This sounds more complex since the variation in the aqueous phase sg means you cnanot use the density measurement to determine the ratio. This would also aply to the gamma ray device.
On the plus side the fact that this is a well homogenised fluid flow and isn't really two phase i.e. the components are not separated into discrete phases,rather the opposite given the static mixer, means that any form of density meter will return a true density for the homogenised fluid.
The problem therefore is to determine the s.g. of the aqueous phase i.e. the sodium sulphate solution.
Is there a point in the system where the sodium sulphate solution is seperate from the combined flow?
If so then a density meter can be used to determine the density of the sodium sulphate solution and use this as a live input to a density meter in the combined flow stream.
The main stream density meter software will then use the base density of the oily component and the live input of sodium sulphate density with the measured base density of the combined flow stream to determine the ratio of oily to aqueous.
Absent a seperate sodium sulphate fluid flow, things get complex as it is important to pin down an sg value for this component by some other means.
Perhaps a conductivity measurement or pH will reveal the sodium sulphate content of the combined stream but whether this would reveal anything about its composition in the aqueous phase is moot.
That is, will a conductivity measurement relate to the concentration of the sulphate in water or in the combined flow stream? If the latter we are struggling, if the former then we can develop a relationship with the SG of the aqueous stream and thus use this as an input to our density meter software for the determination of the ratio. (can't comment on if your mass meter has suitable software or if it measures density with sufficient accuracy in which case a separate dedicated density meter will be required).
JMW
