Electronic microscopes are used today not only by scientists, - the device is demanded by numismatists, philatelists, jewelers, amateur radio technicians. This modern device rather difficult and expensive; therefore upon purchase it is necessary to pay attention to types of a product.
Issue and reflective electronic microscopes
Issue devices are the most widespread. They are used when it is required to study more or less large object. In an issue microscope the image turns out thanks to electrons which are let out by the studied object. Obtaining the qualitative image requires more intensive radiation therefore an object is placed in powerful electric field. Other way of increase in intensity of radiation - heating of a subject of researches to high temperature. Rather reliable device can sustain similar conditions. Reflective microscopes by the principle of work remind issue, a difference only in a way of radiation. Both these types of microscopes will hardly be suitable for "house" researches.
Raster and mirror electronic microscopes
The raster type of devices is the generator of an electronic beam. Operating it, it is possible to read out information from a surface of the studied object. Here, in fact, the beam plays a scanner role: when studying a subject comes to an end, you obtain full information on its structure. If you need to investigate the object which does not have pronounced magnetic or electric field, then the mirror electronic microscope best of all will approach. He also forms a beam and carries out scanning of a surface. The difference from the raster device is that the beam is not mobile, - i.e. available to study will be only the site near a beam. As a result not the really qualitative image which can be improved by means of use of the amplifier of light turns out.
Vikhrevy electronic microscope
It is one of the last developments of scientists, - to buy today the similar device not easy. A novelty essence – in formation of the rotating electronic beam which in work begins to remind a whirlwind, a tornado. In a design of the device the screen covered with sodium nitride is used. It provides easy access of electrons (absorption does not happen), which, shifting phases, turn into a whirlwind. As a result the power of a beam increases if to compare to other types of electronic microscopes.
Electronic microscopes of USB
These are modern devices which can be connected to the computer in house conditions. Such microscopes best of all are suitable for amateur researches. Buying such device, pay attention to several main technical characteristics. It: - permission; - frequency rate; - food type; - features of illumination. The permission parameter belongs to the camera. By the way, in the majority of devices of this type it can be used as the ordinary webcam. If you are not going to study microorganisms, then there is enough frequency rate 400. When choosing concrete model try to refuse purchase of cheap Chinese devices, - as a rule, the operational characteristics stated in passports do not correspond to valid.