Analytical Method
Continuous optical measurement of liquid refractive index enables real-time concentration tracking of dissolved solids in industrial chemical baths. In continuous textile finishing and dyeing, online refractometry monitors chemical bath concentration inside the pad trough without manual sample extraction. Inline optical sensors transmit instant concentration data to central process controllers.
Refractive Principle
Critical angle measurement of light passing through liquid media determines solute concentration according to Snell’s law. Utilizing online refractometry allows dyers to track alkali or salt concentrations in pad liquors continuously during long production runs. Automatic temperature compensation corrects refractive index drift caused by thermal fluctuations in the dye bath.
Process Monitoring
Concentration shifts occur when incoming damp fabric dilutes pad liquor or when bath components deplete at unequal rates. Deploying online refractometry triggers automatic dosing pumps to replenish depleted chemicals before shade deviation occurs. Optical prisms require automated wash cycles using water jets to clear chemical buildup or lint deposits.
Realtime chemical tracking reduces fabric shade variation across multi-thousand-meter production lots.
Measurement Boundary
Refractometric readings measure total dissolved solids rather than distinguishing between individual chemical species in a complex mixture. Applying online refractometry works best in single-solute solutions or fixed-ratio chemical blends where refractive index correlates directly with total bath strength.
