DocumentCode :
864272
Title :
The design and analysis of an improved high air flow meter with analog/digital filters
Author :
Wu, Yue ; Bobis, James P. ; Gehman, Richard
Author_Institution :
Sun´´s Eng. Inc., Elk Grove Village, IL, USA
Volume :
41
Issue :
6
fYear :
1992
fDate :
12/1/1992 12:00:00 AM
Firstpage :
791
Lastpage :
796
Abstract :
High-air-flow meters in the range of 0.0 SLM (standard liters per minute) to 200.0 SLM, which use a built-in microbridge sensor in flow housing, induce a significant amount of turbulence noise in the output signal. The sensor output signal is analyzed, and an analog/digital design is introduced to reduce the noise and to realize the industrial standard output range of 1.00 VDC to 5.00 VDC. Tests were performed with an A/D data acquisition system and Fourier analyzer for flow data analysis. The flow data file was used for offline time- and frequency-domain analysis and digital filter design simulation. The magnitude, mean, and autocorrelation of the noise induced on the output signal were calculated and measured. An analog Butterworth filter implemented on this high-flow meter in real time showed increased SNR, overshoot of 10%, and the response time of 400 ms. The digital forward linear predictor was implemented with TMS320C25 digital signal processor (DSP). Noise was reduced, overshoot was zero, and the response time was 195 ms
Keywords :
Fourier analysis; analogue-digital conversion; data acquisition; flow measurement; flowmeters; signal processing equipment; 195 ms; A/D data acquisition; Fourier analyzer; Si; TMS320C25 digital signal processor; air flow meter; analog Butterworth filter; analog/digital design; analog/digital filters; analysis; autocorrelation; bridge sensor; design; design simulation; digital forward linear predictor; flow data analysis; frequency-domain analysis; industrial standard; magnitude; mean; noise; real time; time domain analysis; Data acquisition; Data analysis; Delay; Frequency domain analysis; Noise reduction; Performance analysis; Performance evaluation; Signal analysis; Signal design; System testing;
fLanguage :
English
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9456
Type :
jour
DOI :
10.1109/19.199409
Filename :
199409
Link To Document :
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