The correct answer is: B. Sonic
A sonic digitizer is a type of digitizer that measures a wave traveling at the speed of sound. It is used to measure the speed of sound in a medium, such as air or water. Sonic digitizers are used in a variety of applications, including medical imaging, industrial process control, and environmental monitoring.
A sonic digitizer works by emitting a sound wave and then measuring the time it takes for the wave to travel to a sensor and back. The speed of sound is then calculated by dividing the distance between the emitter and the sensor by the time it takes for the wave to travel.
Sonic digitizers are available in a variety of sizes and shapes. They can be handheld or mounted on a tripod. Some sonic digitizers are designed to be used in harsh environments, such as those with high levels of humidity or dust.
Sonic digitizers are a valuable tool for measuring the speed of sound in a variety of applications. They are accurate, reliable, and easy to use.
The other options are incorrect because:
- Electrostatic digitizers measure the electrical charge on a surface.
- Digitizing spheres are used to measure the distance between two points.
- Capacitive digitizers measure the capacitance between two plates.
- None of the above options measure a wave traveling at the speed of sound.