by the IEEE 1057 Standard for digitizing waveform recorders is studied. The heuristically derived expression presented for the estimation of the random noise standard deviation is experimentally validated. The standard suggests a triangular stimulus signal. Here we will show how to use a sinusoidal stimulus signal to carry out the test. The influence of stimulus signal offset and amplitude on the estimation error is also analyzed and an expression is presented to compute the minimum amplitude value that guarantees an upper bound on the estimator bias.

A glimpse at fifty-one years in acoustic emission

After 51 years continuously involved in acoustic emission (AE) testing and research, it has been interesting to look back over five decades. The equipment available in the early 1970s was primitive compared to now. At the start of that decade, only one, recently established, commercial company sold AE measurement equipment, and other useful equipment was internally built or adapted from other technologies. Further, the data that came from an AE monitored test was simply the number (counts) of penetrations of a fixed one-volt threshold expressed as an increasing total or a rate and recorded on an x-y plotter. The purpose of this “glimpse” is to present advances both within the author’s research as well as those that were adopted from others research that were viewed as moving AE technology forward. This “glimpse” is not intended to be comprehensive, instead it is limited to aspects the author was involved in. Among the topics to be covered are advances such as understanding hydraulic test machine continuous noise, true rootmean-square (RMS) voltage measurements, inclusion particle fracture or decohesion, tension versus compression testing for unflawed metal samples, the pencil lead break, an acoustic emission signal simulator, broadband sensors, digital waveform recorders, large transversedimensioned plates, absolutely calibrated flat-with-frequency AE sensors, finite element modeling (FEM) in isotropic materials, validation of FEM, computer-based digital AE systems, intensity of frequency versus time of AE signals, superposition of group velocity results and FEM beyond the case of dipoles in an isotropic plate.

The IEEE Technical Committee 10-The Waveform Generation, Measurement, and Analysis Committee: Update 2021

The IEEE Technical Committee 10 (TC-10), the Waveform Generation, Measurement, and Analysis Committee of the IEEE Instrumentation and Measurement Society (IMS), supports the advancement of industries and other entities that research, develop, manufacture, and use technologies and instruments that generate or acquire signals. These signals are ubiquitous and used in many technologies, such as, but not limited to, communication, computing, transportation, medicine, entertainment, manufacturing, and agriculture. The TC-10 work, therefore, impacts everyone. Because the TC-10 is a developer of documentary standards, the TC-10's goal is achieved by fulfilling, as best as possible, the global need for standardized terms, test methods, and computational methods that are used to describe and measure the parameters that describe the performance of signal generators and waveform recorders and analyzers. The TC-10 has developed and maintains the following documentary standards: IEEE Std 181–2011, Standard on Transitions, Pulses, and Related Waveforms [1]; IEEE Std 1057–2017, Standard for Digitizing Waveform Recorders [2]; IEEE Std 1241–2010, Standard for Terminology and Test Methods for Analog-to-Digital Converters [3]; IEEE Std 1658–2011, Standard for Terminology and Test Methods for Digital-to-Analog Converters [4]; IEEE Std 1696–2013, Standard for Terminology and Test Methods for Circuit Probes [5]; and IEEE Std. 2414–2020, Standard for Jitter and Phase Noise [6]. Additional information on these standards and the TC-10 can be found in [7], [8].

The IEEE Technical Committee 10: The Waveform Generation, Measurement, and Analysis Committee

The IEEE Technical Committee 10 (TC-10), the Waveform Generation, Measurement, and Analysis Committee of the IEEE Instrumentation and Measurement (I&M) Society, seeks to support the advancement of industries and other entities that research, develop, manufacture, and use technologies and instruments that generate or acquire signals. These signals are used in most if not all interfaces between humans and technology, such as, but not limited to, communication, computing, transportation, medicine, entertainment, manufacturing, and agriculture. In fact, it is very difficult to identify a human activity, other than the primitive, that is not in some way touched by electronics. So, in the broadest interpretation of the goal of the TC-10, it could be said that the TC-10 impacts everyone. Because the TC-10 is a developer of documentary standards, the TC-10's goal is achieved by fulfilling, as best as possible, the global need for standardized terms, test methods, and computational methods that are used to describe and measure the parameters that describe the performance of signal generators and waveform recorders and analyzers. The TC-10 has developed and maintains the following documentary standards: IEEE Std 181–2011, Standard on Transitions, Pulses, and Related Waveforms [1]; IEEE Std 1057–2017, Standard for Digitizing Waveform Recorders [2]; IEEE Std 1241–2010, Standard for Terminology and Test Methods for Ana-log-to-Digital Converters [3]; IEEE Std 658–2011, Standard for Terminology and Test Methods for Digital-to-Analog Converters [4]; the IEEE Std 1696–2013, Standard for Terminology and Test Methods for Circuit Probes [5]; and the IEEE Std 2414–2020, Standard for Jitter and Phase Noise [6]. Additional information on these standards can be found in [7].

The documentary standards of the IEEE technical committee 10

Global trade relies on the ability to reproducibly and accurately communicate the performance of products and to support these attestations. This standardization is essential for accurate, reproducible, reliable, and communicable characterization of the performance of these devices, to support technology and product advancement, product comparison and performance tracking, and device calibration and traceability. Standard terms and definitions, reproducible test methods, and accurate computational procedures are necessary for this communication and facilitate economic growth and technology evolution through the common understanding of technology. The IEEE Technical Committee 10 (TC-10), the Waveform Generation, Measurement, and Analysis Committee of the IEEE Instrumentation and Measurement Society (IMS), fulfills the global need for standardized terms and test and computational methods for describing and/or measuring the parameters that describe the performance of signal generators and waveform recorders and analyzers. The TC-10 has developed and maintains the following documentary standards: IEEE Std 181-2011, “Standard on Transitions, Pulses, and Related Waveforms” [1]; IEEE Std 1057-2017, “Standard for Digitizing Waveform Recorders” [2]; IEEE Std 1241-2010, “Standard for Terminology and Test Methods for Analog-to-Digital Converters” [3]; IEEE Std 1658-2011, “Standard for Terminology and Test Methods for Digital-to-Analog Converters” [4]; and the IEEE Std 1696-2013, “Standard for Terminology and Test Methods for Circuit Probes” [5]. In development is the IEEE Draft Std P2414 “Draft Standard for Jitter and Phase Noise.” The TC-10 comprises an international group of electronics engineers, mathematicians, professors and physicists with representatives from national metrology laboratories, national science laboratories, component manufacturers, the test instrumentation industry, academia, and end users. The status of the TC-10 standards is described herein.

Evaluating the Uncertainty of Digitizing Waveform Recorders Coherently With the GUM

The performance parameters defined in the IEEE Standard 1057–2007 do not specify the standard uncertainty of the reconstruction levels of digitizing waveform recorders. Not knowing the standard uncertainty of the reconstruction levels affects, in turn, the evaluation of the uncertainty of a number of measurement approaches, based on digital signal processing techniques, which utilize the data collected by a digitizing waveform recorder as the input data. A method to evaluate the uncertainty of memoryless waveform recorders embedded in off-the-shelf digitizing oscilloscopes is proposed here. The method is based on an experimental approach that can be carried out anytime the input signal is repetitive, the frequency response of the oscilloscope can be considered flat, and the dynamical effects are negligible. To qualify the proposed method, the uncertainty estimation obtained by applying it in several experiments is compared with that gained by means of a B-type evaluation.

A novel approach to reliable determination of surge armature current of a synchronous machine

Calculation of a short circuit current of a symmetrical fault in a high-power synchronous machine in accordance with national standards is time-consuming and imprecise. The process involves multiple graphic operations and a triple transition from an analog transient process to its discrete form and back. As a result, optimizing procedures cannot be applied to transient identification techniques that meet national standards and it is impossible to compensate for random factors in the identification process. Therefore, a surge current derived from experimental data is not adequate for transients in high-power synchronous machines. Modern equipment for recording of short-term transients solves many processing problems. Express determination of a surge current is obtained using a digital waveform recorder, which allows precise calculation of 50-Hz peaks and discrete representation of the 100-Hz component of the transients. This method of information extraction and processing replaces all the time-consuming graphic operations of the national standards. Results of a study of a 110-MW synchronous machine based on laboratory tests for various stator voltages are presented. The study has confirmed the viability of the proposed approach for express determination of a surge current without the need to determine the parameters of transients.

Word error rate measurement uncertainty estimation in digitizing waveform recorders

The paper proposes a method to measure the Word Error Rate (WER) affecting digitizing waveform recorders, suitable to be included, as addendum, into the IEEE Std.1057. In particular, a reliable estimation of the confidence interval and the design of efficient test sessions are provided. The proposed method has been experimentally verified by means of two WER test setups. Test results, carried out by means of WER measurements on actual digitizing waveform recorders, have been compared to those achieved by implementing the method described in the IEEE Std.1057.

Estimating the Uncertainty in the Frequency Domain Characterization of Digitizing Waveform Recorders

New propagation formulas for the uncertainty evaluation for the characterization of digitizing waveform recorders are proposed in this paper. The frequency domain figures of merit, as defined in IEEE Std. 1057, have been considered to present useful addenda to the standard. The proposed formulas have been validated on simulated and actual signals.

A low power and high resolution data logger for submarine seismic monitoring

The design, implementation and characterization of a digital waveform recorder for ocean bottom seismic monitoring is here reported. The system is capable of synchronously acquiring, and logging on a flash memory bank, four high resolution signals. Thanks to a very careful design of the system architecture and by using robust digital signal processing techniques, two main conflicting issues have been addressed: a high dynamic range, better than 120 dB, usually obtained with high energy demanding converters, and a power consumption as low as 250 mW, hence allowing to easily increase the time of a continuous submarine monitoring session up to 3 months.

IEEE 1057 Jitter Test of Waveform Recorders

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The jitter test of waveform recorders and analog-to-digital converters (ADCs) is traditionally carried out using one of the methods recommended in the IEEE standard for digitizing waveform recorders, i.e., IEEE Standard 1057. Here, we study the uncertainty of one of those methods, point out the bias inherent to the estimator recommended for measuring the ADC jitter, and suggest an alternate estimator. Expressions are also presented for the determination of the precision of a given estimate from the number of samples used, the standard deviation of the additive noise present in the test setup, the jitter standard deviation, and the stimulus signal parameters. In addition, an expression for the computation of the minimum number of samples required to guarantee a given bound on the estimation uncertainty is presented, which is useful in optimizing the duration of the test. </para>

Black-box identification of digital waveform recorders

The paper presents an overview on the problem of waveform recorder characterization, stressing the opportunity of working out a standard for the model identification of a recorder. As a concrete contribution to this project, the authors propose a unified complete behavioral model for single-channel data acquisition systems, discuss the suitability of known test methods for its identification, and draw some guidelines for the construction of a complete identification procedure.

A second look at IEEE Std 1057 — IEEE standard for digitizing waveform analyzers

In the world of engineering, little stays the same. IEEE Std 1057, the IEEE Standard for Digitizing Waveform Recorders, has been in use for over 5 years, and it is time to reevaluate it. This paper discusses in detail the goals of this reevaluation and solicits help from the international community in achieving those goals.

New standards at NIST based on digital techniques.

The ability to accurately characterize the linearity, effective bits, step response, and other properties of analog-to-digital converters (ADCs), waveform recorders, and high-speed digitizers is critical in many measurement applications, including some electroacoustical ones. Test methods and techniques have been developed at NIST for evaluating the performance of high-resolution (up to 18 bits), high-accuracy (to 2 ppm) ADCs and digital-to-analog converters (DACs), as well as 4- to 12-bit high-speed (up to 500 Msamples/s) ADCs, typically used in sampling oscilloscopes and waveform recorders. Several of these NIST-developed methods have been incorporated in the recent IEEE Std. 1057 Trial Use Standard for Digitizing Waveform Recorders (July 1989). Precision DACs having small linearity errors can be used to provide reference electrical waveforms. By using a pair of such DACs, a 2-Hz to 50-kHz audio frequency phase angle calibration standard was developed at NIST that demonstrated the feasibility of generating dual sinusoidal waveforms with a relative phase difference resolution of about 2-mdeg and an accuracy of better than 10 mdeg. With careful attention to the fidelity of each step in the waveform, a dual-DAC approach for interleaving the small steps of the output waveform has formed the basis for an rms ac voltage standard with a frequency range from less than 1 Hz to 50 kHz, good to an overall rms uncertainty of 20 ppm.

AC power disturbance detector circuit

The authors describe the design, construction, and performance of a circuit that detects transient disturbances on low-voltage AC supply mains. Such disturbances include reactive loads, large departures from the nominal RMS voltage, severe harmonic distortion, and outages. While this circuit was designed for use on single-phase mains, the primary side of the isolation transformer could be connected between one three-phase line and neutral. The disturbance detector circuit can be used to trigger a digital waveform recorder, as in the present application, or to operate a counter circuit to simply record the occurrence of a disturbance.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Applications of a multichannel digital waveform recorder with mixed and switchable sampling rate

A multichannel digital waveform recorder (MDWR) with a mixed and switchable rate is described. By using a synchronous clock and flexible triggering facilities, good phase relationship between fast and slow channels can be maintained. In switch sampling-rate applications, a switchable multistage digital decimating filter (MDDF) can be used to prevent aliasing when sampling at the slow rate and maintaining phase continuity at the sampling-rate switch-over point.

Automation of a stopped-flow spectrophotometer for the determination of reaction-rate parameters. Part I

A stopped-flow spectrophotometer was automated using a digital transient waveform recorder interfaced to a commercial 8-bit microcomputer. An assembly language program was used to acquire the kinetic data from the transient waveform recorder. A non-linear least-squares program was used to determine the rate constants from the stopped-flow kinetic data. The performance of the system was evaluated using electronic simulation and reaction rate data from the reaction of 2,6-dichlorophenolindophenol with ascorbic acid. The effect of varying the number of data samples on the calculated rate constant was investigated.

Impulse duration: A new instrument for its measurement

An instrument is described which, when used with a ‘peak hold’ reading sound level meter, will measure the durations of acoustic impulses in accordance with the Atherley and Martin and CHABA criteria for hearing damage risk to impulsive noise. The instrument is small, lightweight, can be battery powered and is designed for field use. Comparison tests show that the impulse duration meter gives more accurate and repeatable results than the oscilloscope trace photograph method or the digital waveform recorder method of impulse duration assessment. By using the instrument with a suitable impulse source reverberation time, measurements may be conducted.