| 摘要 |
In the closure for sample bottles which is known per se and consists of a pierceable, circular-disc-shaped septum (3), which rests on the edge of the bottle neck, and of a metal cap (6) which holds said septum and has a beaded edge, a pressure plate (4) with a central opening (5) is arranged between the septum and the metal cap, said pressure plate having at least one straight edge which runs along the chord of a circular segment of the surrounding circle around the pressure plate. Each segment, not covered by the pressure plate, of the circular-disc-shaped septum made of elastic material acts under overpressure in the sample bottle like the flap of a non-return valve; it bends upwards until the overpressure has dropped below a threshold value which can be predetermined with the elasticity of the septum. The closure is used in sample bottles for analytical series investigations, in particular in gas chromatography, where the samples are heated to temperatures above 100 DEG C and overpressures can arise due to faulty operation. <IMAGE>
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