摘要 |
A method and a device for activating an indicator which comprises two liquid-filled ampoules (19, 20) separated by a rupturable partition (21) are disclosed. The method is characterised by exerting a compressive force for breaking the partition (21) and mixing the liquid in the ampoules by moving pressure-exerting means, preferably rolls (10-15), in a path relative to the indicator, alternatingly along the central portion of the indicator and along the edge portions of the indicator. Preferably the exertion of pressure on the central and edge portions of the indicator is repeated at least once. The device comprises pressure-exerting means (10-15) which are movable relative to the indicator in a path passing the indicator. Each pressure-exerting means (10-15) has a width smaller than the extent of the indicator transversely of the path of the pressure-exerting means relative to the indicator. A first pressure-exerting means (10) is arranged to pass in its path the central portion of the indicator. A second and a third pressure-exerting means (10, 12) are arranged to pass in their paths the edge portions of the indicator. Preferably the pressure-exerting means (10-15) are rolls, and it is particularly preferred that all rolls are arranged on a common axis (16), and that all rolls constitute an integrated cylindrical unit (9), the individual rolls being formed of ridges (10, 15) of the cylinder (9). |