scholarly journals Establishment of 2TP air-dielectric capacitance standard for 1 pF, 10 pF, 100 pF and 1000 pF in the frequency range up to 10 MHz by resonance frequency at NIMT

2021 ◽  
Vol 18 ◽  
pp. 100261
Author(s):  
Monthol Homklintian
Keyword(s):  
Resonance Frequency ◽  
Frequency Range ◽  
Dielectric Capacitance ◽  
Capacitance Standard

Optical Vibration and Acceleration Sensor With a Silicon Cantilever

1999 ◽  
Author(s):  
Mitsuteru Kimura ◽  
Katsuhisa Toshima ◽  
Harunobu Satoh
Keyword(s):  
Simple Model ◽  
Optical Fiber ◽  
Resonance Frequency ◽  
Acceleration Sensor ◽  
Frequency Range ◽  
Silicon Cantilever ◽  
All Optical ◽  
New Type ◽  
Good Agreement ◽  
Optical Vibration

Abstract A new type all optical vibration and acceleration sensor using the combination of micromachined Si cantilever and optical fiber is proposed, and its fundamental characteristics are demonstrated. The light emitted from bulb-lens set into the V-groove is reflected at the reflector formed on the Si cantilever and then recoupled into the bulb-lens. Several sensors with different length (0.64–6.0 mm long) of the Si cantilever are fabricated to compare the theoretical resonance frequency fr obtained from the simple model and experimental ones. They had good agreement. From the sensing principle the sensing frequency range of the vibration is suitable below the fr of the Si cantilever of the sensor.

scholarly journals A Medium-Frequency Fiber Bragg Grating Accelerometer Based on Flexible Hinges

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 6968
Author(s):  
Zichuang Li ◽  
Lei Liang ◽  
Hui Wang ◽  
Shu Dai ◽  
Ke Jiang ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Fiber Bragg Grating ◽  
Temperature Effects ◽  
Bragg Grating ◽  
Structure Model ◽  
Frequency Range ◽  
Medium Frequency ◽  
Acceleration Sensors ◽  
Compensation Function ◽  
Sensing Characteristics

Mediumfrequency fiber Bragg grating (FBG) acceleration sensors are used in important applications in mechanical, aerospace and weapon equipment, and have strict requirements in terms of resonance frequency and sensitivity. A novel medium-frequency accelerometer, based on fiber Bragg grating and flexible hinges, is proposed in this paper. The differential structure doubles the sensitivity of the sensor while avoiding temperature effects. The structure model and principle for the sensor are introduced, the sensor’s sensing characteristics are theoretically analyzed, and the structure parameters for the sensor are determined through numerical analysis. The sensing experiments show that the resonance frequency of the sensor is approximately 2800 Hz, the sensitivity is 21.8 pm/g in the flat frequency range of 50–1000 Hz, and the proposed sensor has a good temperature self-compensation function and lateral anti-interference capability.

Drive of a Piezoelectric Cycloid Motor in a High Frequency Range

1993 ◽  
Vol 5 (5) ◽  
pp. 427-433
Author(s):  
Iwao Hayashi ◽  
◽  
Nobuyuki Iwatsuki ◽  
Koosuke Fujimoto ◽  
◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Rotational Speed ◽  
High Frequency ◽  
Inertial Effect ◽  
Maximum Output ◽  
High Frequency Range ◽  
Frequency Range ◽  
Maximum Torque ◽  
Output Torque ◽  
Improved Characteristics

A piezoelectric cycloid motor was proposed by the authors, and their experiments revealed that the rotational principle was effective and that the motor kept its rotational speed constant up to its maximum output torque. However, the maximum torque was small, and the rotational accuracy was poor. In this report, the motor is driven in a high frequency range including the motor's resonance frequency to obtain improved characteristics. Because the driving amplitude of the stator is increased by resonance, the inertial effect of the stator is expected. As a result, the maximum output torque has been increased to six times, while the rotational accuracy has been much improved.

Subjective Response to Whole-Body Vibration

1982 ◽  
Vol 1 (3) ◽  
pp. 109-122
Author(s):  
Richard W. Shoenberger
Keyword(s):  
Resonance Frequency ◽  
Magnitude Estimation ◽  
Whole Body Vibration ◽  
Alternative Methods ◽  
Whole Body ◽  
Vibration Exposure ◽  
Subjective Response ◽  
Frequency Range ◽  
Body Vibration ◽  
Subjective Intensity

Pioneer studies of subjective response to whole-body vibration were mainly directed toward construction of equal intensity contours, described by such subjective labels as “intolerable,” “alarming,” or “annoying.” In a series of more recent investigations, carried out at AFAMRL, psychophysical measurement and scaling techniques have been adapted for use in whole-body vibration experiments, primarily to evaluate the intensive dimension of various types of vibration environments. A program of research is described in which the methods of magnitude estimation and intensity matching have been used to construct a family of Z-axis equal intensity curves in the whole-body resonance frequency range; investigate subjective response for frequencies below 1 Hz; evaluate alternative methods for assessing the severity of multifrequency and random vibrations; and compare the subjective intensity of vibrations in various translational and angular modes. Results from these experiments have contributed to the expansion and improvement of whole-body vibration exposure criteria.

Direct electron heating experiment on the Aditya tokamak using fast waves in the ion cyclotron resonance frequency range

2011 ◽  
Vol 53 (9) ◽  
pp. 095011 ◽  
Author(s):  
Kishore Mishra ◽  
S V Kulkarni ◽  
D Rathi ◽  
Atul D Varia ◽  
H M Jadav ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Cyclotron Resonance ◽  
Ion Cyclotron Resonance ◽  
Frequency Range ◽  
Electron Heating ◽  
Ion Cyclotron ◽  
Fast Waves

scholarly journals Control the Frequency Response of a Loudspeaker by Changing Its Enclosure

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Pavlo Olehovych Riabokon
Keyword(s):  
Resonant Frequency ◽  
Resonance Frequency ◽  
Frequency Response ◽  
Rock Music ◽  
Low Frequency ◽  
Total Quality ◽  
Frequency Range ◽  
Low Frequencies ◽  
Frequency Components ◽  
Internal Volume

This article analyzes how to control frequency response of a loudspeaker by changing the volume of its closed-box enclosure. The calculation is performed by the method of  Thiele-Small on the basic of a pre-calculated loudspeaker, the parameters of which are given in third section. This became possible because of the simplification of the circuit on figure 1 to the form of circuit on figure 2. This allowed us to consider it as a second order filter (presence of two reactive elements). Obtained results are compared with corresponding characteristics of open-box enclosure of the same loudspeaker, that was pre-calculated by the author too. Results are presented graphically in figure 3 and 4. As can be seen from them, the resonant frequency of the loudspeaker in the closed-box enclosure is higher than the resonant frequency of the loudspeaker in the open box. The result in the form of a ratio  is listed in table 2. Analyzing the obtained data, it can be noticed that with the change of the internal volume of the closed box (and hence its total quality factor), it is possible to affect both the resonance frequency and the peak amplitude values in these frequencies by changing the FR. The result shown in figure 3 and 4 is achieved by taking into account effect of radiation only on the one side of the driver (in the case of open-box enclosure). Closed box was calculating by taking into account both sides radiation of the driver. Shifting the resonance frequency of the system towards higher frequencies and increasing the sound pressure on the resonance generally worsens the FR of the loudspeaker (reduces the reproduction of low-frequency components of sound and increases the unevenness of the frequency). However, certain variants of this group of frequency characteristics may be useful depending on the reproducible frequency range and need of emphasize the low-frequency components (for example, in rock music). If you need a smoothed low-frequency sound, it is appropriate to use systems with low overall quality and increased internal volume or open-box enclosure. Therefore, the volume of the closed-box enclosure significantly affects the resonant frequency and the shape of the frequency response of the loudspeaker. Reducing the volume of the enclosure of the loudspeaker leads to a decrease in its frequency range due to low frequencies and at the same time increase in the unevenness of the frequency response. The change in the resonant frequency of the system as the volume of the closed-box enclosure decreases, the less the volume of the closed-box.

Vibratory crusher forced oscillations in resonance frequency range

2015 ◽  
pp. 42-45 ◽  
Author(s):  
E. V. Shishkin ◽  
◽  
S. V. Kazakov ◽  
Keyword(s):  
Resonance Frequency ◽  
Forced Oscillations ◽  
Frequency Range
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