Ultrasonic Clamp On Flow Meter

About Ultrasonic Clamp On Flow Meter

Ultrasonic Clamp On Flow Meter utilizes two transducers that function as both ultrasonic transmitters and receivers. The transducers are clamped on the outside of a closed pipe at a distance from each other. The transducers can be mounted in V method in which case the ultrasound transverses the pipe twice, or W method in which case the ultrasound transverses the pipe four times, or in Z method in which case the transducer are mounted on opposite sides of the pipe and the ultrasound transverses the pipe only once. The selection of mounting method depends on pipe and liquid characteristics. When flow meter works, two transducers transmit and receive the ultrasonic signal which travels firstly downstream and then travels upstream. Because ultra sound travels faster downstream than upstream, there will be a difference of time of flight (delta t). When the flow is still, the time difference (delta t) is zero. Therefore, as long as we know the time of flight both downstream and upstream, we can work out the time difference and the flow velocity (V) and flow v (Q) the follow-ing formula.

Application:

• Raw Water, cooling water, DM water, hot water, chemicals, HVAC energy measurement system, beverages, food, pharmaceutical, power plants etc

Advantages:

No moving parts

Sensor clamp outside the pipe, no need to cut the lines

Disadvantages:

• Oil or corroded pipes may impede acoustic signal
• Too much aeration or turbulence can destroy signal

Transmitter and receivers roles are constantly switched by electronics. Ultrasonic pulses travelling in the direction of the flow, travel path between transducer in a shorter period of time than pulses travelling against the flow. This is because the flow speeds up pulses travelling downstream but slows down pulses travelling upstream.

Where:

• V: Liquid velocity
• K: Constant
• D: Distance between the two transducers
• Dt: Difference in time of flight