How does a mercury thermometer work? Mercury thermometer. Effect of mercury on humans
In our time, when digital and electronic technologies are actively developing and are entering all spheres of human activity, playing an increasingly important role and becoming more and more indispensable for each of us, there are ordinary objects and things from our everyday use that will serve us for a long time and be useful.
Such items include the well-known “ thermometer", or as it is more correct to call it - mercury medical thermometer.
Even after the appearance of a large number of models of electronic thermometers, the mercury thermometer has not lost its popularity and is the most common device for measuring the temperature of the human body.
The main element of a mercury thermometer is a capillary tube. The tube is sealed on both sides and the air is pumped out of the inside of it. At one end of the tube there is a reservoir of mercury. There is a special scale for measuring temperature. The scale is marked on a bar attached to the tube. The measurement range of the scale is from 34 to 42 degrees Celsius. For precise measurement body temperature, each degree on the scale consists of 10 divisions equal to 0.1 degrees Celsius.
The fundamental difference between a medical thermometer and conventional mercury thermometers for measuring temperature environment, the junction of the reservoir with mercury and the capillary tube is specially curved and slightly narrowed, which in turn makes it difficult for the mercury to move in the opposite direction.
Thanks to this design of the “thermometer”, when measuring the temperature of a person’s body, mercury heats up, expands and slowly reaches its maximum level, showing the correct temperature.
But at the same time, after stopping the temperature measurement and influencing the thermometer, the mercury does not change its position and the reading on the scale is fixed at the maximum value that was achieved during the measurement. That is why the medical thermometer is called maximum.
To return the thermometer to its initial position in order to further application and measuring temperature, you need to shake the “thermometer”, thereby returning the mercury back to the reservoir.
Advantages of a mercury thermometer:
- A mercury medical thermometer, due to its characteristics, is the most accurate in its performance and is close in readings to a gas thermometer, which is considered a reference thermometer. Therefore, a mercury thermometer measures the temperature of the human body more accurately than other thermometers.
- At the same time, a mercury thermometer is less susceptible than others to the influence of extraneous factors and temperature measurement conditions.
- The design of the mercury “thermometer” allows its disinfection with complete immersion in a disinfectant solution, therefore it is suitable for healthcare and medical institutions.
- Compared to electronic thermometers, a regular “thermometer” is very attractive for its price to any buyer (the cost of a medical mercury thermometer is 25-50 rubles). But here it should be taken into account next feature. Mercury thermometer quite difficult to produce. Requires mercury high quality And special cleaning. Requires special equipment for environmentally friendly cleaner production. Therefore, mercury thermometers are being produced less and less, and electronic thermometers are being produced more and more. And with the subsequent development of technology, electronic thermometers will become much cheaper over time.
- The most primitive design of the thermometer ensures simplicity and accessibility of use.
Disadvantages of a mercury thermometer:
- It takes a long time to measure body temperature. On average, temperature measurement should last at least 5-6 minutes, and the most accurate measurement requires 10 minutes.
- But the main disadvantage of a mercury thermometer is the mercury itself. It is the presence of mercury (about 2 grams) – dangerous substance for human health, and glass structure A “thermometer” that easily breaks negates all the advantages of a mercury thermometer compared to all others.
Mercury is a liquid with a silver-metallic sheen that begins to evaporate at temperatures of +18°C and above.
Mercury is a metal silver-white color. But the metal is unusual, in our traditional understanding. The melting point of mercury is very low for metals and is equal to -38.9 degrees Celsius.
Due to this specific property, under normal conditions, e.g. room temperature, mercury is a readily mobile liquid, which, when struck lightly, separates into small balls, and when combined, easily reunites into a single ball.
Another property of mercury is that it begins to evaporate already at a temperature of +18°C and above.
If it crashes in a room or apartment mercury thermometer, then the mercury after impact breaks into many small drops and spreads throughout the room. At the same time, mercury can easily penetrate into the pile of carpets, into cracks in floors, and into the cracks between the baseboard and the floor. Then mercury, actively evaporating, pollutes and poisons all available air in the room.
If a person breathes this air constantly, over time, mercury begins to accumulate in the body, which in turn leads to chronic mercury intoxication, which can manifest itself as a metallic taste in the mouth, headaches, diarrhea, kidney damage, stomatitis, salivation, anemia, dermatitis, tremors limbs.
How to use a mercury thermometer correctly?
Before each measurement of body temperature, it is necessary to check the thermometer by carefully inspecting it. If the mercury reading exceeds 35 C, shake off the thermometer.
Shaking the thermometer is done as follows:
- Take top part thermometer into your fist so that the head of the thermometer rests securely in your palm, the reservoir of mercury points down, and the middle of the thermometer is between your thumb and forefinger
- Several times, with a jerky movement at the elbow joint, forcefully lower your hand down, while making a sharp stop of the hand, so that the “thermometer” actually shakes.
- After measuring the temperature, the mercury thermometer must be disinfected, but do not wash the mercury thermometer under any circumstances. hot water. From exposure hot water it may lose its accuracy or even deteriorate or even crack.
Before eliminating the consequences of a broken mercury thermometer, you need to prepare:
- A glass jar with a tight-fitting lid for preserving collected mercury.
- Medical cotton wool, pieces of plaster, sheet thick paper, and rags.
- Large plastic bags for disposal of items that may be contaminated with mercury.
- Knitting needle or thick needle, medical syringe.
- A flashlight or table lamp with an extension cord for lighting.
- Rubber gloves.
- Chemicals that have oxidizing (bleaching or disinfecting) properties and containing chlorine compounds (bleach, chlorinol, etc.). A solution of potassium permanganate may be useful from the first aid kit.
The first stage of mercury removal is demercurization.
Demercurization is the collection of droplets of mercury. This is the most important and time-consuming stage.
Never use a vacuum cleaner to remove dust. There are two main reasons for this.
Firstly, the vacuum cleaner itself will become contaminated with mercury particles, and it will be impossible and dangerous to use it in the future.
Secondly, vacuum cleaner filters will not retain all the mercury, and most already in a sprayed form it will again appear in the room and settle on everyone possible surfaces(from which it will be difficult to collect it), and in large quantities will enter your lungs.
- Remove all people not involved in cleaning from the room. Be sure to remove children and pets from the apartment. Keeping children and animals in a contaminated room is dangerous to their health, and they can spread mercury throughout the room or even ingest it.
- First of all, conduct a thorough inspection of all objects, surfaces and items that may have received droplets of mercury. It is worth considering that elastic mercury balls roll very well on any surface, and can be very small in size.
- It is better to use a flashlight prepared in advance to illuminate all corners, crevices, cracks in the floor, recesses and irregularities. Due to its metallic luster, mercury is easier to see in bright light.
- All items susceptible to mercury contamination must be collected and placed in plastic bags and taken to the fresh air from a contaminated area.
- Upon examination horizontal surfaces and floors, especially parquet or laminate, it is necessary to mark in advance with chalk or pencil the places where mercury particles were found. Avoid stepping on these contaminated areas to avoid getting mercury on your shoes.
- The collection of mercury must begin with the largest drops so that they do not break into smaller droplets. To make it easier to clean up mercury, it is best to use a thick sheet of paper, folded in half, or in the shape of a scoop. To roll drops of mercury onto a sheet of paper, use a thick needle or knitting needle.
- By carefully bringing the drops closer to each other, you can combine several small drops into one large one. Carefully place large drops into the prepared glass jar.
- To collect very small drops of mercury, use a small piece of plaster or adhesive tape. Small drops of mercury should be retained by the sticky side of the patch. Place the patch with drops of mercury stuck to it in a glass jar.
- Drops of mercury can be removed from cracks in the floor, parquet or other objects using a needle with a cotton swab wrapped around it. To be effective, the tampon should be soaked in a solution of potassium permanganate. Place the tampon with drops of mercury stuck to it in a glass jar.
- Drops of mercury can also be removed from the cracks using a medical syringe with a thick needle.
- If you suspect that mercury particles have gotten behind the baseboard, under the laminate or under the parquet floorboard, they should be removed and carefully inspected.
- Collection of mercury particles from broken thermometer may take you several hours. For the safety of your health and to avoid mercury vapor poisoning, every 10-15 minutes you should take a break and go out into the fresh air.
Once you have collected all the mercury, it should be handled very carefully and with care. Close the jar of mercury with a tight lid to prevent mercury vapor from escaping. Under no circumstances should you throw mercury into the trash, garbage chute, or toilet. This will only lead to new, very difficult to remove pollution. A jar of collected mercury can be temporarily placed on a balcony or in a garage, providing all means for its integrity, and then handed over to representatives of the rescue service.
The second stage of mercury removal is chemical demercurization.
It is necessary to proceed to the stage of chemical demercurization only if all visible droplets of mercury have been removed and all objects and things susceptible to contamination have been collected and removed from the room.
To do this, you will need chemicals available at home. Most accessible remedy, which can be found in any first aid kit, is potassium permanganate. Depending on the area of the surface to be treated, we prepare a solution of potassium permanganate. To be on the safe side, it is better to prepare one liter at once.
- To prepare the solution, pour water into a jar and add a few crystals of potassium permanganate to obtain an almost opaque dark brown solution. Based on the proportion per liter of water, add and dissolve a tablespoon table salt, as well as a tablespoon of vinegar essence or a pinch of citric acid. Mix the resulting solution carefully and thoroughly so that no particles remain.
- We put on rubber gloves and begin to treat the contaminated surface with the resulting solution. When treating surfaces, special attention should be paid to cracks, crevices and corners where mercury particles could remain. You can even pour a little solution into such places for more reliable treatment.
- After applying the solution to the surface, leave it for 7-8 hours. As the solution dries, it is necessary to periodically moisten the treated surface with clean water.
- After time has passed, the treated surface is thoroughly washed using detergents and cleaning agents. chemicals. After which you need to do a high-quality wet cleaning throughout the entire apartment.
- To prevent the consequences of a broken thermometer, daily wet cleaning apartments and frequent long-term ventilation.
- Usually, within a week of high-quality cleaning and ventilation, it is possible to completely get rid of mercury particles in the apartment.
What to do after eliminating the consequences:
- After collecting mercury, you must contact the Ministry of Emergency Situations for help by calling 101 to transfer them a jar of mercury.
- Drink as much liquid as possible (water, tea, coffee, juices), since mercury formations are eliminated from the human body through the kidneys.
- If you suspect that mercury is still present in your apartment, call specialists with a mercury gas analyzer. For measurements, please contact the regional centers of hygiene and epidemiology.
What not to do:
- Do not throw a broken thermometer or mercury particles into the trash or into the garbage chute. Two grams of mercury contained in a thermometer is enough to pollute six thousand cubic meters of ambient air.
- Do not flush mercury down the drain. It tends to settle in sewer pipes, and it is almost impossible to extract mercury from the sewer.
- You cannot collect mercury using a vacuum cleaner. A vacuum cleaner, blowing air with mercury, will evaporate the liquid metal, thereby polluting the surrounding air in the room. In this case, you will have to throw away the vacuum cleaner, as it will be dangerous to use.
- Do not sweep up mercury particles with a broom. The hard rods of the broom will only crush the poisonous balls of mercury into fine mercury dust, which will immediately enter your lungs.
- You cannot wash things, clothes and shoes that have come into contact with mercury, either by hand or using a washing machine. It's better to throw these things away altogether.
Maybe it's time to get rid of the mercury in the house?
The fact that mercury thermometers are dangerous has been recognized in the EU and in a number of other countries. That is why the use of mercury thermometers is prohibited in medical and healthcare institutions. Sales are prohibited measuring instruments containing mercury, including thermometers and thermometers. This measure can significantly reduce the amount of toxic mercury entering the environment with household waste.
Electronic thermometers - best alternative mercury thermometers. Since there is no mercury or glass in their body, they are absolutely safe to use for humans, including when measuring in the mouth. And the speed of measurement and the presence of memory distinguishes them favorably from the old mercury thermometer./p>
A thermometer is a device designed to measure the temperature of a liquid, gaseous or solid medium. The inventor of the first device for measuring temperature is Galileo Galilei. Device name with Greek language translates as “to measure heat.” Galileo's first prototype was significantly different from modern ones. The device appeared in a more familiar form more than 200 years later, when the Swedish physicist Celsius began studying this issue. He developed a system for measuring temperature by dividing the thermometer into a scale from 0 to 100. In honor of the physicist, temperature levels are measured in degrees Celsius.
Varieties based on operating principle
Although more than 400 years have passed since the invention of the first thermometers, these devices are still being improved. In this regard, new devices are appearing based on previously unused operating principles.
Nowadays there are 7 types of thermometers:
- Liquid.
- Gas.
- Mechanical.
- Electrical.
- Thermoelectric.
- Fiber optic.
- Infrared.
Liquid
Thermometers are among the very first instruments. They work on the principle that liquids expand when temperature changes. When a liquid heats up, it expands, and when it cools, it contracts. The device itself consists of a very thin glass flask filled with a liquid substance. The flask is applied to a vertical scale made in the form of a ruler. The temperature of the medium being measured is equal to the division on the scale indicated by the liquid level in the flask. These devices are very accurate. Their error is rarely more than 0.1 degrees. IN various designs liquid instruments are capable of measuring temperatures up to +600 degrees. Their disadvantage is that if dropped, the flask may break.
Gas
They work exactly the same as liquid ones, only their flasks are filled with inert gas. Due to the fact that gas is used as a filler, the measuring range increases. Such a thermometer can show maximum temperatures ranging from +271 to +1000 degrees. These instruments are usually used to take temperature readings of various hot substances.
Mechanical
The thermometer works on the principle of deformation of a metal spiral. Such devices are equipped with an arrow. They look a little like a clock. Similar devices are used on car dashboards and various special equipment. The main advantage of mechanical thermometers is their durability. They are not afraid of shaking or shocks, like glass models.
Electrical
The devices operate on the physical principle of changing the resistance level of the conductor when different temperatures. The hotter the metal, the higher its resistance to the transmission of electric current. The sensitivity range of electric thermometers depends on the metal used as a conductor. For copper it ranges from -50 to +180 degrees. More expensive platinum models can indicate temperatures from -200 to +750 degrees. Such devices are used as temperature sensors in production and laboratories.
Thermoelectric
The thermometer has 2 conductors in its design that measure temperature according to the physical principle, the so-called Seebeck effect. Such devices have a wide measurement range from -100 to +2500 degrees. The accuracy of thermoelectric devices is about 0.01 degrees. They can be found in industrial production when measurement is required high temperatures over 1000 degrees.
Fiber Optic
Made from fiber optics. These are very sensitive sensors that can measure temperatures up to +400 degrees. Moreover, their error does not exceed 0.1 degrees. This thermometer is based on a stretched optical fiber, which stretches or contracts when the temperature changes. A beam of light passing through it is refracted, which is recorded by an optical sensor that compares the refraction with the ambient temperature.
Infrared
The thermometer, or pyrometer, is one of the most recent inventions. They have an upper measurement range from +100 to +3000 degrees. Unlike previous types of thermometers, they take readings without direct contact with the substance being measured. The device sends an infrared beam to the surface being measured and displays its temperature on a small screen. However, the accuracy may differ by several degrees. Such devices are used to measure the heating level of metal workpieces that are located in the furnace, engine housing, etc. Infrared thermometers can show the temperature of an open flame. Similar devices are used in dozens of different areas.
Varieties by purpose
Thermometers can be classified into several groups:
- Medical.
- Household for air.
- Kitchen.
- Industrial.
Medical thermometer
Medical thermometers are usually called thermometers. They have a low measuring range. This is due to the fact that the body temperature of a living person cannot be below +29.5 and above +42 degrees.
Depending on the design, medical thermometers are:
- Glass.
- Digital.
- Pacifier.
- Button.
- Infrared ear.
- Infrared frontal.
Glass Thermometers were the first to be used for medical purposes. These devices are universal. Usually their flasks are filled with alcohol. Previously, mercury was used for such purposes. Such devices have one big drawback, namely the need for a long wait to display real body temperature. For axillary execution, the waiting time is at least 5 minutes.
Digital Thermometers have a small screen on which body temperature is displayed. They are able to show accurate data 30-60 seconds after the start of measurement. When the thermometer reaches the final temperature, it creates a sound signal, after which it can be removed. These devices may operate with errors if they do not fit very tightly to the body. There are cheap models of electronic thermometers that take readings no less long than glass thermometers. However, they do not create a sound signal about the end of the measurement.
Thermometers nipples made especially for small children. The device is a pacifier that is inserted into the baby's mouth. Typically, such models emit a musical signal after completing the measurement. The accuracy of the devices is 0.1 degrees. If the baby begins to breathe through his mouth or cry, the deviation from the actual temperature can be significant. The measurement duration is 3-5 minutes.
Thermometers buttons They are also used for children under three years of age. The shape of such devices resembles a pushpin, which is placed rectally. These devices take readings quickly, but have low accuracy.
Infrared ear The thermometer reads the temperature from the eardrum. Such a device is capable of taking measurements in just 2-4 seconds. It also comes with a digital display and runs on . This device is illuminated to facilitate insertion into the ear canal. The devices are suitable for measuring temperature in children over 3 years of age and adults, since infants have too thin ear canals into which the tip of the thermometer does not fit.
Infrared frontal thermometers are simply applied to the forehead. They work on the same principle as ear ones. One of the advantages of such devices is that they can operate without contact at a distance of 2.5 cm from the skin. Thus, with their help you can measure the child’s body temperature without waking him up. The speed of operation of forehead thermometers is several seconds.
Household for air
Household thermometers are used to measure air temperature outdoors or indoors. They are usually made in glass and filled with alcohol or mercury. Typically, their measurement range in outdoor settings is from -50 to +50 degrees, and in indoor settings from 0 to +50 degrees. Such devices can often be found in the form of interior decorations or refrigerator magnets.
Kitchen
Kitchen thermometers are designed to measure the temperature of various dishes and ingredients. They can be mechanical, electrical or fluid. They are used in cases where it is necessary to strictly control the temperature of the recipe, for example, when preparing caramel. Typically, such devices come complete with a sealed tube for storage.
Industrial
Industrial thermometers are designed to measure temperature in various systems. They are usually mechanical type instruments with a pointer. They can be seen in water and gas supply lines. Industrial models There are electrical, infrared, mechanical, etc. They have the widest variety of shapes, sizes and measurement ranges.
Often when repair work or during experiments you have to measure the temperature of the medium by immersing a measuring device in it. For such measurements, a liquid thermometer is required.
Dive point
This mark allows you to compensate for changes in air temperature, which directly affect the liquid.
Liquid thermometers are widely used in factories and factories to take temperature readings. liquid solutions and substances flowing through process pipes. Such procedures make it difficult to measure fluid temperature due to insufficient access. Special measuring channels are created in tubes and reservoirs for inserting the device and taking readings.
Directions for use and precautions
Thermometers consist primarily of glass and liquid. They pose a danger for two reasons: broken glass and the toxicity of the active substance.
Mercury is a very toxic substance
In the chemical industry, mercury or alcohol thermometers are more often used. Laboratory experiments require high precision, and liquid devices allow you to perform procedures on top level. A large volume of mercury is used for this. When working with such devices, a special tray should be kept under the thermometer so that in case of destruction, the mercury can be collected as quickly as possible.
The main thing in case of a broken thermometer is to quickly collect the mercury
Falling from a height of human height, mercury quickly splits into many balls and scatters in all directions. Balls of toxic liquid metal fall into the cracks of the floor, into all holes and cracks.
Mercury is a very fluid metal. Collect it completely - not an easy task. Gradually, the mercury will begin to evaporate, creating a dangerous toxic background. It is not easy to ventilate a room from mercury vapor, since mercury vapor is a very heavy gas.
The procedure for removing mercury from a room is called demercurization.
All work must be stopped immediately, and the mercury must be removed immediately. Removing mercury means the following:
- All visible mercury should be removed immediately. There are two cleaning methods - with a rubber bulb and with a cotton swab. When cleaning with a tampon, remember that the tampon should be lubricated with oil.
- All collected mercury must be transferred to a special service. Mercury should not be poured down the drain; it is much heavier than water.
- The area where the mercury was spilled should be treated with a 20% solution of iron (III) chloride, and then wait until it dries completely.
- After a day, the surface should be wiped detergent and clean water.
Pros and cons of liquid thermometers
The main disadvantages of the devices are the unsafety of liquids in case of depressurization (especially in the case of toxic mercury) and the impossibility of use in extremely low or high temperatures.
The division price of most thermometers is 1-2 degrees Celsius. This allows calculations to be made quite accurately, but each model has its own temperature range.
The advantages of liquid thermometers are a wide range of applications - both in household and medical purposes, and air, steam, gas and power plants.
Popular models of liquid thermometers, their prices and comparison
The most popular devices include TTZh-M isp4, SP-1, BT-52.220 and TS-7-M1 isp1.
Popular liquid devices: TTZh-M isp4, SP-1, BT-52.220 and TS-7-M1 isp1
TTZh-M isp4
The thermometer is produced by the Steklopribor company. The L-shape allows for readings to be taken in various boiling devices with a valve provided. Average price devices – 350 rubles.
The active substance is kerosene, the scale division is 2 degrees. The length of the immersion part is 6.5 cm, the measured range is from 0 to +100 degrees Celsius.
TS-7-M1 isp1
The device belongs to the budget class - the price varies from 250 to 300 rubles. Mainly used in agriculture. The working fluid is methylcarbitol, the measured temperature limit is from -20 to +70 degrees Celsius. The length of the immersed part is only a few centimeters.
BT-52.220
Bimetallic device, Designed specifically for aggressive environments found in oil, food and chemical industries.
Resistant to corrosion, allows changing temperature ranges. The average price is 1200 rubles.
Thanks to interchangeable sleeves, the length of the immersion part can vary from 6.4 to 25 cm. The minimum range is from -45 to 0 degrees Celsius. Maximum – from 0 to +450 degrees.
The device was developed by Rosma. The sleeves of this device are made of brass and stainless steel. The device operates at ambient temperatures ranging from -10 to +60 degrees. The dial is made of aluminum. The device is equipped with a radial scale and arrow.
SP-1
The liquid device is produced by the Termopribor company. The average price is about 2000 rubles.
The device operates only in positive ranges. The design allows the use of four ranges: minimum - from 0 to +100 degrees Celsius, maximum - from 0 to +300 degrees.
The device is vibration-resistant and is used in workshops and machine-building factories. Working fluid- mercury.
A thermometer is a special device designed to measure the current temperature of a specific medium upon contact with it.
Depending on the type and design, it allows you to determine temperature regime air, human body, soil, water and so on.
Modern thermometers are divided into several types. The gradation of devices depending on the scope of application looks like this:
- household;
- technical;
- research;
- meteorological and others.
There are also thermometers:
- mechanical;
- liquid;
- electronic;
- thermoelectric;
- infrared;
- gas.
Each of these devices has its own design, differs in operating principle and scope of application.
Operating principle
Liquid thermometer
At the core liquid thermometer lies the effect known as the expansion of liquid media when heated. Most often, such devices use alcohol or mercury. Although the latter is systematically abandoned due to the increased toxicity of this substance. And yet, this process so it is not completely completed, since mercury provides better measurement accuracy, expanding according to the linear principle.
In meteorology, instruments filled with alcohol are often used. This is explained by the properties of mercury: at temperatures of +38 degrees and above, it begins to thicken. In turn, alcohol thermometers allow you to evaluate the temperature regime of a specific environment heated to 600 degrees. The measurement error does not exceed a fraction of one degree.
Mechanical thermometer
Mechanical thermometers are bimetallic or delatometric (rod, rod). The operating principle of such devices is based on the ability of metal bodies to expand when heated. They are highly reliable and accurate. The production cost of mechanical thermometers is relatively low.
These devices are used mainly in specific equipment: alarms, automatic temperature control systems.
Gas thermometer
The operating principle of the thermometer is based on the same properties as the devices described above. Except that in this case an inert gas is used. In fact, such a thermometer is an analogue of a pressure gauge, which is used to measure pressure. Gas appliances used for measuring high and low temperature environments (range is -271 - +1000 degrees). They provide relatively low accuracy, which is why they are abandoned for laboratory measurements.
Electronic thermometer
It is also called a resistance thermometer. The principle of operation of this device is based on changing the properties of a semiconductor built into the design of the device when the temperature increases or decreases. The dependence of both indicators is linear. That is, as the temperature increases, the resistance of the semiconductor increases, and vice versa. The level of the latter directly depends on the type of metal used in the manufacture of the device: platinum “works” at -200 - +750 degrees, copper at -50 - +180 degrees. Electric thermometers are rarely used, since it is very difficult to calibrate the scale during production.
Infrared thermometer
Also known as a pyrometer. It is a non-contact device. The pyrometer operates with temperatures from -100 to +1000 degrees. Its operating principle is based on measuring the absolute value of energy that a specific object emits. The maximum range at which a thermometer is capable of assessing temperature indicators depends on its optical resolution, the type of aiming device and other parameters. Pyrometers are characterized by increased safety and measurement accuracy.
Thermoelectric thermometer
The operation of a thermoelectric thermometer is based on the Seebeck effect, through which the potential difference is estimated when two semiconductors come into contact, resulting in the formation electric current. The temperature measurement range is -100 - +2000 degrees.
Mercury thermometer (thermometer)- This is the most common and popular means for measuring human body temperature.
Relevance
Not so long ago, this device was the only reliable way to measure body temperature. In a modern high-tech society, this procedure can be carried out using various devices and thermometers. Each of them has both advantages and disadvantages.
Components of a mercury thermometer
The basis of a mercury thermometer is a tube sealed on both sides. Attached to one side is a small container containing 2 grams of mercury. The thermometer has a scale on which the temperature is determined in degrees Celsius (from 34 to 42). The design of the medical thermometer is made in such a way that when the mercury heats up and expands while measuring body temperature, it slowly reaches its value and no longer changes its position. This occurs due to a special curvature and narrowing of the place where the container with mercury is attached to the tube. Therefore, in order to use the thermometer again, it must be shaken off so that the mercury returns to the reservoir. Taking the thermometer in your hands, you need to check what value the mercury column has stopped at and, if necessary, reset this indicator to 35 degrees, gently shake the thermometer
Effects of mercury on the human body
The mercury contained in this thermometer is a silver-white metal that has a liquid structure and also has the property of evaporating at temperatures above 18 degrees. Even with a small impact, a ball of mercury is divided into many small parts and scatters in different directions. If you accidentally break a thermometer, mercury spills onto the floor, splitting into many balls and spreading to large area premises. It easily penetrates into small crevices and cracks on the floor and furniture, and gets into the pile of carpets. And if it is not removed in time, it will poison the human body, evaporating at room temperature. By inhaling mercury vapor, the human body accumulates it and after a while intoxication can occur. It manifests itself in the following symptoms: metallic taste in the mouth, drowsiness, decreased attention and memory, headaches, vomiting, diarrhea, kidney damage, abdominal pain, bleeding gums, stomatitis, anemia, dermatitis, tremors of the limbs, irritation of the respiratory tract. Mercury has an extremely negative effect on the body of children, elderly people and pets. Therefore, if a problem occurs when the thermometer turns out to be broken, you should immediately carry out a number of mandatory manipulations.
If the thermometer breaks
- The first thing you need to do is remove everyone from this room who is not involved in cleaning and eliminating the consequences of a broken thermometer, especially children and pets.
- They also immediately open the windows for ventilation, but it is important not to create a draft so that the mercury balls do not scatter over a large area. This will help reduce the air temperature in the room, and therefore the evaporation of mercury will slow down.
- If possible, limit the location of the accident using available means, preventing the mercury from spreading over a large area.
- Things that were in contact with the broken thermometer should be taken out into the fresh air (clothes, carpets, etc.).
- Prepare a glass jar or plastic bottle, which has a screw-on lid, put rubber gloves on your hands, shoe covers or plastic bags on your feet, and a gauze bandage on your face, which should be moistened with water or soda solution.
- First, we collect all visible mercury balls. This is done with two sheets of paper, a brush, cotton wool soaked in a solution of potassium permanganate or soda, a rubber bulb, a syringe, adhesive tape or tape. All collected mercury is placed in a jar or bottle with cold water. A rubber bulb or syringe will become convenient device in order to remove mercury balls from places with difficult access.
- Carefully inspect all the cracks on the floor (at the junction of the floor and the baseboard, between the laminate, etc.), if possible, disassemble everything possible designs to make sure there are no mercury balls there.
- Close the jar/bottle tightly and place it in a place out of reach of children, away from heating appliances. The best thing is to temporarily place this container on the balcony or in the garage. Next, it must be submitted to the Office of the Fire Service for Civil Emergency Situations.
- For safety reasons, when working to collect mercury, you need to go out into the fresh air every 15 minutes.
- Under no circumstances should you:
- Use a vacuum cleaner because heating element in a vacuum cleaner will contribute to the evaporation and distribution of mercury in the room. Subsequently, using such a cleaning device will be hazardous to health, so it will have to be disposed of.
- Use a broom, as its twigs will break the balls into smaller ones. This will make it difficult to collect the hazardous substance.
- Dispose of collected mercury in the trash or sewer. This will contribute to the contamination of a much larger area, making it difficult to clean up.
- Do not wash items that you have cleaned or items that have come into contact with mercury as a result of an accident. washing machine. In this case, mercury can also end up in the sewer system, from where it can no longer be removed. Things are taken outside and aired outside for at least 5 days.
- Once all the mercury has been collected, chemically treat the area. To do this, make a dark brown, almost opaque solution of potassium permanganate. For one liter of such a solution you need to add one spoon of salt and one tablespoon of vinegar (you can use citric acid). Using a spray bottle or brush, apply the resulting solution to the accident site and leave for 6-8 hours, periodically moistening the treated surface with water. Upon expiration given period, wash the floor with soap and soda solution.
- Such floor treatment should be carried out over several days, keeping the potassium permanganate solution for about an hour.
