High D values are mostly obtained due to a high damping of the oscillating crystal that is normally originated from soft layers which don´t follow the sensor oscillation, producing internal friction caused by deformation; also could be related to loosely bonded molecules [22,26].
The arrival of the seismic wave was detected as the effect of a sensor oscillation of a suspended type magnetometer, which is not used in this paper.
Priming, tempering and transient oscillation of the sensor systems.
Finally, forced oscillations of the sensor diaphragm with residual stress in contact with a liquid are investigated.
In the experiment, an oscillation circuit and the sensor were connected, and the sensor output was measured using a frequency counter (53131A, Hewlett Packard).
This paper presents a ring oscillator with the function of the oscillation controlled for wireless sensor systems (WSSs).
It is also not plausible that the oscillation comes from the sensor oscillation caused by low-frequency seismic waves, such as the Rayleigh or Love waves, because of the much longer period (i.e. about 4 minutes) than that of the Rayleigh or Love waves (i.e., their major period is normally shorter than 30 seconds or at most 1 minute or so e.g. Selby et al., 2005).
The readout method utilizes a semi-digital excitation scheme that lacks a second harmonic, which is the frequency of the driving force, and thus the oscillation frequency of the sensor.
Considering that the quartz crystal resonant (QCR) sensor with the oscillation circuit as a driver will stop oscillation when it encounters a large damping medium.
Thermal fluctuations affect the viscosity and density of the liquid and therefore the oscillation frequency of the sensors.
Tracking system, apparatus stiffness, load oscillation, force transducer, other sensors, and additional measuring devices may be incorporated, integrated and evaluated in an experimental set-up.
