What are the disadvantages optimal household bimetallic strip bottle thermometer?

For a grocery store or treasure the mother has a lot of good a bimetallic thermometer, new mothers in brewing formula, often inexperienced, unable to forecast the powder of thermometer. It is often necessary to an external thermometers for measuring temperature. Common on the market have a mercury thermometer, temperature measurement, a probe thermometer, infrared thermometer, etc. Mercury thermometer: easy to rupture, can cause the mercury in a thermometer plunged into the milk powder, if the children have a mercury ingested milk powder has certain harm on children's physical and mental health, especially when eating 30 ml of great influence. Temperature measuring stick: the principle of two-line hybrids discoloration. Advantage is cheap. Faults are many, with color display, only know about, no specific readings. Temperature measuring stick matter against the bottle, by heat transfer temperature response is slow. Because the bottles are frequently cleaning, disinfection, cleaning temperature measuring stick is easy to fall off after a few times. If the bottle in hot water high temperature sterilization, temperature measuring stick will bring the problem of pollution. Electron probe thermometer: using the principle of thermal resistance, because depend on the battery, long easy battery leakage, and the battery is easily contaminated soil. Infrared thermometer: using the principle of infrared radiation, need to avoid according to the baby's eyes, a small amount of radiation, because is a non-contact thermometer, high precision of more expensive. For bimetallic thermometer is ruled out in ordinary life, using the two kinds of metal heat bilges cold shrink principle to develop and become, compared to other thermometer for mercury-free harm, convenient to carry, no liquid, can be achieved by air, not easy to break even, the advantages of the economical characteristics of friends attention has also been a number of consumers, so the market will now widely used bimetallic thermometer.