Ultrasonic Flowmeters

Ultrasonic Flowmeters:

Already we have seen some of the ultrasonic devices before like Ultrasonic Level Sensor and Ultrasonic Distance Sensing. Now, I am going to explain one more ultrasonic device here. Ultrasonic Flow-meters are used to detect the speed of flow or subsequently quantity passed through the flow in given time.

Types of Ultrasonic Flowmeter:

1. Transit Time Type.
2. Doppler Frequency Shift Type.

1. Transit Time Type Ultrasonic Flowmeters:

In this type, two sensors are mounted on the pipe or channel. They send and receive the ultrasonic pulses simultaneously. When the speed of flow is zero or flow is steady, both the sensors receive the reflected pulses at the same time. Vice versa, when the fluid is in motion, sensors receive the pulse with delay between them. This delay is called as transit time difference. This transit time difference is directly proportional to velocity of flow and hence the volume of flow per unit time.

2. Doppler Frequency Shift Method:

Doppler effect could be explained as the frequencies of received sound waves depends on the motion of the source or observer relative to the propagating medium. The transmitter transmits ultrasonic waves. These are reflected from particles and bubbles. Frequency shifting takes place in reflected wave which is linearly proportional to the rate of flow of materials.

Advantages:

1. The flow of pure water, wash water, sewage, process liquids, oils, and other light homogeneous liquids can be measured.
2. It have no moving parts and hence have very less or no maintenance.
3. Can be used for variety of pipes.
4. It have flexibility to be used on existing pipelines.
5. It can be used as a portable device.
6. It does not have any contact with liquid and hence no danger from corrosive liquids.

Seminar on Ultrasonic Flow meter:

Above is given the information about ultrasonic flow meters. Here are short framework for seminar on ultrasonic flowmeter.

1. Introduction to Ultrasonics.
2. Ultrasonics Properties.
3. Ultrasonic Flowmeter.
4. Construction and working.
5. Types.
6. Transit time type.
7. Doppler Frequency Shift Method.
8. Advantages.
9. Limitations.
10. Applications.