Which products are involved?
SRV, SRD, DVM, DVP, SME-TR/TRD.
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To achieve target viscosity driven end-product, Rheonics recommends directly using the sensor reading for quality control. However, our customers do at times use our onboard correlation models to create correlations between lab and SRV or SRD viscosity values. Often this is done to re-use the historical lab data they have collected on their product and to create a overlap during the transition from lab driven quality control to realtime online quality control enabled by Rheonics sensors like SRV and SRD.
Rheonics application engineering team has done studies internally on typical non-Newtonian fluids and published recommendations for creating correlations between lab measurements and real-time inline SRV or SRD viscosity measurements. You can follow the same methodology to establish the correlation. You can also use our application engineering team to advise/help with creating these correlations.
Refer to next pages for
Creating correlations between SRV/SRD and lab rotation instrument - Case study
How to program correlation models on Rheonics sensors? - Article
If you are producing different products, the same correlation may not hold true and you will need to have correlation models for each of those products - these you will have to check to see if you need individual correlation or can stay with universal correlation. For product-based correlations, we advise you implement it on either your PLC where you can select the product you are producing or create a table that shows the SRV/SRD value and the expected lab value - print and hangs it next to the reactors/vessels. That way the operators can see the SRV/SRD value and know that they have reached the previously established lab values. It also means that if they take a sample and send it to the laboratory, they have high level of confidence that the sample will measure correctly in the laboratory. This enables realtime quality checks and allows operators to increase throughput of mixers, grinders, blenders and other reaction vessels.
State of the art viscometer - SRV: Built to support scale-up from pilot to production and from vessel to vessel and plant to plant.
The most common issue with older viscometers that your production would have tried is that they do not scale from pilot to production and need application engineering whenever you want to use the sensor in a new line. This is not the case with SRV/SRD, the main motivation behind developing SRV/SRD was to have a very repeatable and reproducible sensor so when you have an SRV/SRD in one line and want to use another SRV/SRD in the next line (it could be a larger vessel, etc) the sensor measures the same values if the fluid is same.
There are no additional considerations for you to take for scale-ups. The sensor is built to do exactly that. What we recommend is that if you have a non-Newtonian shear-sensitive fluid, you should check the effect of the speed of mixing/flow on the viscosity measurement. This gives you an idea of how to scale the measurements in a production line if it has very different flow/mixing characteristics.
Why is viscosity different between instruments?This is common for non-Newtonian fluids. The viscosity for these fluids depends on multiple factors like shear rate and temperature. Then, a unique viscosity value can't be associated with the fluid. Review more information here:
- Non-Newtonian fluid viscosity measurement with inline viscometer SRV
- The myth of accuracy for inline viscosity measurements