Thermometers made of mercury-in-glass Advantages of mercury thermometers: Mercury thermometers provide reliable readings. Because metal is an excellent heat conductor, it reacts quickly to temperature changes. The saturation vapor pressure of mercury is quite low. This means that mercury will not evaporate at normal temperatures. This also means that there will be no risk of poisoning someone by inhaling mercury vapors.
Disadvantages of mercury thermometers: Mercury is toxic. Even small amounts of mercury can cause serious health problems if it is ingested or absorbed through the skin. Any material that contains mercury should be handled properly to prevent it from being released into the air. Otherwise, you may be exposed to this danger.
How do mercury thermometers work? A thermometer with a mercury bulb operates on the same principle as a typical dial thermometer. But instead of a needle pointing to different degrees on a face, there is a glass tube filled with mercury. As the mercury in the bulb heats up, it expands and pushes against the side of the glass container, making the needle move.
These days, most thermometers are electric. They work by using sensors that detect body heat or cold and measure its intensity. These sensors then communicate with an alarm or device over Bluetooth or Wi-Fi connections so that you are notified when it's time to check your child's temperature.
The benefits of these thermometers are their low cost, ease of reading, ability to be submerged in liquids, low maintenance requirements, and dependability. The downsides are that they are easily broken, and if the glass tube breaks, there is a risk of mercury poisoning. Also, they tend to be less accurate at higher temperatures.
Clinical thermometers can be divided into two categories: electronic and mechanical. Electronic clinical thermometers use sensors such as resistors or thermistors to measure body temperature. They are more expensive than mechanical clinical thermometers but have many advantages over them. They can measure temperature up to about 105 degrees F (41 degrees C), while mechanical thermometers can only measure up to about 100 degrees F (38 degrees C). Electronic clinical thermometers can also measure temperature more accurately than mechanical thermometers because they don't suffer from tolerance errors like mechanical thermometers do. Mechanical clinical thermometers consist of a handle with a bulb attached to it by a stem. When you hold the handle, the bulb presses against your skin to measure your temperature. These thermometers are very cheap and easy to use; all you need is a hand-held device for taking measurements. However, they cannot be used for measuring temperatures above about 105 degrees F (41 degrees C) because the metal stem would become too hot to touch.
Mechanical clinical thermometers work on the same principle as a regular bathroom thermometer.
Mercury is the finest choice for liquid-filled thermometers because to its strong thermal conductivity, great sensitivity to temperature, and superb visibility. Alcohol thermometers may readily leak and get wet on the wall, resulting in less accurate and slower readings. Thermometers that use other liquids may not be as accurate or have other limitations.
The advantages of mercury thermometers are their great accuracy and wide measuring range, from 0 to 500 degrees Celsius (32 to 930 degrees Fahrenheit). Disadvantages include toxicity of mercury and need for periodic replacement of contaminated liquid inside the device. Devices that use other liquids can also have accuracy issues due to impurities in these other liquids.
Thermometers made with mercury are very sensitive to external vibrations, so they should be kept out of the reach of children. Vibrations from typing or machine tools can cause inaccurate readings. Mercury-based thermometers are destroyed by light; if exposed to sunlight, they will release toxic vapors into the air.
People who work with mercury should take special precautions to prevent exposure to this toxic substance. Employees should not handle thermometers without protective gloves, boots, and equipment. Contaminated clothing can be washed at home using a washing machine set at 40 degrees C (104 degrees F) or hotter. Do not burn or melt mercury-containing products.