When we think of “thermometer” we often imagine this small transparent glass tube containing a liquid, often red or silver; well this thermometer that you imagine is a thermometer with mercury. Real professional temperature measuring tool. He quickly took up residence in our private bathrooms to take family members' temperatures and check fevers. This mechanical thermometer has long been used as a medical thermometer for measuring patients' body temperatures before being completely withdrawn from the market. How does the thermometer with mercury ? Why has it disappeared from medical practices? What mercury-free thermometers have become good alternatives? Our temperature taking experts come back with you on all these questions to help you see more clearly.
The thermometer with mercury 🧪
At first glance, you might think that you need choose between the thermometer with mercury and the thermometer without mercury, like the red pill and the blue pill in the movie Matrix. Nay! Let us tell you more about the mercury thermometer. Especially its removal from the market for body temperature measuring instruments…
The history of the thermometer with mercury
The thermometer with mercury was created in 1724 by the German physicist Gabriel Fahrenheit. As a tip, it has a glass bulb. It is itself topped with a long glass tube graduated in degrees Fahrenheit or degrees Celsius a few years later (depending on the country). The bulb then contains mercury, a liquid metal at room temperature whose coefficient of thermal expansion happens to be high. When mercury heats up thanks to the temperature of a body, it expands quickly and its volume increases in the glass tube, until it gives a precise measurement via the graduation.
The dangers of mercury thermometers
Mercury is part of what we call, along with calcium and lead for example, heavy metals. These are highly toxic metals that can cause damage to human health. Beyond the dangers of local traumatic lesions (perforations, etc.) and skin wounds that could cause the breakage of the ampoule when taking a temperature. The biggest indirect risks come from mercury vapors.
And a thermometer with mercury is broken, the vapors are immediately inhaled by the occupants of the room, which could especially happen in a hospital environment. It was then imperative to be extra vigilant in the rooms where children live (the most vulnerable to this neurotoxicant) and in patients' rooms, that is to say in closed, poorly ventilated, heated environments.
The gradual elimination of the thermometer with mercury
In France, the sale of thermometers with mercury therefore ended thanks to the decree of December 24, 1998 and was quickly reinforced by a ministerial circular also prohibiting the use of these mercury medical thermometers in French hospitals from September 1999. Our European neighbors banned the sale of mercury thermometers on July 10, 2007.
Mercury-free thermometers 📲
Of course, today there are different alternatives to these medical thermometers ; underarm or rectal thermometers, the non-ear contact thermometer ideal for taking babies' temperatures and other infrared temperature sensors whose measurement ranges are perfect for taking body temperatures.
The axillary thermometer
The most obvious with its stainless steel tip and which strongly resembles our mercury thermometer, is the one called the axillary thermometer to take the temperature rectally or under the armpit. Its digital screen directly displays the precise temperature thanks to the internal temperature measuring probe.
The infrared thermometer
Forehead thermometer or ear thermometer, these non-contact medical electronic thermometers are reliable and precise measuring devices. Infrared/laser thermometer technology offers you comfort and ease of use. No need to clean it, change the tip, insert the probe, etc. They also allow measurement of the ambient temperature. In addition, they are particularly fast and display the exact temperature in a few seconds on their LCD screen.
The different types of thermometers
There are therefore numerous alternatives to the mercury thermometer. However, if your needs go beyond what these mercury-free thermometers can provide, do not hesitate to continue your research on the different types of thermometers existing:
- The electronic/digital thermometer
- The mechanical thermometer
- The IR/laser thermometer
- The gallium thermometer
- The thermometer with probe
- Galileo's thermometer
- The multifunctional thermometer
- Thermometer vs. anemometer
- Thermometer vs logger
- Thermometer vs hygrometer
- Thermometer vs pH meter
- Thermometer vs thermocouple
- Thermometer vs Thermostat
