Even if you do not love hunting and fishing and in general not really often get out to the nature, all the same in your house there has to be thermos as it can be necessary also under other circumstances. Food and tea in thermos can be taken in the road, to the dacha, for work. Even at home you can be necessary to maintain temperature of the prepared dish or the made broth within several hours. It is essential facilitate your life in such situations the good thermos can. It is necessary to define its quality at home right after purchase.
1. Begin determination of quality of thermos even in the course of acquisition. Pay attention to cover and stopper. They have to be very hermetic. Through stopper about 40% of heat are lost. The design of stopper and the button, the less heat is simpler they will release outside.
2. Turn off cover and smell thermos. The good thermos will not have any pungent and specific smells.
3. Shake thermos a little. If you feel that something dangles inside, it is sign that the flask is badly attached to the body and can become useless quickly at the slightest blow, in particular, if flask glass. In qualitative thermos nothing has to dangle.
4. Read instructions. The reliable, respecting themselves and the consumer producers, surely provide the detailed description of properties of thermos and give certain guarantee for quality of vacuum in thermos.
5. Before buying thermos, decide on the requirements by the time of heat preservation. According to it choose thermos volume. Even very good thermos of 0.5 liters will not be able to keep heat within 24 hours. The more the volume, the longer thermos holds heat.
6. Having come home, at once begin quality test of vacuum as in shop visually it cannot be made. Gather boiled water in flask and pour out it in 5 minutes. So you will warm up thermos. Then again pour in thermos boiled water, but not to the very top, leave 1 cm for air (so do always when filling thermos). Leave thermos for 30 minutes. If after this time of wall of thermos become warm, the thermos rejected. Return it to shop.
7. Check thermos for compliance to the stated parameters. Time of heat preservation depends on quality of vacuum, i.e. distance between flask and the body. The it is less, the thermos contents cool down quicker. It is possible to check it, filling in thermos boiled water and having left it for 24 hours at the room temperature. After 24 hours check water temperature in thermos. If liquid temperature in 1.5-2 liter thermos has not fallen lower than 55 degrees, then the thermos well keeps heat.