Measuring [NaOH] in a working vacuum evaporator.
Measuring [NaOH] in a working vacuum evaporator.
(OP)
How can the concentration of NaOH, in water solution, be measured while the solution is in a vacuum evaporator? The goal is to take the concentration to say 28% to cause the precipitation of a crystalline material.
My list of potentials include pH, Conductivity, Density and Viscosity.
I also suspect it might be beneficial to remove a stream of the solution and filter the precipitate on a "continual" basis, as there will be approximately 10% solids when the endpoint is reached. If the stream is removed, the concentration measurement might be simplified.
I would appreciate any comments.
My list of potentials include pH, Conductivity, Density and Viscosity.
I also suspect it might be beneficial to remove a stream of the solution and filter the precipitate on a "continual" basis, as there will be approximately 10% solids when the endpoint is reached. If the stream is removed, the concentration measurement might be simplified.
I would appreciate any comments.





RE: Measuring [NaOH] in a working vacuum evaporator.
RE: Measuring [NaOH] in a working vacuum evaporator.
I agree with your comment of simple and robust. Those features are very important.
RE: Measuring [NaOH] in a working vacuum evaporator.
K-Patents sells a process refractometer for density measurement in adqueous solution (optical refractive Index).