Abstract: The invention is directed to a coaxially arranged, off-axis optical system for a sighting device or aiming device. It is the object of the invention to provide a possibility for constructing an optical system in such a way that the typical disadvantage with respect to the tightness of a sighting device in an open-type construction is overcome and a good flattening of the image field is achieved in addition to the high optical imaging quality of the aiming mark. According to the invention, by means of a coaxially arranged, off-axis optical system for a sighting device or aiming device comprising a lens group, wherein the lens facing the target object is constructed as a converging meniscus and the lens facing the eye is constructed as a diverging meniscus, with a dichroic reflector and an embodiment for the aiming mark, the above-stated object is met in that a correction lens with positive refractive power is arranged at a distance of less than 0.

Abstract: An ultrathin-walled multiwell reactor for heat block thermocycling of samples includes an array of small-volume wells of identical height with similarly shaped sample wells formed in a top surface of a heat block. The multiwell plates are preferentially vacuum formed out of a 30-50 micron thick thermoplastic film and can be used for rapid, oil-free temperature cycling of small (1-10 &mgr;l) volume samples.

Abstract: A heat block thermocycler to perform rapid PCR in multiple small-volume samples (1-20 &mgr;l) employing, low profile, low thermal mass sample block the temperature of which can be rapidly and accurately modulated by a single thermoelectric pump (thermoelectric module). An array of spaced-apart sample wells is formed in the top surface of the block. The samples are placed into the wells of ultrathin-walled (20-40 &mgr;m) multiwell plate and located into the sample block. The heated lid tightly seals the individual wells by pressing the sealing film to the top surface of the multiwell plate. Air pressure arising inside the tightly sealed wells at elevated temperatures deforms the elastic walls of the wells of the ultrathin-walled plate and brings them into close thermal contact with the sample block. A gasket thermally isolates the sample block from the heated lid. The PCR reactions (30 cycles) can be performed in 10-30 minutes.

Abstract: Atomizing device for atomic absorption spectroscopy according to the Zeeman method, wherein a tubular atomizing furnace which is transversely heated via wings and with horizontally oriented furnace tube is located with its furnace wings between vertically arranged electrodes for examination of liquid specimens fed from the top and for examination of solid specimens fed from the side, and the vertically oriented atomizing furnace is located laterally between magnetic poles.