When it comes to flow meter accuracy, regardless of the type or manufacturer of flow meter used in a system, there are two key aspects of flow meter that must be considered.
First, the equipment’s actual stated accuracy range, which will be given as a percentage figure like +/- 0.2%. This would suggest that the device has an accuracy range of 0.4%; however, in order to achieve this in practical operational circumstances, every other aspect of the system would have to perform at its absolute best.
After taking into consideration other elements like the accuracy ranges of external sensors and the flow profile of the pipes used to transport the fluid, there is one more important concept to consider: the rangeability of the flow meter. This is the parameter range of fluid velocity within which the flow meter can measure fluid velocity to its fullest capacity.
The difference between the highest and lowest flow rates that the equipment can measure to its claimed accuracy level is known as the turndown ratio, and is frequently used in measurement applications. The achievable accuracy of the equipment rapidly diminishes once the flow rate either exceeds or falls below this range. Therefore, it is essential to consider the anticipated system dynamics when selecting a flow meter that will serve its purpose.