Plastics. Determination of the tendency of compounds and products based on vinyl chloride homopolymers and copolymers to evolve hydrogen chloride and any other acidic products at elevated temperatures. Potentiometric method|Plastics and rubber technology, Plastics, Polyvinyl chloride, Vinyl resins, Polymers, Thermal stability, Thermal testing, Gas analysis, Hydrogen chloride, Potentiometric methods, Chemical analysis and testing, Specimen preparation, Thermal properties of materials, Testing conditions, Reproducibility, Test equipment, Calibration