| 摘要 |
The invention concerns a handy laboratory apparatus by which samples can be heated or cooled according to choice. As a thermal energy source a block of one or more Peltier elements (5) is used, which, by inversing the direction of the alimentation current, can be switched to cooling or heating mode. One of the thermal poles of the Peltier elements contacts a metal block (1), whereas the opposite pole is in contact with a heat exchanger (8). The metal block which comprises an essentially horizontal working surface (2) is separated from the heat exchanger by an insulating layer (9); the outer surfaces of the metal block (1) are protected from any heat exchange with the environment by the insulating layer (10). The vessels containing the samples to be heated or cooled are placed onto the working surface (2)or else can be inserted into further metal blocks which serve as working modules with suitable cavities for the sample vessels and a flat ground face, which are placed or screwed onto the metal block (1). The apparatus comprises three separate parts. the heating and cooling device, the modules receiving the sample vessels and the electric alimentation and control unit, the latter provided with a pulsed mains adapter for the alimentation of the Peltier elements and an electronic control circuit, which, by choice, can be connected to a microcomputer for programming temperature cycles. The apparatus is suited for work in the biological, biochemical or genetic laboratory, where cycles have to be accomplished with temperatures partly above and partly below room temperature. It is however transportable for work outside the laboratory as well, e.g. in mobile units such as cars, railways and airplanes.
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