Fluid flow devices fall into a number of device categories as well as fluid classes. In general we can split the fluids into two classes; gasses and liquids. Within these two broad classes are a number of special classes that one should be careful of. Flammable liquids and gasses require special handling, as do those that are at temperature extremes (cold or hot).
When selecting a transducer you should be cautious that the device you are selecting is compatible with the fluid and conditions you hare working with. A few examples would be acids, food grade liquids, and DI water. Surprisingly de-ionized water is an extremely harsh liquid that can cause serious headaches.
The physical measurement devices come in a number of classifications. While the following classifications do not match any industry standards, they serve to break the transducers down into some reasonably functional groups.
These are:
- Obstruction flow meters
- Velocity flow meters – Including Moving Member meters
- Positive Displacement meters
- Variable area meters Electronic meters
We will spend some time at each category, looking at the particular devices that fall into that category. Some of these devices will work with a wide array of fluids, while others have significant limitations. This tutorial should help you understand what these restrictions are and when to use or not use a particular meter.
Credits - Mitchell Cottrell