In the 19th century in England James Dyyuar Devar has invented capacity for storage of the rarefied gases. After a while his pupil Reynold Burger has found commercial realization for its invention. Very quickly its firm became world renowned. This company began to release nothing but thermoses.
And the modern thermos does not differ from its invention. The thermos represents glass or metal flask in the body.
If the thermos is necessary for country trips, then it is better to choose with metal flask as it is stronger. If use in the city is provided, then it is necessary to choose thermos with glass flask as it is more hygienic. At the same time they keep temperature equally.
Experts consider that thermoses keep temperature in plasticity also as metal. The good thermos holds temperature about 50 degrees even in 24 hours. These criteria are answered by thermoses of Thermos, Hangzhou EXCO, Penguin, Mimi Mimi , etc. Upon purchase of thermos make sure, the stopper is screwed up densely. Generally preservation of the necessary temperature depends on it. Also preservation of temperature depends on volume. The more engine capacity, the better remains heat. Upon purchase of thermos surely open it. If you feel unpleasant smell, this thermos means it is made of low-quality materials. If you have decided to choose thermos, such quality because of the price or design, - do not do it as it emits toxic agents in liquid. If you buy glass thermos, shake it. The flask should not dangle, otherwise it just by all means will break sooner or later. The metal flask, of course, stronger, but also it at strong deformation can receive microcracks therefore the vacuum will disappear and thermal insulation and tightness will be lost. According to experts - various tea leaves and tinctures need to be cooked in glass thermos. The quality of thermos can be checked. It is necessary to fill in in it boiled water and to leave for 10 minutes. If the body has heated up, then the thermos rejected. Modern thermoses are intended not only for liquid, but also for food and are issued in the form of saucepans. Conclusions:
- the more engine capacity, the better remains temperature.
- the metal flask more reliable and is more durable than glass, but in turn glass than gigiyenichny.
- when filling boiled water the body in 10 minutes should not heat up.