Abstract: A system and a method for the production of polycrystalline silicon according to the monosilane process are disclosed. At least one reactor (10), at least one converter (20), at least one injection tank (30) and at least one vaporizer (40) are provided. Each reactor (10) is provided with an inlet pipe (11a) for fresh mixtures of gases and an outlet pipe (11b) for partially used-up mixtures of gases. Likewise, each converter (20) comprises an outlet pipe (21) for a mixture of gases and each vaporizer (40) comprises an outlet pipe (41) for a mixture of gases. Several sampling elements (7) for specimens to be measured are provided in the inlet pipe (11a) and the outlet pipe (11b) of each reactor (10) as well as in the outlet pipe (21) of each converter (20) and the outlet pipe (41) of each vaporizer (40). The withdrawn specimens to be measured are fed by the sampling elements (7) via a pipe (8) to at least one gas-phase chromatograph (2).

Abstract: An apparatus and a system for extracting gaseous specimens to be measured, preferably during the production of polycrystalline silicon, are disclosed. The apparatus according to the invention is a flange-like device (80), which is placed between each of the at least two pipe sections (11a, 11b, 21a, 21b, 41a, 41b) of the outlet pipes (11, 21, 41).