This column is moderated by Béla Lipták, automation and safety consultant and editor of the Instrument and Automation Engineers’ Handbook (IAEH). If you have an automation-related question for this column, write to [email protected].
Question
Best method to detect oil density: Which technology does the oil industry use for inline, oil density measurements?
Francoise Lee
Answer
There are a number of methods. The newest and probably one of the most frequently used nowadays is Coriolis, but you can also use the old-fashioned method of having a slug catcher or other vessel fill to a certain level measured via level switches, then use a DP cell to measure the liquid pressure, which due to the fixed height is equivalent to the density. This is the old-fashioned knock system.
There also are ultrasonic and level sensor applications, so the big issue is to decide where the measurement will be taken, the complexity of the equipment and/or accuracy required.
Alex (Alexandro) Varga
I'm sure there are several analyzers that are specifically designed to provide very detailed oil component analysis. However, if all you need to measure is density, then I suggest a Coriolis meter, which gives you density, temperature and flow in one meter. It is reliable and can be very accurate if the proper manufacturer/model is selected. If the line is large, you can save money by placing a much smaller-sized meter on a small recycle stream.
Hunter Vegas
