An ultrasonic flow meter is a type of a flow meter that measures the velocity of a fluid with ultrasound enabling it to calculate the volume flow. Using ultrasonic transducers, which convert a signal in one form of energy to another form of energy, the flow meter can measure the average velocity along the path of an emitted beam of an ultrasound, by averaging the difference in measured transit time between the pulses of ultrasound propagating into and against the direction of the flow or by measuring the frequency shift from the theory of the Doppler effect, which works the same way as a moving car with a siren.
The Electric Toothbrush makes use of electric power to oscillate the brush head. The electronic parts are absolutely sealed to avoid damage by water. Some of them require replaceable batteries, which may be rechargeable or disposable. This toothbrush is useful for those people who are not efficient at cleaning the teeth. Also, those who have arthri...