High Resolution Time-Interval Measurement Systems Applied to Flow Measurement

Grzelak, Sławomir; Kowalski, Marcin; Czoków, J.; Zieliński, M.

doi:10.2478/mms-2014-0008

Cited by 11 publications

(7 citation statements)

References 6 publications

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“…Implementation of the TIMM inside the programmable structure [16] allows to decrease the time between projected and finished device. It is known that the hardware is modified during the design process, while the programmable structures can be programmed easily in a complete system without intervention into hardware.…”

Section: Discussionmentioning

confidence: 99%

Ultrasonic Flow Measurement with High Resolution

Grzelak

Czoków

Kowalski

et al. 2014

Metrology and Measurement Systems

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The ultrasonic flowmeter which is described in this paper, measures the transit of time of an ultrasonic pulse. This device consists of two ultrasonic transducers and a high resolution time interval measurement module. An ultrasonic transducer emits a characteristic wave packet (transmit mode). When the transducer is in receive mode, a characteristic wave packet is formed and it is connected to the time interval measurement module inputs. The time interval measurement module allows registration of transit time differences of a few pulses in the packet. In practice, during a single measuring cycle a few time-stamps are registered. Moreover, the measurement process is also synchronous and, by applying the statistics, the time interval measurement uncertainty improves even in a single measurement. In this article, besides a detailed discussion on the principle of operation of the ultrasonic flowmeter implemented in the FPGA structure, also the test results are presented and discussed.

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Section: Discussionmentioning

confidence: 99%

Ultrasonic Flow Measurement with High Resolution

Grzelak

Czoków

Kowalski

et al. 2014

Metrology and Measurement Systems

Self Cite

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“…The results are not perfect due to a number of factors, mainly inability to accurately determine the crystal temperature and keep it stable. Effects of thermal hysteresis [23] and thermal gradient, among others [5,6], contribute to the error. The thermal hysteresis means that the crystal resonant frequency is not only a function of its current temperature, but depends on the history of temperature variations as well.…”

Section: Frequency and Frequency Vs Temperature Calibrationmentioning

confidence: 99%

“…Variations are, naturally, dependent on the observation period. Therefore, they are usually divided into shortterm and long-term instabilities [5]. The expression "intermediate-term" is also used.…”

Section: Quartz Crystal Resonant Frequency Issuesmentioning

confidence: 99%

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Simultaneity Analysis In A Wireless Sensor Network

Malović¹,

Brajović²,

Mišković³

et al. 2015

Metrology and Measurement Systems

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An original wireless sensor network for vibration measurements was designed. Its primary purpose is modal analysis of vibrations of large structures. A number of experiments have been performed to evaluate the system, with special emphasis on the influence of different effects on simultaneity of data acquired from remote nodes, which is essential for modal analysis. One of the issues is that quartz crystal oscillators, which provide time reading on the devices, are optimized for use in the room temperature and exhibit significant frequency variations if operated outside the 20-30°C range. Although much research was performed to optimize algorithms of synchronization in wireless networks, the subject of temperature fluctuations was not investigated and discussed in proportion to its significance. This paper describes methods used to evaluate data simultaneity and some algorithms suitable for its improvement in small to intermediate size ad-hoc wireless sensor networks exposed to varying temperatures often present in on-site civil engineering measurements.

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“…Due to their mixed advantages in resolution, speed, power, and cost, SAR ADCs are widely applied in industry controlling, medical instruments, auxiliary analogue-to-digital interfaces of microprocessors, and so on [11,12]. In recent years, FPGA with the advantages of design flexibility and adaptability is the current trend for the digital implement [13][14][15]. As shown in Figure 1, the multichannel acquisition system is composed of a single high speed SAR A/D converter, a FPGA module, a flash storage module, a USB controller module, several analogue multiplexers, and signal conditioners.…”

Section: Related Workmentioning

confidence: 99%

An Efficiency Multiplexing Scheme and Improved Sampling Method for Multichannel Data Acquisition System

Chu

Ren

Liu

et al. 2015

International Journal of Distributed Sensor Networks

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The paper proposes an efficient multiplexing scheme that is easy to realize synchronous sampling in a multichannel acquisition system with the large number of analogue inputs and different sampling rates. And then, a simple improved sampling control method is also employed to improve the performance. All the technology of implementing the method is by using a low-cost field programmable gate array (FPGA). A sampling lookup table is built by the rule-based synchronous sampling frame structure for the input analogue multiplexers and stored into the internal block RAM resource in the FPGA to reduce the internal wiring resources and optimize the utilization. The improved sampling method obtains several samples in a sampling period and gets the average value as the final output for the sampling channel. In addition, the standard sine wave FFT test method is implemented to test the dynamic parameters of the acquisition channels. The experiment results show that the dynamic performance of the acquisition system is significantly improved. The proposed multiplexing scheme and sampling method can easily be reconfigured for other applications.

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High Resolution Time-Interval Measurement Systems Applied to Flow Measurement

Cited by 11 publications

References 6 publications

Ultrasonic Flow Measurement with High Resolution

Ultrasonic Flow Measurement with High Resolution

Simultaneity Analysis In A Wireless Sensor Network

An Efficiency Multiplexing Scheme and Improved Sampling Method for Multichannel Data Acquisition System

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