3 mistakes we make when measuring body temperature with a thermometer

Water thermometers are used almost as often as devices for measuring air or human body temperature. But such a task arises in a variety of situations, and therefore there are many types of water thermometer. By taking into account the features of each type and basic tips for choosing them from professionals, you can avoid a lot of problems.

What is a water thermometer

This is a special thermal device necessary for measuring the temperature of water in a bathtub or other containers. The device is compact, has small dimensions and a streamlined shape, so it does not take up much space and should always be stored among household items. The water temperature meter is convenient for everyday use, and depending on its purpose, it provides the following conditional classification:

• aquarium thermometers (glass, electronic);
• children's (to measure the temperature of the baby bath water);
• electronic and digital (for household, everyday needs);
• mercury-free (a safe device that is used in pediatrics and beyond).

Types of water thermometers

In some baths, special temperature sensors (light or sound) are installed, but in domestic conditions this function is performed by a thermometer for hot water. Several well-known brands are engaged in serial production of such relevant products; the differences lie in the design, principle of operation, purpose and pricing policy of the rating positions. It's time to study each of the classifications and its prominent representatives.

Children's

The temperature of the water in an external baby bath should be no more than 37 degrees, otherwise bathing a newborn or infant can be harmful. Therefore, many young mothers choose not mercury, but more accurate digital models, which they actively use in everyday life. The choice is purely individual. Below are several rating items that can be ordered from the catalog and purchased in the online store at an affordable price:

• name: BabyOno Fish;
• price: 190 rubles;
• characteristics: mercury-free model for water, temperature range varies from +10 to +45 degrees;
• pros: bright color, original design, ease of use, affordable price, free sale, delivery by mail;
• cons: none.

This was a budget option; many people trust more expensive products, citing their high quality. The second no less reliable and time-tested water meter:

• name: Maman RT-17;
• price: 436 rubles;
• characteristics: electronic thermometer, for water, there is a sound signal;
• pros: child-friendly design, easy to use, compact size, protection from water ingress;
• cons: high cost.

If you are interested in cheaper products, here is one domestic item that is in high demand among modern mothers. Below is a brief description of it:

• name: Bebe confort 32000236/32000235/ 32000212;
• price: 370 rubles;
• characteristics: protected from water, temperature range from +10 to +45 degrees, mercury-free model;
• pros: stylish design, high accuracy of results;
• cons: cost.

Mercury-free

In recent years, such positions have become especially relevant, since they are considered the most reliable and safe for a child. Before making a choice, you need to study the rating of favorites and their features:

• name: Thermal device “Fish”;
• price: 75 rubles;
• characteristics: mercury-free, for water, protected;
• pros: original design, accurate measurements, ease of use;
• cons: none.

If buyers are more interested in imported products, there is a worthy alternative. The second name is well known to modern pediatrics and is the optimal price-quality ratio:

• name: Happy Baby 18003;
• price: 185 rubles;
• characteristics: mercury-free, used for water, temperature range varies from +10 to +50 degrees;
• pros: no mercury, original design, affordable price, reusable;
• cons: small markings.

Models without mercury are more practical and safe for children's health. The third version of the popular thermometer, common among the masses, is this:

• name: Bebe-Jou for bath;
• price: 735 rubles;
• characteristics: for water, has special protection, small scale, plastic body, mercury-free model;
• pros: convenient and stylish for everyday use, produces accurate results, works without failures;
• cons: not everyone is suitable for the inflated cost.

With dipstick

When choosing a thermometer to measure water temperature, many people prefer models with a probe. This is very convenient, since the thermal device is universal for kitchen and household purposes. The design is submersible, equipped with an indication. A thermometer for liquids and alcohol tinctures should be in every kitchen; below are the most rated models:

• name: TP101;
• price: 250 rubles;
• characteristics: electronic model of submersible type for water and oily liquids, presence of a probe, scope of application - domestic needs, cooking;
• pros: cheap, easy to use, necessary for everyday use;
• cons: completely absent.

Thermometers with a probe can be purchased at the pharmacy; be sure to check for integrity. The second, no less relevant offer from well-known manufacturers:

• name: ST-9231;
• price: 1500 rubles;
• characteristics: stainless steel thermometer with a plastic handle, built-in LCD display;
• pluses: convenient model for kitchen needs and cooking, availability of a cover;
• disadvantages: high cost, in case of malfunction it produces a high error rate.

This device is distinguished by its versatility, but some buyers are not satisfied with the price. A budget thermometer for measuring water temperature with a probe is described below:

• name: WT-1;
• price: 450 rubles;
• characteristics: metal probe, plastic handle, liquid crystal display;
• pros: convenient model, used for household needs, affordable prices;
• cons: none.

Electronic

Such devices are considered “favorites”; they have a large screen and large numbers. They are distinguished by high measurement accuracy, ease of everyday use, and a wide range of models and prices. When buying a thermometer for hot water, you need to pay attention to the following electronic items:

• name: Philips AVENT SCH550;
• cost: 900 rubles;
• characteristics: electronic thermometer, temperature range from +10 to +45 degrees;
• pros: stylish flower-shaped design, accurate results;
• cons: high cost.

How to measure temperature using various methods using an electronic thermometer?

There are several ways you can use an electronic thermometer:

• orally;
• rectally;
• in the armpit.

Using an electronic thermometer is not only much more convenient, but also safer. If the temperature is measured in the mouth or armpit, the algorithm of actions is practically no different from using a mercury thermometer. But there are also specific features. First of all, these include the time after which an accurate result can be obtained. It depends on the type of thermometer, as well as on the manufacturer. Usually there are instructions for this, which indicate how long it takes to see the result. For most models, this period of time ranges from 30 seconds to 1 minute. But in practice, things happen a little differently. If measurements are taken in the armpit area, then after the sound signal you must wait about 2-3 minutes without taking out the thermometer. Only after this period can the result be assessed.

Underarm measurements

When taking oral temperature, the correct readings will appear on the display immediately after the sound signal.

Oral temperature measurement method

The most correct and objective data are obtained by taking measurements through the rectum. There the temperature is as close as possible to the readings of the internal organs. Use this method for diseases of the rectum, as well as disorders of the digestive system. In addition, women planning pregnancy use this method to determine the days of ovulation. To get accurate readings, you must follow a few simple rules:

1. The tip of the thermometer is lubricated with Vaseline or oil before insertion into the rectum.
2. An adult should take a position lying on his side, a small child should be placed on his tummy.
3. Turn on the thermometer and wait until the start of the procedure appears on the display. It may differ from one manufacturer to another, so be sure to read the instructions completely before use.
4. Insert the thermometer into the rectum no more than 3 cm and hold it in this position between the straight middle and index fingers.
5. Squeeze your buttocks tightly while taking the temperature. This will help prevent cold air from entering.
6. Typically the procedure takes from 1 to 2 minutes.

A person should not stand up or make any movements during rectal temperature measurement. It is also prohibited to insert the device sharply into the rectum.

After the process is completed, the thermometer should be disinfected with a special solution.

How to choose a water thermometer

Before you buy a water thermometer for the bathroom or for culinary purposes, you need to carefully study the basic selection criteria. Otherwise, the purchase decision may turn out to be wrong, and the money will be wasted. Here are the main parameters for evaluating all commercially available thermometers:

1. Manufacturer and price. The two parameters are interrelated, and it is not recommended to skimp on your purchase. Rated manufacturers provide a quality guarantee, and the purchase will last for more than one year.
2. Model selection. For a child, it is better to choose mercury-free thermometers, for culinary purposes - with a probe, for a children's room - from hypoallergenic materials.
3. Functions. In this matter, it is advisable to give preference to universal positions that are suitable not only for measuring water temperature, but also air temperature.

How to check the serviceability of a thermometer?

If you doubt the accuracy of the thermometer readings, you can perform the following simple test using two thermometers and a glass of water. Take regular warm water and place both thermometers there. The data will be the same after three minutes. This will give you the opportunity to judge how well the thermometer is working. If the data from the electronic thermometer is very different, then you have a direct route to the service center.

By the way, the temperature test can be carried out not only on water, but also on yourself by measuring the temperature with a mercury and electronic thermometer. Remember the difference in readings and then simply add the missing degrees. Typically the difference is about 2 tenths. On mercury 36.6, on electronic - 36.4. On mercury 37.5 - on electronic 37.3.

Source: gubdaily.ru

Reviews

Arina, 31 years old A thermometer is an indispensable thing if you have a baby at home. I accidentally broke one, as if I had no hands until I bought a new one at the pharmacy. In this matter, it is better not to save money, but to buy electronic options. Very convenient, accurately, quickly and accurately shows the temperature. I recommend everyone to buy it, because I myself suffered greatly without it.

Lada, 24 years old I am not at all delighted with mercury-free temperature meters, since they give a high error. I have experienced such inaccuracies myself. It’s better to buy an electronic one right away and not suffer. It costs an order of magnitude more, but it works properly, without failures. When an infant is growing at home, this is very important. I use the device before bathing him and am very pleased.

Margot, 35 years old I don’t understand why such home meters are needed when you can check the temperature in a baby’s bath using the old-fashioned method – with your elbow. It works properly, without failures and unnecessary costs. There are two thermometers at home, but they are lying around unnecessarily, although during pregnancy, on the recommendation of a gynecologist, as an exemplary mother, I bought them at the pharmacy.

Inga, 26 years old I have one device for measuring both water and room temperature. Convenient and without extra financial costs. I don’t recommend spending too much on such a purchase; anyway, you’ll only need to use it from time to time. The doctors insisted on purchasing a separate children's thermometer, but even without it I manage not to scald my own child with boiling water.

Textbook for 6th grade PHYSICS

Every morning, when getting ready for work or school, we ask: “What is the temperature outside?”, meaning by this how warm or cold the outside air is.

What is temperature? Temperature determines the degree of body heat. How to measure it? Are our sensations of heat and cold enough for this?

Let's conduct an experiment. Pour water of different temperatures into three glasses (Fig. 93). Place your right hand in glass 1 with cold water, and your left hand in glass 3 with hot water. After 2-3 minutes, lower both hands into glass 2. The water in glass 2 feels warm in the right hand, and cold in the left hand. This suggests that our sensations are subjective. To objectively assess the degree of heating of a body, i.e. its temperature (denoted by the letter t), a measuring device is used: thermometer .

How I measured the temperature of tap water

On the eve of summer, the hot water was turned off, and apparently for a long time.
My mother puzzled me with the choice of an instantaneous water heater - a sort of box with a tap that passes water through itself and heats it up. I dug into the catalogues, and it turned out that they come in different powers, from 2 kW to 15 kW, and the more powerful, the more expensive, and at higher powers you need to run a separate line from the electrical panel.

We, of course, need something cheaper, ideally around a couple of thousand rubles, and without unnecessary hemorrhoids, since we will only use it until our hot water is turned on.

I found a handsome guy with a good brand and reviews for two and a half thousand rubles and a power of 3.5 kW. Those who have already used it write that the thing is wonderful and does what we need, under one condition - the temperature of the water from the water supply must be at least 18 degrees, otherwise the heater simply will not have enough power.

That is, if our water turns out to be so cold, due to power and budget limitations, there is no point in buying such a water heater at all.

I touched the water - it was cold. Unclear. It needs to be measured.

I looked for a thermometer and found a simple human one, with a scale from 35 to 42 degrees. They can't measure it. Leaving the house and looking for another thermometer somewhere is lazy.

I creaked my brains and remembered a school physics course about specific heat capacity - the amount of energy that needs to be imparted to one kilogram of a substance to raise its temperature by one degree.

I decided that by measuring the time it takes our kettle to boil a liter of water - i.e. will raise its temperature to 100 degrees, knowing the power of the kettle, it will be possible to calculate the initial temperature.

Specific Heat Capacity Formula:

Where C is the specific heat capacity. I took the heat capacity of water from Wikipedia.

C = 4.187 kJ/kg * Kelvin

m is the mass of the substance. In our case, everything is simple, 1 liter of water has a mass of 1 kg.

dT – delta T – temperature difference.

dT = 100° – T, i.e. boiling point minus the initial temperature, which is what we're trying to find.

Q is the amount of heat, J. In our case, heat transfer does not occur instantly, but over time. In the absence of other options, we simplify:

where P is the power of the kettle in Watts (1 Watt = 1 J / 1 sec),

and t is the time to boil.

I looked at the bottom of our electric kettle - the power indicated is from 2000 to 2400 W, but the kettle operates at an alternating current frequency of 50 or 60 Hz, and a voltage of 220V or 230V.

It seems that in Russia the network is 50 Hz, and exactly 220 V, so with peace of mind we assume that the power = 2000 W.

My younger brother is a fan of this kind of everyday physics, so I explained to him what we were doing, gave him a stopwatch, a “researcher’s notebook” and told him to measure eternity - wait until the kettle boils, into which I carefully poured 1 liter of tap water.

Time t was measured as 3 minutes 26 seconds, or 206 seconds.

Let's substitute all our data into the formula:

4.187 kJ / kg * Kelvin = 2 kW * 206 sec / 1 kg * (100 °C – T °C)

100 – T = 2 * 206 / 4.187

T = 100 – 98.4 = 1.6 °C.

Something is clearly not right. The water is, of course, cold, but not icy!

Well, from the very beginning it was clear that the calculation method was far from ideal, because an electric kettle does not have an efficiency of 100%. It is he who takes 2 kW from the power grid, but how much reaches the water?

This efficiency also includes the heat that the water dissipates while the kettle heats it.

Not to mention that water has different specific heat capacity at different temperatures.

Thus, in our formula for heat capacity, next to the power of the kettle, another unknown is added - efficiency:

C = P * t * efficiency / m * dT

I immediately understand that in order to calculate this efficiency, you need to find out how long it takes a kettle to raise water of a known temperature to one hundred degrees. That is, as my brother put it, “to calculate the temperature of water, you need to know the temperature of the water.”

The only measuring device in the house is the aforementioned thermometer with a tiny scale, and it can only measure the temperature of water close to the temperature of the human body.

My mother suggested a solution: dilute cold water with boiling water until the water feels neutral to the touch, and then measure the temperature with a thermometer.

This is what they did, using the salad bowl as an intermediate container. Measured. It turned out to be 38 °C.

Carefully pour 1 liter of water into the kettle and measure the time to boil: 2 minutes 42 seconds, or 162 seconds. Again, we substitute everything into the formula and calculate the efficiency:

C = P * t * efficiency / m * dT

4.187 = 2 * 162 * efficiency / 1 * (100 – 38)

Efficiency = 4.187 * 62 / 324 = 0.8, or 80%. Not bad, by the way, and within the expected limits.

Now that the efficiency is known, we can again calculate the temperature of the tap water:

4.187 = 2 * 202 * 0.8 / 1 * (100 – T)

100 – T = 323.2 / 4.187

T = 100 – 77.2 = 22.8 °C.

Voila. Warmer than I expected, but in principle it seems to be true. I know that it’s essentially bullshit, but I still spent the rest of the day smug, so I decided to show off before the peek-a-boo.

Source: pikabu.ru

Is it possible to measure water temperature with an outdoor thermometer?

If you need to find out the temperature of the water, but you only have an ordinary medical thermometer at hand, great. Using an existing thermometer, you can accurately determine the water temperature parameters.

The only condition for this method to work is that the thermal indicators of the water must be within normal limits, that is, the liquid is not heated to boiling water.

The rest of the article describes how to correctly find out the water temperature using a regular thermometer.

Water temperature measurement process

First you need to prepare the thermometer itself. It is advisable to find a household option, since a medical thermometer will show incorrect results at a water temperature of more than 45 degrees.

The household variety works correctly up to 50 degrees.

It is not recommended to use a mercury thermometer if you are measuring the water temperature in an aquarium. Using the thermometer this way can lead to the death of aquarium inhabitants if mercury gets into the liquid.

Measurement without a thermometer

It is impossible to determine the exact temperature of water without a thermometer. This way you can only determine the level of heat. It is impossible to obtain specific information without a thermometer.

You can estimate the water temperature by dipping your elbow in the water. If the liquid feels comfortable, its approximate temperature is 36 degrees. This method is often used by mothers to determine whether the water is comfortable enough for the child.

Now you know how to correctly measure the temperature of water using a regular thermometer, as well as a way to estimate how hot the liquid is if there is no thermometer.

An immersion thermometer is a special device designed to measure water temperature. It is an integral part of the household if there are small children or decorative fish. Currently, this type of measuring device is widely used in human life. They measure the water temperature for a child’s comfortable bathing, as well as in swimming pools, fish aquariums, and on beaches. At home in the kitchen, a water thermometer can be useful for canning, because the scale of such a thermometer reaches +100 °C.

How long should you keep an electronic thermometer?

Most electronic thermometers are equipped with a sound sensor that notifies you that the temperature has been measured. But you shouldn’t delude yourself. Most instructions indicate that the beep does not indicate the end of the measurement. Your temperature may rise slightly by 0.3-0.4 degrees. So it’s better to hold the thermometer longer. Or remember the difference that the thermometer shows a few minutes after the sound signal and add it in the future. Usually the difference is 0.3-0.4 degrees, but it is better to check it yourself.

By the way, in the USA, temperature is measured mainly in the mouth, and not in the armpit. The thermometer in the armpit does not have time to warm up. Even expensive models of thermometers with a larger sensor, specifically designed for measuring under the arm, show 0.2-0.3 degrees less. So you can try to measure the temperature using the American method.

Purpose of an immersion thermometer for water

Most often, these devices are used to measure water temperature while bathing babies. This allows you to make water procedures as comfortable as possible and not harm the child. It is recommended to choose the right reliable device to make your baby’s life safe and interesting.

First of all, when buying an immersion thermometer for water, you should not save, because the price in this matter directly depends on the quality of the device, measurement accuracy, safety and aesthetic appearance. Well-known manufacturers guarantee durable use of modern products.

If an immersion thermometer is chosen for bathing a child, then, of course, it is best to purchase a device that does not contain mercury. The filler in this case is alcohol or rapeseed oil. Devices for measuring water in a baby bath in most cases have an increased safety class - they do not break, do not have sharp corners, and are large enough in size so that the child does not accidentally swallow it.

There are thermometers already built into the baby bath. The advantages are that you do not need to separately look for a water thermometer that meets all safety requirements; it will always be at hand, will not get lost, and the water temperature can be controlled throughout the entire duration of the procedure. Such devices are made from hypoallergenic materials that will not harm the baby’s health.

For culinary purposes, where the temperature of the liquid can reach +100 degrees, probe thermometers are used.

To save the family budget, it is recommended to purchase universal thermometers. They are equally suitable for measuring the temperature of both water and air.

Manufacturers

A good choice might be the Canpol model 220718001 . This device does not contain even traces of mercury. The shape of the baby thermometer is specially selected to make it more fun for kids. But not everyone needs “children’s” devices. Sometimes more solid equipment is needed.

Then Steklopribor TB-3-M1-2 . Its plastic body is quite reliable. The temperature threshold is 0 degrees Celsius.

The device can help out home canning enthusiasts and other non-professional cooks.

The dry weight of the product is 0.17 kg, and the price of one division is equal to 1 degree.

When choosing a thermometer with a probe, you should pay attention to Espada Thermo TA-288 . This electronic device is also housed in a high-quality plastic case. It can measure temperatures up to 300 degrees. The device is optimized for culinary use. Dimensions of Thermo TA-288 – 0.04x0.03x0.03 m.

Baby thermometer

The optimal water temperature for bathing a newborn is 37 degrees. It happens that when a child is immersed in water, he begins to cry, and the point is not that he does not want to swim. Most likely, the temperature of the water in the bath is uncomfortable for him. It is quite difficult to determine whether the water is hot or cool with your hand or elbow, so if you have a baby in the house, a children's immersion thermometer for measuring temperature is extremely necessary.

There are classic measuring instruments - mercury, alcohol, oil. These are budget options. The disadvantage of such thermometers is that you need to wait some time to correctly determine the temperature.

Main criteria for selection:

1. Reliability. It is best if the case is unbreakable and waterproof.
2. Occupancy. Priority is alcohol or oil.
3. External attractiveness. Often, children's water thermometers are made in the form of animal figures - dogs, fish, hippos. In this case, you can measure the temperature, and the new toy will delight the baby.

Do you need a water heater?

In apartment buildings there is no direct need to install a water heater . Hot water is no longer a luxury, but a common condition of normal life. However, for particularly heat-loving residents, there are indirect reasons for installing it. Namely :

• Reluctance to remain without hot water in the summer . During the planned annual shutdown of hot water or during repairs to the water supply system, a storage water heater will solve the problem. If other residents are forced to heat water, say, on a gas stove, the owners of the water heater relieve themselves of such responsibility;

• Reluctance to remain without hot water even for a short period of time . Due to accidents in the apartments of other residents and while they are being eliminated, hot water is usually turned off . If an hour or a day without hot water is a big problem, buying a water heater is an excellent solution to eliminate it.

A high-quality water heater is also necessary in private homes where there is initially no . This device will greatly simplify the life of the inhabitants of the house and relieve them of the need to constantly heat water.

So, if interruptions in hot water or its constant absence in the house are your daily life, install an electric storage water heater. The impressive volume of the storage tank of modern heater models ( up to 150 liters ) will allow you not to save on hot water.

In addition, water from pumps and wells, which is often used by residents of private houses, can pose a danger to human health - it may contain harmful viruses and bacteria. Before drinking well water, it is recommended to purify or simply boil it.

It is possible that without a water heater the water temperature suitable for disinfection will not be reached. When heating “manually” it is difficult to control the temperature, and the water heater guarantees sufficient heating of the water.

To summarize , the minimum permissible temperature of hot water in places of collection is 60°C , and the maximum is 75°C . These indicators are determined by the requirements of safety and protection of public health.

Any discrepancy between temperature indicators and hot water standards must be corrected . You cannot neglect the situation when warm water flows from a “hot” tap. If this is caused by a breakdown of the water supply system, it needs to be repaired. If the service company is at fault, restore your right to recalculate water charges.

What should be the temperature of hot water in the tap, you will learn from this video :

Source: anatomia-remonta.ru

Electronic temperature meter

This device is considered a favorite; it has a large screen, large numbers, and a diverse range of models. Very accurate and fast in measurements, instantly determines the water temperature. The devices have an additional option - an indicator in the form of a “hot”, “cold”, “normal” icon, which helps to quickly navigate to the optimal temperature regime. The downside of this device is the high price, so not everyone can afford the electronic version.

Aquarium

Not a single home with its own fauna can do without such a thermometer; it is necessary daily for measuring the temperature in aquariums. There are electronic models and simple ones with a measuring scale - a very affordable option.

In order to choose the right immersion thermometer, you need to know exactly in which area it will be used. Otherwise, the money will be wasted, and unnecessary things in the household will clutter up the home.

Is it possible to measure water temperature with a room thermometer and explanation

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Thermometer for 132 rub. They can measure a lot of things, they just have to wait.

With the birth of the child, due to the fact that there was no breast milk, there was an urgent need to prepare milk formulas, and since formulas require a strictly defined water temperature and it is completely unhygienic to determine it with a finger, we needed a thermometer.

If the water temperature for the mixture is lower than required, not all components will dissolve, and if it is higher, some vitamins will die.

I couldn’t find suitable devices for this in the stores in our city; there were options on the Internet to buy specialized thermometers for sessions, based on an indicator strap with liquid crystals, as well as infrared non-contact ones. Since the accuracy of their measurements was in question and the cost of delivery was too expensive for me, I decided to order the gadget from Ali.

It arrived quickly, in 3 weeks.

1. Main characteristics of the thermometer
2. Composition and management.
3. What can it be used for?
4. Measurement in practice. Measuring speed
5. Cooking temperature
6. conclusions

Direct link to the product.

1. Characteristics

Measurement step – 0.1 degrees Celsius

Accuracy: +-1% when measuring up to + 80

+- 5% when measuring from +80

Range: – 50 to + 300