Thermometer A tool for measuring the temperature. Laser Digital Thermometer Laser is one of the advanced types of thermometers. The thermometer consists of two main parts. The first part can be called the temperature sensor, which plays a role in ordinary models, ie a mercury bubble thermometer containing mercury, and in a digital laser thermometer, which is also called a laser infrared thermometer. A digital sensor does the job. The second basic part of a thermometer is its calibration and calibration. Calibration and calibration means the display and transfer of measured data to the user with full accuracy, which is calibrated in a mercury thermometer board and in the laser thermometer the screen is responsible for this task. has it.
Types of thermometers:
The thermometer is made of a very narrow glass tube with a chamber at the end filled with mercury or alcohol. There is a complete vacuum inside the mercury thermometer tube. The heating and cooling of the tank causes the liquid inside the tank to heat and cool, and finally causes the liquid to go up and down inside the glass tank, by observing the liquid level inside the thermometer tube and reading the number written on the glass body. It is determined at that moment.
In addition to the normal air temperature, it is often necessary to measure and stabilize the maximum temperature that has occurred during a certain period, such as a day and night. For this purpose, the maximum thermometer is used.
- Minimum Thermometer
Minimum thermometers are used to stabilize the lowest temperature that has occurred in a given period. Minimum thermometers are similar to conventional thermometers, except that the liquid in the tank of this type of thermometer uses thinner liquids such as alcohol instead of mercury.
- Min-Max Thermometer
This compound thermometer, known as the Six thermometer, was made by the Italian scientist James Six and is made of twoThermometerMinimum and maximum, this thermometer is made of a U-shaped glass tube with closed ends.
- Gas thermometer
- Digital and electric thermometer
These types of thermometers work based on electrical properties that are widely used in various industries and are able to measure from low temperatures to very high temperatures. These thermometers are mainly in the types of electrical resistance and Thermocouple are made.
– Electric resistance thermometer
An electrical resistance thermometer is a long, thin wire that is usually wrapped around a thin frame to prevent pressure from changing the length of the wire due to its contraction as it cools. This thermometer can be mounted on the surface of an object whose temperature is intended to be measured or placed in a hole created for this purpose.
A thermistor is a semiconductor device that, unlike metals, has a negative resistance temperature coefficient. In addition, its resistance changes exponentially with temperature.
Thermocouple thermometer or in other words thermometer is a thermocouple thermometer based on a thermoelectric phenomenon. According to this phenomenon, if we connect the two ends of heterogeneous thin conductor wires (for example, copper and iron) and connect the two ends of the wires to one milliampere meter, by heating the common point of connection of the two The wire is in a small electric current circuit and there is a potential difference that the amount of this current, in addition to the resistance of the circuit and the material of the wires, also depends on the temperature applied to the joint of the two.
– Quartz crystal thermometer
The use of quartz crystal sensors is a new and very accurate method for measuring temperature based on the ratio of the change frequency of the resonant quartz crystal to the change in temperature. These sensors consist of a quartz crystal cut that, when cut from the right angle of the crystal, establishes a linear relationship between the resonant frequency and temperature. This perfectly linear relationship is used as a convenient and accurate scale for measuring temperature.
Thermometer | What is a laser thermometer?
All objects have infrared or thermal radiation. Laser thermometers absorb infrared radiation based on the object, like cameras, through their lens or internal mirror, then pass this infrared wave through a filter to focus the radiation on the detector, which can be a sensitive thermometer or electronic sensor, and output it. Shows this radiation as temperature. Using this method, the temperature of objects can be measured non-contact and remotely. This feature has made laser thermometers known as non-contact thermometers. In a laser thermometer, the collected radiation is analyzed according to Planck’s law of radiation.
As mentioned at the beginning, all objects have thermal radiation, which is mainly in the infrared range, but as the temperature rises to 700 ° C, the color changes from orange to yellow, and finally a bright white heat appears. The use of laser thermometers and their manufacturing technology makes it possible to measure temperatures up to -50 and even lower. The disadvantages of this method are the dependence of the rays emitted from the body with the surface properties and the degree of saturation of the body.
Laser infrared thermometer
The laser thermometer is basically the same as the infrared thermometer, which has a laser indicator to help point the device lens towards the heat source, hence the laser thermometer is sometimes referred to asRifle thermometer Also read. The laser thermometer may be a few meters away from the target under test because it is non-contact, so it should have a direct line of sight with the object. Dust, water vapor or carbon dioxide in the air may prevent rays from reaching the lens. In some cases, temperature measurement by non-contact thermometer uses optical fiber to transmit rays, which can be measured with special calculations.
How a laser thermometer works:
Temperature measurement methods can be divided into contact and non-contact. In the contact method, call onesensorWhich can be a thermocouple thermometer or a resistance thermometer (PT100) is a temperature measurement agent. It is also used as a temperature measuring instrument. Other instruments of this family are thermometersThermometerIt is a gas.