# Analyzing oil content in water

D

#### dasau

Hi
We have an application where the oil in water (Produced water) to be measured to check the guarantee of Produced Water treatment plant. The analyser will be installed upstream of the treatment plant.

My problem is that the oil content is 5% and i am not able to find an analyser which can measure this high level of oil in water content.

Please let me know if particular analyser model can measure 5% oil in water?

If no analyser is available to measure such high oil in water content(5%), I am thinking to install two (2) analyser, one is purely oil in water analyser for the lower range may be 0 ~ 10000ppm (0 ~1%) and second one of water cut analyser which can be used for 0 ~ 5% oil in water content.

The output of second analyser which is watercut analyser should be calibrated to provide % of oil in water.

I need the analyser output in 4~20 mA and available powers are 24VDC/ 230 VAC. Utility available is instrument air.

Regards
Dasau

D

#### dave b.

at that level of oil you might consider a fluid density measurement (corolis effect).

J

#### JMW

At 5% concentration, it is indeed possible to obtain a measure of concentration based on vibrating element density meters. It requires two things to deliver a reasonable result, a knowledge of the density of the raw water and the density of the oil.
"Reasonable" depends on the accuracy needed.

However, is it inaccurate (or lazy) to refer to his as the "coriolis effect".

The coriolis effect is the phase shift that occurs across the ends of a vibrating tube(s) as flow takes place through the tubes. This measurement depends on the tubes being vibrated. Originally this was at some fixed frequency but where the more efficient method of allowing the drive frequency to vary to match the resonant frequency then it is found that the resonant frequency varies with the mass of the system; i.e. the mass of the sensors and the mass of the contained fluid. Mass can vary with the density of the fluid and hence density can be calculated based on resonant frequency.
However, it is not correct to refer to this measurement of density as the "coriolis effect".