thermometers
It is an instrument capable of measuring the temperature of bodies.
Types of thermometers
liquid thermometer
One of the most used thermometers is mercury. Mercury is used because it can be obtained in an excellent state of purity, it is opaque with a color contrasting with the glass that surrounds it, facilitating readings, it expands or contracts uniformly as a function of temperature, and in the liquid state it has a wide thermal range whose extremes are –38°C and +360°C.
pressure thermometer
This type of thermometer uses the principle of expansion of saturated steam in a confined space, consisting of a bourdon tube, bellows or diaphragm, capillary tube and bulb, which undergoes internal pressure variation as a function of temperature, producing a mechanical effect on a set. of mechanical gears that will indicate temperature values on a defined scale.
thermocouple
In 1821, the German physicist Thomas Seebeck discovered that, by joining the ends of two wires of different metals (iron and copper, for example), and keeping the junctions at different temperatures, an electric current appeared through the wires.
electronic thermometers
Electronic thermometers base their temperature reading and indication systems on variations in some thermoelectric properties of materials used as sensors.
These properties, characteristics, undergo changes as temperature changes occur in the substance for which the temperature value is desired. This change is converted through electrical signals into digital logic and indicated through displays.
Note: Temperature is the measure of the degree of thermal agitation of the molecules of a body, it does not depend on the number of molecules in movement, but on the intensity of this movement. The faster the movement of molecules, the “hotter” the body appears and the slower the movement of molecules, the “cold” the body appears.
Thermometry aims to measure the degree of thermal agitation of the molecules of a given substance according to the amount of heat received or given off when it undergoes a physical or chemical transformation.
