Zero flow offset measurement

Jon Lawson

Morgan Advanced Materials has made significant advances in minimising zero flow offset, to levels as low as 60ps. By streamlining the transducer design and production methods, this has been shown to restrict variation to less than 5% over a wide range of environmental conditions. Put simply, the lower the variation, the more accurate the meter reading.

In industrial and domestic ultrasonic flow measurement applications accuracy in measuring flow rates in dynamic flow conditions is essential. Given that customers are charged on the basis of their meter readings, the reading needs to accurately reflect the quantity of material used, be this gas or water.

Measuring the 'time of flight' between the upstream and downstream transducers, and then reversing the process gives two figures which, together, provide a measurement of the flow rate of liquids and gases. However, even where there is no flow in the tube, there is typically a minimal discrepancy between the two. This phenomenon, known as ‘zero flow offset’, is a by-product of the physical constraints of materials and signal processing technologies that may impact on the accuracy of meters. Advancements made by Morgan’s team of sensor specialists have gone a long way towards addressing this.