Coulometric Karl Fischer

Moisture Quantification

Polymers such as polyamide or polycarbonate require strict water control during injection moulding to prevent hydrolytic degradation. Excess moisture trapped in the resin matrix causes chain scission, which lowers the molecular weight and destroys mechanical properties of the finished part. Coulombic measurements provide a datasheet value that allows processors to verify the efficiency of desiccant dryers or vacuum ovens before production begins.

Accurate readings ensure that the resin remains within the manufacturer specification, preventing defects like silver streaking or bubbles in transparent lenses.

Electrode Sensitivity

Electrolytic current monitors the progression of the reaction until the chemical equivalence point is reached. A small excess of iodine triggers a potential change in the detector electrodes, which halts the current and signals the end of the titration cycle. High precision instruments manage this threshold with extreme consistency, preventing drift during the measurement of low parts per million concentrations.

Operators verify these sensors by injecting known standards to confirm the accuracy of the total charge summation.

Economic Impact

Virgin material costs often depend on the verified dryness of the product supplied to the moulder. Regrind material absorbs atmospheric humidity faster than its virgin counterpart, necessitating more frequent testing to determine the appropriate residence time in the dryer. Production costs escalate when moisture levels remain unknown, as premature failure of components often occurs after long periods of environmental exposure.

Quantitative control over water concentration provides the primary defense against internal voids and surface finish failures that necessitate expensive scrap cycles.