Ultrasonic Flow Meter Working Principle Pdf

The ultrasonic signals are generated by piezo electric crystals applying a voltage.

Ultrasonic flow meter working principle pdf.

An ultrasonic flow meter is a type of flow meter that measures the velocity of a fluid with ultrasound to calculate volume flow. The famous hc sr04 ultrasonic sensor generates ultrasonic waves at 40khz frequency. Ultrasonic flow meters operate using the transit time differential method. The sound wave propagation speed in the downstream direction will increase and the backward direction will decrease.

Ultrasonic flow meters measure the difference of the transit time of ultrasonic pulses propagating in a flowing fluid. The canoe moving with the flow needs much less time to reach the opposite bank. Conversely the piezo electric crystal creates a. The ultrasonic doppler flow meters are commonly used in dirty applications such as wastewater and other dirty fluids and slurries which ordinarily cause damage to conventional sensors.

Principle of magnetic flow meter based on faraday s law. An ultrasonic sensor can convert electrical energy into acoustic waves and vice versa. Clamp on ultrasonic flow meter working principle. Using ultrasonic transducers the flow meter can measure the average velocity along the path of an emitted beam of ultrasound by averaging the difference in measured transit time between the pulses of ultrasound propagating into and against the direction of the flow.

Magnetic flow meters works based on faraday s law of electromagnetic induction. Each sensor alternately can transmit and receive ultrasonic signals. The acoustic wave signal is an ultrasonic wave traveling at a frequency above 18khz. According to this principle when a conductive medium passes through a magnetic field b a voltage e is generated which is proportional to the velocity v of the medium the density of the magnetic field and the length of the conductor.

Clamp on ultrasonic flow meter adopts the measurement principle of time difference method. The ultrasonic sensor or transducer works on the same principles as a radar system. This time difference is a measure for the average velocity of the fluid along the path of the ultrasonic beam. Simultaneously the transit time of these signals are measured.

Prepared by william e. Ceesi measurement services garner iowa this paper is aimed at ultrasonic natural gas meters that use transit time across the gas pipe as the measurement variable. Imagine two canoes crossing a river on the same diagonal line one with the flow and the other against the flow. Fundamental principles of clamp on ultrasonic flow meters overview of selection installation operation and maintenance of clamp on meters.

It uses the ultrasonic wave emitted by the sensor to propagate in the flowing fluid. The transit time differential measurement is based on a simple physical fact.