One of the important physical parameters, which are often studied, observed and corrected, whether everyday household human life, production cycles or laboratory tests is outside temperature.Depending on the properties, technical characteristics and determine the mechanism of work there is a classification of temperature measuring devices for certain types: the conventional liquid devices or complex, advanced electronic and laser measuring instruments, which are a great alternative have become familiar household thermometer.Of course, the fundamental and decisive factor is the place of the use of such devices.
Types of temperature measuring devices
devices to conduct the necessary investigations, including a device for measuring the temperature of the air, structurally different, as well as the principle of operation, which is used for measurement.It is enough to have wide application contact and remote thermometers, otherwise called pyrometers.In addition, the classification of temperature measuring devices includes:
- Glass and metal expansion thermometers Liquid working on the property changes in the volume of bodies at different temperatures.The spectrum of action of from -190 to +500 ° C.
- actuated thermometers, using the relationship between the changing temperature of the gaseous substance, placed in a closed volume, and pressure.They work for the values from -160 to +600 ° C.
- Electrical resistance thermometers are relying on the ability of materials to change the electrical resistance of the conductor during heating and cooling.Effective for values from -200 to +650 ° C.
- Thermoelectric converters - thermocouple.Are utilized in a range of 0 to +1800 ° C.These instruments are used to measure the temperature properties of two different metals and ferro alloys develop electromotive force when changing the degree of heating junction.
- device for determining the temperature from +100 to +2500 ° C - radiation pyrometer (photovoltaic, optical, radiation).Effects due to the fact that the lockable outside affects the amount of heat emitted by the body.It refers to the type of non-contact measurement.There are stationary and mobile, low and high temperature pyrometer.
thermometers and sensors
As a heat-classification device is conducted their separation on thermometers and temperature sensors.
first - is the mechanical equipment, including gas-filled Barometric devices, bimetal, temperature gauges, glass and combined controllers.
Thermal sensors - is ultra-precise advanced electronic devices for recording temperature readings in liquids and solids.They should be treated resistance thermometers, thermocouples, transmitters and detectors of the sensors equipped with relay mechanisms.Latest
temperature detectors are equipped with USB-interface, memory for storage and analysis of research-gunner laser designator.
Measuring water temperature
Each individual device for measuring the temperature of the water, cold and hot solutions characterized by a special principle of operation.There are universal devices are suitable for measuring performance of air.
Liquid Glass Thermometers
liquid meters are known as the most basic and accurate thermometers are available in angle and straight.But their scope - the analysis of the process equipment and utilities (measurements in pipelines).Devices suitable for values from -35 to +600 ° C, and as a sensing element is used more often than other mercury, and the reading is recorded on the scale.
Depending on the application and structural features distinguish medical devices, engineering, electrical contact, liquid, cane and others.
specific instrument for measuring the water temperature selected according to the margin of error in the measurements.
tools to determine the air temperature
first instrument for measuring temperature - a glass thermometer, an active element in a liquid which can be mercury, ethyl alcohol, toluene, and other substances.
Precision mercury gauges are cane and embedded glass scale.They are in demand in laboratory studies in various fields of production and medicine.Cane equipped with a thermometer thermally transparent graduated capillary tube, and the second kind of meters is characterized in that the division of the scale located behind it on a separate plate, and the whole mechanism is protected holster safety glass.
If you have a device called termosignalizatorom electrical contacts, and the sensitivity of the liquid inside the tank and capillary shows the current temperature of the surrounding space.
Features thermostats and sensors
In addition to these, there are other instruments for measuring temperature.For example, as the thermostats and sensors used stem dilatometers sensitive details from disparate ferro alloys, which are extended by heating at different values.
The same principle is characterized by another type of thermometer - Bimetallic, with inserted temperature-sensitive spring, welded with a pair of metal plates with different thermal expansion.During heating to the plate spring bends smaller termokoeffitsienta and largest bending outside temperature are desired.
electrothermometry
For remote fixing the thermal efficiency of the environment in the range of -15 to +125 ° C excellent non-contact temperature measuring instrument - aspiration electric thermometer.It includes a device connected by a cord meter and sensor.
sensitive element is a very fine copper wire gauge stranded helix strand in the frame.
What are the device for measuring body temperature
routinely measure body temperature thermometer.But today there are many other thermometers, differing in appearance and basic principles of action.
most common devices, which belongs to our thermometer work on thermal expansion of mercury, kerosene, alcohol, and others. Liquids.They are inexpensive, practical and sufficiently accurate, especially mercury, although the toxic contents in a fragile glass body carries with it some risk.
electronic or digital device for measuring body temperature indicates the desired value due to the built-in sensor, but it cost a lot more than the price of liquid "brothers."These thermometers contact.
infrared pyrometer do not require direct contact with the person acting remotely.The ultra-sensitive sensor for 2-15 seconds, reads the value of emission displays them.These non-contact temperature measuring devices are perfect for families with young children, situations with sleeping patients, and others. In addition, they are useful in everyday life in the cooking process, and the more powerful types - in the electricity industry, on construction sites, in metallurgy and other industries.
When necessary remote thermometer
Often there are situations when to measure the temperature of the contact method is not possible or is inconvenient.In such cases, you will need a thermometer - a device for remote temperature measurement, namely:
- when measuring indicators strongly heated objects or toxic environment;
- at difficult to access, with a small error can make measurements at a distance of tens of meters;
- when monitoring mechanisms in motion, and it would take a split second;
- in the diagnosis of electrical building when it is so convenient to meter remote scanning for multiple remote sites.
What devices can measure the temperature of the metal
in the metallurgical industry for the study of molten ferro alloys requires a strong instrument for measuring high temperatures.
is to be made already previously described pyrometer.They fix the heat radiation in the region, which characterizes the actual temperature of the metal.In difficult conditions, the heat super-high performance non-contact method is ideal.The LCD display shows the following information:
- actual temperature Fahrenheit and Celsius;
- boundary temperature;
- battery.
maximum accuracy of the measured variable can be achieved only when between the object and the remote device is not interference in the form of heat absorbing vapors or solids.If you need to make measurements of ferro alloys in the transport ladle or pouring, we should accept a condition that the temperature is less than the actual figure will be determined by calculations.
To avoid inaccuracies of this method, using another instrument for measuring the temperature of the metal, namely dummy black body.It is immersed in the melt and contains a tube with a soldered or open end of the hollow cone nozzle or a refractory metal.In any embodiment termoizmeritel should have an increased heat resistance, chemical resistance and excellent thermal conductivity to exhibit an extremely accurate.
Motor temperature measurement
Prolonged operation and periodic repairs of machinery require special equipment, which included - a device for measuring the temperature of the engine.These include thermocouples, thermistors and thermometers expansion.
Thermocouples - very comfortable and well-known among motorists instruments for measuring temperature surfaces, winding and the internal cavity of the engine.With these temperature sensors may be fixed data, even in hard to reach areas of the engine, in the grooves and the core.They represent two different metal insulated wire with soldered on one side ends that are placed in a particular point of measurement.The second ends are connected to a millivoltmeter, and thermometer, and the sum of the indices indicates the actual temperature value.
mercury and alcohol thermometers expansion are very convenient for the necessary measurements on the available areas: winding the exposed surface of the different parts, as well as outgoing (or incoming) of the engine air flow.Thermistors in the form of a copper wire coil is secured in several places of the engine, including their turn, fixed by taking readings and determining the average value.
secondary device used for temperature measurement
try to define what is an industrial secondary instrument for measuring temperature.In fact, this automatic device is an important addition to the main meter, trapping and converting recorded performance in human-readable form.It is necessary for precise control, signaling and timely regulation of temperature in those exceptional cases when there are deviations from the defined parameters of the working conditions.Separately isolated stationary and portable secondary appliances.
As a rule, the secondary temperature measurement instruments have a strong protective steel body and equipped with a graduated scale.Logging takes place according to the diagram recorded from thermocouples, strain gauges, thermometers, transducers and other devices.
considering different ways of presenting information, should be divided on the secondary recording devices and displays, single and multi-channel, single-band and dual function.In the presence of a signaling mechanism for these devices instantly it indicates an unacceptable change in temperature, different from the desired value.This helps maintain the logical flow of all reactions and processes in which they are involved.
With all the variety of devices that record temperature behavior of gases, liquids and solids should give serious consideration to the selection of the correct fit.The primary factors that should be taken into account are the permissible limits of temperature values, the maximum distance at which measurements can be carried out (sight), the accuracy.And, of course, take into account the scope of use of a particular type of thermometer.
