Outdoor thermometer on a plastic window - new technologies or old-fashioned method. Frames for thermometers

Time-tested technologies are used for mechanical temperature measurement. Such as bimetallic and gauge measuring principles made of various materials with scale ranges from -100 to +500 ° C in various accuracy classes and response times. Process connection options, stem diameters and lengths allow you to choose the right solution for any application.

Mechanical indicating thermometers WIKA, with a capillary, provide simplicity and convenience in operation. All WIKA thermometers can be fitted with a thermowell if required. Various models of thermomanometers are also available for selection - a combined pressure and temperature meter (100.12, MFT, etc.).

WIKA A43 - Bimetallic thermometer for heating systems

Bimetallic thermometer model A43 was developed for simple measurements in heating systems.

The design is modular, thanks to which various combinations of body materials, nominal sizes, measuring ranges and stem lengths can be manufactured. This allows you to preserve the design of the customer, without introducing additional changes.

The A43 comes standard with a thermowell that allows measurements up to a maximum pressure of 6 bar.

Model A43 is manufactured with accuracy class 2 in accordance with EN 13190, which provides the required display accuracy for heating technology.

WIKA 46 - Bimetallic thermometer with thermowell, range up to +120 ° C

The model 46 bimetal thermometer is mainly used in heating, air conditioning and refrigeration units for monitoring the temperature of processes.

To measure the temperature, a bimetallic thermometer is installed in the process together with a thermowell. On the one hand, this protects the thermometer from damage, and on the other hand, no cleaning of the heating system is required to replace it.

WIKA 50 Bimetallic thermometer with thermowell, range up to +200 ° C

The thermometer Model 50 is intended for use in heating, air conditioning, ventilation and refrigeration technology, for measuring ranges up to 200 ° C. To measure the temperature, a bimetallic thermometer is screwed into a thermowell and placed in the process. This protects the thermometer from damage, on the one hand, and on the other hand, to replace it does not
you want to stop the process.

WIKA 52 - Bimetallic thermometer for axial and radial process connection, range up to +500 ° C

The bimetallic thermometer of this series was designed specifically for installation in pipes and tanks.

The bimetallic thermometer uses bimetallic plates as a measuring element. Bimetallic plates are metals that have different coefficients of linear expansion when measuring temperature. They are twisted into a helical spiral, the other end is fixed to the movable axis. When measuring the temperature, the spiral rotates in proportion to the magnitude of the change, the transmission occurs through the axis and then through the tube-sector mechanism to the arrow.

WIKA 70 - Liquid thermometer with capillary, stainless steel housing

Due to its versatile design, this type of liquid thermometer has found wide application in mechanical engineering, in the refrigeration industry and in air conditioning systems. A liquid thermometer can be installed at almost all measuring points. The capillary model is used for measurements at points that are difficult to access or that are at a considerable distance.

The body, capillary and stem are made of stainless steel. For optimum adaptation to the measuring process, there are available different lengths capillary, with a maximum length of up to 10 mm and a form of connection.

WIKA 32 - Industrial glass V-shaped thermometer

Industrial glass thermometers - Model 32 are mainly used in various industries such as mechanical engineering, energy, refrigeration.

A feature of these thermometers is their high accuracy and durability (due to the absence of mechanically wearing parts).

WIKA 100.12 - Thermomanometer, pressure and temperature measurement with one device

The thermomanometer with a bimetallic system is installed directly at the measuring point through the stem. The presence of the valve allows you to unscrew the measuring device without draining the water from the heating system. Thanks to the combination of a pressure gauge and a bimetallic thermometer, the measuring device finds a wide range of applications.

WIKA IFC - Gauge thermometer with capillary

The IFC capillary thermometer is a versatile gauge thermometer for mechanical engineering, refrigeration and food industries, as well as heating, ventilation and air conditioning systems.

Temperature measurement takes place due to the expansion of the thermometric liquid in the capillary.

This type of capillary thermometer is used to measure temperature in hard-to-reach places, as well as in places that are at a considerable distance.

Thanks to its simple design and plastic housing, the IFC capillary thermometer is an inexpensive and very reliable measuring instrument.

WIKA TF58, TF59 - Gauge thermometer with capillary

Liquid thermometer, models TF 58 and 59, - measuring instruments with a drum-type scale.

Different versions have different accuracy, scale range, dimensions, fixing and panel frame design.

WIKA MFT - Thermomanometer with remote line and capillaries, measurement of pressure and temperature with one device

The thermomanometer is installed in the panel and allows you to measure pressure and temperature at the same time. The thermomanometer has compact design with front flange and side latches, making it easy to install and integrate into the ergonomics of dashboards. The capillary simplifies the possibility of remote mounting of the indicating part of the device and the measuring point.

The thermomanometer has a Bourdon tube as a sensitive element for measuring pressure. A liquid-filled manometric thermometer is used to measure the temperature. A liquid temperature filling thermometer converts the change in pressure within the closed system of the hollow tube and capillary into temperature and transmits this rotation to the pointer.

Among the assortment of the Tekhnoavtomatika company there are industrial thermometers showing. The main purpose of the devices is a continuous indication of the physical processes occurring in the studied environment (the degree of heating). Bimetallic devices from WIKA are distinguished by ease of installation, wide operating range and long service life. The specific environment where the use of indicating thermometers is allowed is determined by the parameters of the material resistance of the performance (body, thermowell).

Classification of indicating thermometers

Splitting in two large groups according to the method of installation, it determines the scope of use of the measuring equipment. Devices with a rigid coupling represent a group of thermometers operating directly at the control point, where both the thermal bulb and the indicator are installed. If the thermal bulb is installed remotely from the indicator, this significantly expands the scope of the device, excludes the presence of a person in places hazardous to health.

1. Bimetallic thermometers. The name of the devices comes from the principle of operation. Under the robust body (the shape of a typical industrial thermometer is round) there is a sensing element consisting of two elements with different thermal coefficients of linear expansion. Depending on the magnitude of the temperature effect, the plates are deformed (expanded) and, depending on the form of execution, transfer the force to the arrow of the device.

Depending on the specific model of the device, the maximum value of the temperature range can reach up to 200 degrees. Scope of application: heating and ventilation systems in various industries. The devices are completely autonomous, supplied with an electrical output signal for communication with the control room.

2. The scope of application of thermometers showing electrical contact is much wider. Automatic devices allow you to take over part of the technological process for the control and regulation of the temperature of liquid, viscous and gaseous media. The WIKA series of electrical contact devices provide monitoring to maintain a safe production environment.

3. Gauge thermometers are well suited for special, sterile conditions. These are the food and pharmaceutical industries. The principle of temperature measurement in the investigated media is based on the standard pressure of a certain volume of substance, depending on. Distinctive features liquid thermometers of this group are of hygienic design and high measurement accuracy.

The Tekhnoavtomatika company offers whole line modern innovative devices fully adapted to the conditions of your production. The cost of the signaling thermometers is suitable for any applicant's budget. Call, find out the prices, and we can always find the most suitable solution for you.

One of the anachronisms that has migrated into the life of a modern person is a street thermometer, according to established habit, screwed or glued onto the window frame in order to determine the air temperature outside. Why anachronism and why is it not needed? We will try to tell you in the article offered to your attention. Outdoor thermometers on plastic windows are installed everywhere. In most cases, without even thinking about whether it makes sense to waste time on this useless activity.

But, since there is such a need for a certain category of citizens, we, of course, will answer the questions of how best to do this.

Do you need a thermometer behind a plastic window?

From the time of their invention and until the recent historical past, street thermometers at the very least coped with their duties - to show the air temperature outside. Just like today and fifty and a hundred years ago, they shamelessly lied. This was not due to the peculiarities of the devices themselves, but to the fact that they were installed, wherever and how haphazardly. Therefore, there were often cases of disputes about how cold or hot it is on a particular day. The debaters simply forgot that the street thermometers they were guided by were placed in different conditions. Some have it on the window illuminated by the Sun in the morning, others have it on the frame of an eternally shaded balcony, and still others have it on a post in the courtyard of a private house.

In the 21st century, the need for this device outside the window has completely disappeared. Almost everyone has a cell phone or smartphone, which with one touch can show on the display absolutely accurate and objective data on air temperature, humidity, wind strength and "subjective" sensations of the weather, if necessary, adding to the readings the value of atmospheric pressure and the forecast for precipitation for the next day or a whole week.

But the force of inertia of thinking and habit is so strong that instead of not getting out of bed to find out what the weather is waiting for you on the street, many wander to the street thermometer outside the window and with joy or sorrow learn that the weather is not at all like this outside, what they dreamed in a dream.

A little about thermometers (thermometers)

Traditionally, in everyday life, two types of thermometers are used to measure the air temperature outside: alcohol and bimetallic.
The former are a hermetically sealed capillary tube with colored alcohol, which, as the temperature rises or falls, the air either expands or contracts, sliding along the capillary along the applied metric scale.

Bimetallic thermometers are a spring consisting of an alloy of two metals with different coefficients of expansion, at the end of which an arrow is installed. When heated or cooled, the spring is either compressed or unwound. In accordance with this, the arrow located at the end of such a spring also moves, showing a certain value on an arcuate degree scale.

The third type of outdoor thermometers are electronic, which receive signals from an outdoor sensor and transmit it to electronic device displaying the temperature in digital form on the LCD display.

Currently, these three models are approximately equally common and are the subject of endless complaints from owners about the quality of devices and a reason for mathematical calculations of the arithmetic mean, in the event of a discrepancy between the readings on two or more thermometers.

The most accurate readings, all things being equal, are given by electronic thermometers. Since their external heat-measuring elements undergo stricter metrological control (except for Chinese ones) and their temperature sensors can be attached in places inaccessible to direct sunlight.

Bimetallic thermometers are the least reliable. The average and most popular position among the population is occupied by alcohol thermometers. But you should take into account the age of the device. The longer he serves you, the more he deceives you. This is due to the gradual evaporation of the alcoholic liquid and its condensation in the upper part of the capillary.

As a result, the column of colored liquid becomes gradually shorter and shorter, and the temperature outside is getting "lower" and "lower".

What to do to prevent the thermometer from lying?

It is almost impossible to get absolutely reliable information about the air temperature from a street thermometer located on the frame of a plastic window. The first is heat radiation from the home. If it is known that up to 30% of the heat is lost through the windows, then, accordingly, the radiated heat will make adjustments to the readings of the thermometer in the direction of increasing temperature.

The second factor is the incorrect installation of the thermometer. They are usually mounted on windows, which provide the easiest and most constant access. it kitchen windows or windows in the bedroom. At the same time, few people think about checking the compass or the 2GIS program before installing the thermometer and determining in which direction your plastic windows are oriented. If in the east - the thermometer will "lie" in the morning, if in the west - in the late afternoon, if in the south - throughout the day. This is due to solar activity. Even in cloudy weather, the southern wall of the house will warm up more and the heat emanating from it will not allow your thermometer to show a reliable temperature.

The most accurate readings as possible are given by outdoor thermometers located on the north side. They are objective because they are not affected by direct sunlight.
The third mistake that affects incorrect readings is ignoring the requirements for thermometer shielding. It must be covered from the outside with a reflective screen, which will protect it from the influence of direct solar radiation.

The fourth condition is that there is sufficient clearance between the thermometer and the wall (not even the frame or glass) of the house.
It follows from this that without observing these conditions, you will always get very approximate readings in the range of +/- 3-5 ° C.

Installing a thermometer

If the above arguments did not convince you, and you still want to attach a thermometer outside your window, then carefully consider its choice. As already noted, the largest errors are given by bimetallic thermometers. This is due to the fact that it is very difficult to select and calibrate the scale for each specific spring located inside the device. A deviation of the thickness of one of the metal strips by several microns is enough for the readings of the two thermometers to differ. In mass production, no one makes their own scale for a particular spring. Therefore, thermometer readings are inaccurate.

The most common alcohol thermometers can serve you for many years, but every year their readings, as the liquid evaporates, will differ in the direction of "lowering" the temperature. When choosing an alcohol thermometer, one should strive to buy a device with as long a capillary tube as possible. Numerous souvenir thermometers equipped with paper scales inside the flask are not initially calibrated and show the temperature with large errors.

If you opt for an electronic weather station, then its choice will depend solely on your financial capabilities and the number of functions that the device can perform.

It is best to fix the thermometer not on the frame of a plastic window, since reliable fastening is possible only by mechanical screwing with plastic screws. And spoiling the profile for the sake of installing a thermometer is hardly worth it. You can glue the thermometer, after rinsing and degreasing PVC profile, on double-sided tape, but it is very short-lived and one fine day you may not find a thermometer outside your window, the reason for this may be birds, especially curious titmouses, which are ready to nestle on any surface.

Can be glued with construction transparent adhesives used for PVC plastics or transparent plumbing silicone sealant... It is not recommended to glue with Secunda adhesives containing cyanoacrylate. Despite its outstanding qualities in terms of the speed and strength of the initial setting, the substance itself, under the influence of air humidity and UV radiation, decomposes rather quickly and after about a year the glue ceases to hold.

Therefore, the best option would be to fix the thermometer on the wall of the house on an outrigger bracket and fix it with small screws or nails. Do not forget to equip the thermometer with the simplest home-made screen made of foil-clad material, which will protect it from the direct rays of the Sun. The thermometer should be fixed on the side of the non-opening sash of the window so that the sash, slightly open for ventilation, does not make adjustments to the readings of the device due to the warm air from the room.

Indicating thermometer - a device for measuring temperature at various industrial enterprises... Bimetallic thermometer (BT thermometer) refers to technical devices designed for measuring the temperature of liquids and gases in heating and sanitary installations, in air conditioning and ventilation systems, as well as for measuring the temperature of bulk and viscous media in the food industry.

The principle of operation of a technical thermometer is based on the dependence of the deformation of the sensitive element (bimetallic spring) on ​​the measured temperature. The spring is made of two firmly connected metal plates, which have different temperature coefficients of linear expansion. When the temperature changes, the spring bends and rotates the thermometer needle. One end of the bimetallic spring is fixed inside the stem, and an arrow is attached to the other (except for contact thermometers with a spring for mounting on a pipe, in which the bimetallic spring is wound around the axis of the contact element, and the arrow is attached directly to the bimetal).

Depending on the type of stem connection to the body, BT thermometers are divided into rear (axial) and radial. The body of the device is made of chrome-plated or stainless steel. Stem material - brass or stainless steel.

Thermometer modifications

Industrial thermometer BT can be produced in several modifications, which differ in design and materials of components:

• general technical series 211 with chromed steel body and stainless steel stem;
• general technical special with a body made of galvanized steel and a spring for mounting on a pipe;
• general technical special made of stainless steel and a stem in the form of a needle;
• corrosion resistant 220 series stainless steel.

The bimetallic thermometer is completed with a threaded brass thermowell. Exceptions are BT technical thermometers of corrosion-resistant design (series 220) with a stem, ring and stainless steel body, as well as general technical special BT thermometers (with a measuring element in the form of a needle and contact BT with a spring for mounting on a pipe). The industrial corrosion-resistant thermometer of the 220 series has a thread on the stem, and the thermometer is not included in the standard delivery.

A thermometer is a device designed to measure the temperature of a liquid, gaseous or solid medium. The inventor of the first temperature measuring device is Galileo Galilei. The name of the device is translated from Greek as “measure heat”. Galileo's first prototype was significantly different from modern ones. In a more familiar form, the device appeared more than 200 years later, when the Swedish physicist Celsius took up the study of this issue. He developed a system for measuring temperature, dividing the thermometer on a scale from 0 to 100. In honor of the physicist, temperature levels are measured in degrees Celsius.

Varieties according to the principle of action

Although more than 400 years have passed since the invention of the first thermometers, these devices are still being improved. In this regard, all new devices appear based on previously unused principles of operation.

7 types of thermometers are currently relevant:

• Liquid.
• Gas.
• Mechanical.
• Electrical.
• Thermoelectric.
• Fiber optic.
• Infrared.

Liquid

Thermometers are among the very first devices. They work on the principle of expansion of liquids with temperature changes. When a liquid heats up, it expands, and when it cools, it contracts. The device itself consists of a very thin glass bulb filled with a liquid substance. The flask is applied to a vertical scale made in the form of a ruler. The temperature of the measured medium is equal to the division on the scale, which is 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 devices are capable of measuring temperatures up to +600 degrees. Their disadvantage is that if dropped, the bulb may break.

Gas

They work in the same way as liquid ones, only their flasks are filled with an inert gas. Due to the fact that gas is used as a filler, the measuring range is increased. Such a thermometer can show the maximum temperature in the range from +271 to +1000 degrees. These devices are usually used for taking 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 bit like an analog clock. Similar devices are used on the dashboard of cars and various special equipment. The main advantage of mechanical thermometers is their durability. They are not afraid of shock or shock like glass models.

Electrical

The devices work according to the physical principle of changing the resistance level of a conductor at different temperatures. The hotter the metal, the higher its resistance to electric current transmission. The sensitivity range of electrothermometers 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 in laboratories.

Thermoelectric

The thermometer has 2 conductors in its design, which measure the 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 optic. These are very sensitive sensors that can measure temperatures up to +400 degrees. Moreover, their error does not exceed 0.1 degrees. At the heart of such a thermometer is 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, which 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 measured surface and displays its temperature on a small screen. In this case, the accuracy may differ by several degrees. Such devices are used to measure the heating level of metal blanks that are in the hearth, engine housing, etc. Infrared thermometers are able to show temperatures 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 commonly referred to as 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 version, medical thermometers are:

• Glass.
• Digital.
• Pacifier.
• Button.
• Infrared auricular.
• Infrared frontal.

Glass thermometers are 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 the real body temperature. For axillary execution, the waiting time is at least 5 minutes.

Digital thermometers have a small screen that displays body temperature. They are able to show accurate data 30-60 seconds after the start of the measurement. When the thermometer receives the final temperature, it creates a sound signal, after which it can be removed. These devices can work with an error if they do not fit very tightly to the body. There are cheap models of electronic thermometers that take readings as long as glass ones. 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 give a musical signal after the measurement is completed. The accuracy of the devices is 0.1 degrees. In the event that the baby begins to breathe through the mouth or cry, the deviation from the real temperature can be significant. The measurement time is 3-5 minutes.

Thermometers buttons are also used for children under the age of three. In shape, such devices resemble a pushpin, which is placed rectally. These devices take readings quickly, but have low accuracy.

Infrared ear a thermometer reads the temperature from the eardrum. Such a device is capable of taking measurements in just 2-4 seconds. It also has a digital display and works 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 in adults, since babies have too thin an ear canal into which the thermometer tip does not pass.

Infrared frontal thermometers are simply applied to the forehead. They work on the same principle as the 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, they can be used to measure the body temperature of the child without waking him up. The speed of the forehead thermometers is a few seconds.

Household for air

Household thermometers are used to measure the air temperature outdoors or indoors. They are usually performed in glass version and filled with alcohol or mercury. Typically, the range of their measurement in the street version is from -50 to +50 degrees, and in the room from 0 to +50 degrees. Such devices can often be found in the form of interior decorations or a magnet for the refrigerator.

Kitchen

Kitchen thermometers are designed to measure the temperature of various foods and ingredients. They can be mechanical, electrical, or fluid. They are used in cases where it is necessary to strictly control the temperature according to the recipe, for example, when making caramel. Typically, these devices come with a sealed storage tube.

Industrial

Industrial thermometers are designed to measure temperatures in a variety of systems. They are usually devices mechanical type with an arrow. They can be seen in the water and gas supply lines. Industrial models are electrical, infrared, mechanical, etc. They come in the widest variety of shapes, sizes and measuring ranges.