Sonomicrometry
Sonometrics Sonometrics
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작성자 Vasocare 조회Search : 1,207Hits DateDate : 2020-09-25 16:10:20본문
Sonomicrometry for Animal Test
Basic Principles of Sonomicrometry
Sonomicrometry
is the measurement of distances using sound. Transducers (commonly called
"crystals") made from piezo-electric ceramic material transmit and
receive sound energy. Typically, these transducers operate at ultra-sound
frequencies (1 Mhz and higher). To perform a single distance measurement, one
crystal will transmit a burst of ultrasound, and a second crystal will receive
this ultrasound signal. A digital sonomicrometer has the added benefit of
transmitting from a single crystal to multiple receivers and thus render
multiple distances per "ping" As an additional functional step a
digital sonomicrometer can switch crystal modes from transmitter to receiver.
The elapsed time from transmission to reception is a direct and linear representation
of the physical separation of the crystals.
Any sonomicrometer is therefore a timing device, repeating this measurement of
transit-time hundreds or thousands of times per second. The Sonometrics Digital
Sonomicrometer measures this transit time in discrete time steps similar to the
operation of a digital stopwatch. The resulting transit time is easily
converted to a distance if the speed of sound in the material being measured is
known. Typically, in biological materials, this speed is 1540 meters per
second, or 1.54 mm per microsecond. Transit time is measured digitally,
typically in steps of 15 nano-seconds, resulting in a resolution of 0.024 mm
(24 μm). Option resolution enhancements of 0.012 mm (12.4 μm) are also
available.
Considering the idea of a single crystal transmitting to a single receiver, one
distance can be determined. A crystal can transmit to several other crystals,
then one of those "receiver" crystals can change to a transmitter and
ping back.
This additional functional of the digital sonomicrometer will yield more
available measurements. A four crystal instrument will yield 12 distance
segment, when more crystal are used the segment count goes up exponentially (32
crystals give 496 unique segment lengths).
The resolution of any sonomicrometer depends on its ability to accurately
detect the received ultrasound signal and on its ability to measure transit
time. Advanced high-gain, low noise circuitry in the Sonometrics Digital
Sonomicrometer allows for the detection of the received ultrasound signal at a
constant phase-angle for precise tracking of the received signal regardless of
it's frequency. This allows for complete independence of crystal frequency and
measurement resolution.
Manufacturer’s Website: http://www.sonometrics.com/index.html