scholarly journals A Two-Channel DFT Spectrum Analyzer for Fluctuation Enhanced Sensing Based on a PC Audio Board

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4307
Author(s):  
Emanuele Cardillo ◽  
Graziella Scandurra ◽  
Gino Giusi ◽  
Carmine Ciofi
Keyword(s):  
Low Cost ◽  
Low Frequency ◽  
Spectrum Analyzer ◽  
Frequency Noise ◽  
Frequency Range ◽  
Main Requirement ◽  
Dual Channel ◽  
Input Signals ◽  
Reconstruction Software ◽  
Noise Measurements

The main requirement for using the Fluctuation Enhanced Sensing technique is the ability to perform low-frequency noise measurements. The portability of the measurement system is also a quite desirable feature not limited to this specific application. In this paper, an approach for the realization of a dual channel spectrum analyzer that is capable of exploring frequencies down to DC, although based on a USB sound card, is proposed. The lower frequency range of the input signals, which is outside the frequency range of the sound board, is upconverted to higher frequencies by means of a very simple modulation board. Then, the entire spectrum is reconstructed numerically by proper elaboration. With the exception of the modulation board, the approach we propose does not rely on any specific hardware. Thanks to the efficiency of the spectra estimation and reconstruction software, which is based on a public domain library, the system can be built on a low-cost computer single board computer, such as the Raspberry PI3. Moreover, when equipped with an optical TCP/IP link, it behaves as a compact spectrum analyzer that along with the device under test can be placed into a shielded environment, thus being isolated from external electromagnetic interferences.

RESEARCH AND MAPPING OF LOW FREQUENCY NOISE GENERATED BY POWER PLANTS OF INDUSTRIAL ENTREPRISES

Akustika ◽  
2021 ◽  
pp. 103
Author(s):  
Andrey Vasilyev
Keyword(s):  
Power Plants ◽  
Low Frequency ◽  
Environmental Noise ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Frequency Range ◽  
Noise Mapping ◽  
Industrial Enterprises ◽  
Noise Measurements ◽  
Urban Territory

Environmental noise level from industrial enterprises is constantly increasing, especially in low frequency range. This paper presents the results of research and mapping of low frequency noise generated by power plants of industrial enterprises. Environmental noise mapping results of urban territory of Samara region of Russia are also presented. Results of noise measurements during industrial enterprises operation (on the example of “KuibyshevAzot” company) are showing that in some measuring points there were exceeding values compared with Russian sanitary norms requirements. The most serious problem is low frequency noise impact.

scholarly journals LOW-FREQUENCY NOISE MEASUREMENTS OF IR PHOTODETECTORS WITH VOLTAGE CROSS CORRELATION SYSTEM

Measurement ◽  
2021 ◽  
pp. 109867
Author(s):  
Krzysztof ACHTENBERG ◽  
Janusz MIKOŁAJCZYK ◽  
Carmine CIOFI ◽  
Graziella SCANDURRA ◽  
Krystian MICHALCZEWSKI ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Ir Photodetectors ◽  
Noise Measurements ◽  
Correlation System

Low-Frequency Noise Measurements as a Quality Indicator for Ohmic Contacts to n-GaN

2003 ◽  
Vol 433-436 ◽  
pp. 677-680 ◽  
Author(s):  
Nobuhisa Tanuma ◽  
Hirokazu Tanizaki ◽  
Saburo Yokokura ◽  
T. Matsui ◽  
Sumihisa Hashiguchi ◽  
...  
Keyword(s):  
Quality Indicator ◽  
Ohmic Contacts ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Noise Measurements

scholarly journals Low Frequency Noise Remove from EEG Signal

2020 ◽  
Vol 9 (1) ◽  
pp. 1510-1513
Keyword(s):  
Human Brain ◽  
Random Noise ◽  
Low Frequency ◽  
Frequency Noise ◽  
Eeg Signal ◽  
Low Frequency Noise ◽  
Frequency Range ◽  
Average Value ◽  
Different Types ◽  
The Brain

The electrical activity of the brain recorded by EEG which used to detect different types of diseases and disorders of the human brain. There is contained a large amount of random noise present during EEG recording, such as artifacts and baseline changes. These noises affect the low -frequency range of the EEG signal. These artifacts hiding some valuable information during analyzing of the EEG signal. In this paper we used the FIR filter for removing low -frequency noise(<1Hz) from the EEG signal. The performance is measured by calculating the SNR and the RMSE. We obtained RMSE average value from the test is 0.08 and the SNR value at frequency(<1Hz) is 0.0190.

Sign in / Sign up

Export Citation Format

Share Document