Alveograph. A dough-testing instrument, formerly known as the Chopin Extensigraph after its developer, that is designed to measure the extensibility (q.v.) and resistance to expansion (q.v.) of a thin sheet of dough (q.v.). In its operation, a small thin dough disc is subjected to constant air pressure in such manner as to form a bubble that expands until it bursts. A recording manometer (q.v.) charts the air pressure within the bubble against time on a graph. The resultant curves provide indications of the dough's tensile strength or stability, its extensibility, and of the flour's protein strength. The instrument is widely used in European milling and baking laboratories.