Stainless steel is generally chosen because of balanced overall performance. First, listen to the sound, put your ears close to the mouth of the pot, and hear the whining sound inside, which means it has a heat preservation function. The heat preservation pot can keep warm mainly by the vacuum isolation layer, which can effectively prevent the transmission of physical radiation. The sound cannot be used in a vacuum. The principle of propagation inside, when blowing inward, it reflects sound waves, the louder the sound, the better the vacuum.
Secondly, check whether the surface of the inner tank and outer casing is uniformly polished, whether there are bruises and flaws, the smoothness of the mouth welding, and the quality of the plastic parts, the inner cover should be made of food-grade PP material, and the tightness and screw plug Whether it matches with the body of the kettle closely. Whether it is leaking or not, the airtightness of a thermos is of course not comparable to that of a thermos, as long as it does not leak immediately after being knocked over, it will pass. Look at the weight of the pot and press the shell hard. If it deforms, it means that it is thinner and limited in quality. It is not that the heavier the better. Some bad manufacturers add cement to the bottom of the pot to make it shoddy.
Check the thermal insulation performance, which is an important indicator of the stainless steel thermal insulation pot. Quick test: It can be checked by hand feeling after it is filled with hot water. The lower part of the cup body will heat up after a few minutes after filling the hot water in the non-insulated pot, indicating that the insulation is poor, and the lower part of the insulated pot is always unchanged. It is normal for the mouth to get fever. This means that the inner tank and the outer shell are not in contact with other places except the spout, and the heat preservation performance is good. Long-term test: Pour boiling water at 80% of the capacity of the pot and see how long it takes to cool down.