Precipitation on pH sensors caused by contaminants impacts sensor measurements, which has consequences for process consistency. A buildup of contaminants also effects sensor lifetime.
This case study looks at how a leading pigment company improved product consistency and dramatically increased pH sensor lifetime by switching to intelligent sensors and a sophisticated cleaning regime.
In the production of titanium dioxide, the chemical and photochemical performance properties of the pigment mainly depend on particle size and the chemical composition on the particles’ surface. Achieving the desired surface on particles involves a treatment process in which the particles are coated with various inorganic compounds in a reactor.
Precipitation of these coating compounds is controlled through carefully adjusting the reactor pH.
However, certain compounds not only precipitate on the TiO2 particles, precipitation on pH sensors occurs too. This impacts sensor response time and measurement accuracy, leading to process inconsistency.
By switching to a pH sensor designed to tolerate slurries and high particle-load media, the pigment company has found measurements remain accurate for much longer. However, as precipitation on pH sensors cannot be avoided, regular sensor cleaning is also necessary. Use of a retractable housing enables sensor cleaning and exchange without process interruption.