As a specialist liquid flow meter manufacturer, Titan first began developing a viable, accurate ultrasonic non-invasive small bore measuring device in 2001 as part of a long-term strategic plan. The work resulted in patented ultrasonic technology which has since led to an expanding line of ultrasonic flowmeters and patents ranging from signal processing methodology to novel mechanical design.
Titan’s ultrasonic flow sensors use high frequency sound waves to measure flow using the time-of-flight principle within the liquid in a small pipe. The ultrasound is injected with the direction of flow into the liquid by one piezoelectric crystal (the sensor) and is received by a second piezoelectric crystal further down the tube. These crystals then reverse the direction of the ultrasound in the tube and both time-of-flight acoustic signals are measured. As one sound pulse is accelerated by the velocity of the liquid and the second retarded, the difference in the flight time is twice the fluid velocity, and as the dimensions of the flowmeter tubes are known the volumetric flow can be calculated.
Widening the operational window
Most ultrasonic flowmeters can reliably measure fluids that transmit ultrasonic sound waves within a band (e.g. ±30%) around the speed of sound in water at 20°C. But if a fluid has significantly differing acoustic characteristics, for instance viscous organic fluids or if measurement is at elevated temperatures, then the acoustic operational window can be missed by the sensors. Titan’s proprietary Interface Software offered on the Atrato® and MetraFlow® overcomes this application challenge. The software functionality allows you to view the Acoustic signal of the measured fluid in real time and if required, move its position in the measurement window to ensure reliable flow measurement in the conditions of operation. This increases the versatility of a single fluid calibrated meter to a much wider range of applications.
Ultrasonic flowmeters are the ideal solution for measuring low flow rates. Titan has developed several generations of ultrasonic low flow meters based upon their patented time-of-flight design able to measure the velocity of the fluid within the pipe. The very high signal to noise ratio from these devices has been widely proven to enable metering of extremely low flows with great precision. The Atrato® line of patented ultrasonic inline flowmeters consists of four models operating over a flow range of 2ml per minute up to 20 litres per minute. These low flow ultrasonic flow sensors also offer excellent turndown (> 200:1), repeatability (to ±0.1%), linearity and accuracy of better than ±1.0% of reading.
Titan’s ultrasonic flow devices are independent of Reynolds numbers and can therefore operate from laminar flow through to turbulent flow. This makes them highly commercial being able to accurately measure liquids ranging from water to high viscosity oils. Being through-flow devices, they can also be tolerant to impurities in the system which would cause havoc to meters with moving parts.
The rugged, clean bore construction of the Atrato® and MetraFlow® ultrasonic flowmeters make these devices ideal for almost any low flow application, from research and development to industrial processes, and even metering of chemically challenging liquids. In addition, the Process Atrato®, durably constructed from 316 stainless steel and PEEK specifically designed for use in demanding process and control environments is available.
