We explain what temperature is, how it is measured, and what scales are used. We also explain types of temperatures and their differences with heat.
What is temperature?
Temperature is a scalar quantity defined as the amount of kinetic energy of the particles in a gaseous, liquid, or solid mass. The greater the speed of the particles, the higher the temperature, and vice versa.
The measurement of temperature is related to the notion of cold (lower temperature) and heat (higher temperature), which can be perceived instinctively. In addition, temperature acts as a reference value for determining the normal temperature of the human body, providing information that can be used to assess health conditions. Heat is also used in chemical, industrial, and metallurgical processes. You must read about History of Gymnastics once.
Temperature Scales
There are different types of scales for measuring temperature. The most common are:
- The Celsius scale: Also known as the “Centigrade scale,” this is the most widely used scale, along with the Fahrenheit scale. On this scale, the freezing point of water is 0°C (zero degrees Celsius) and its boiling point is 100°C.
- The Fahrenheit scale: This is the measurement used in most English-speaking countries. On this scale, the freezing point of water occurs at 32°F (thirty-two degrees Fahrenheit) and its boiling point is 212°F.
- The Kelvin scale: This is the measurement most commonly used in science and establishes “absolute zero” as the zero point, which means that the object does not release any heat and is equivalent to -273.15°C (degrees Celsius).
- The Rankine scale: This is the measurement commonly used in the United States for thermodynamic temperature measurements and is defined by measuring degrees Fahrenheit above absolute zero, so it has no negative or subzero values.
How is temperature measured?
Temperature is measured using thermometric magnitudes, that is, different units that represent temperature on different scales. This is achieved by using a device called a “thermometer,” of which there are several types depending on the phenomenon being measured, for example:
- Expansion and contraction: There are thermometers to measure gases (constant pressure gas thermometer), liquids (mercury thermometer), and solids (liquid column or bimetallic thermometer), which are elements that expand at high temperatures or contract at low temperatures. Electrical resistance variation: Electrical resistance, that is, the flow of electrons moving through a conductive material, varies depending on the temperature they reach. Electrical resistance thermometers are used to measure resistance, such as sensors (based on a resistance capable of transforming the electrical variation into a temperature variation) and thermoelectric thermometers (which generate a driving force).
- Thermal radiation thermometer: Radiation phenomena emitted in the industrial sector can be measured using temperature sensors such as infrared pyrometers (for measuring very low refrigeration temperatures) and optical pyrometers (for measuring high temperatures in furnaces and melting metals).
- Thermoelectric potential: The union of two different metals subjected to different temperatures generates an electromotive force, which is converted into an electric potential and measured in volts. Maybe you should definitely read about Gymnastics once.
Types of Temperature
There are different types of temperature, and therefore, they are measured with different tools, such as:
- Ambient temperature: This is the temperature that can be recorded in the spaces where humans move. It is measured using an ambient thermometer that uses Celsius or Fahrenheit values.
- Body temperature: This is body temperature. 36°C is considered normal for humans, and if the temperature exceeds 37°C (or 98°F), the individual is considered to have a fever.
Other types of temperature measurement allow for calculating the thermal sensation, for example:
- Dry temperature: This is the ambient temperature, without taking into account ambient heat radiation and humidity. It is measured with a bulb thermometer painted bright white to avoid absorbing radiation.
- Radiant temperature: This is the temperature of surfaces and walls in an enclosed space and is measured using a bulb thermometer. Humidity: This is the temperature measured by a thermometer placed in the shade, with its bulb wrapped in damp cotton and placed under a draft. Through this system, the water in the cotton evaporates and heat is absorbed, generating a decrease in the temperature recorded by the thermometer relative to the ambient temperature. This results in a measurement of air humidity, which is used to measure wind chill.
Difference between heat and temperature
Although heat and temperature are closely related concepts, they are not the same. Some differences are:
- Meaning: Heat is thermal energy that should be understood as heat transfer, which occurs when there is a temperature difference between two bodies. This transfer always has a direction and is from the body with the higher temperature to the one with the lower temperature. Temperature, on the other hand, is a measure of the average kinetic energy of the molecules that make up the matter.
- Symbol: Heat is represented by the letter Q and temperature by the letter T.
- Effect: The transfer of heat to a body increases its temperature. Temperature is the average kinetic energy of the particles in a body, which increases if heat is applied to it.
- Transmission: Heat is transmitted from one substance to another and can spread by conduction, convection, or radiation. The temperature level reached depends on the type of heat propagation.
- Measurement object: Heat is measured with a calorimeter, and temperature is measured with a thermometer.
- Unit of measurement: Heat is measured in joules, calories, and kilocalories. Temperature is measured in degrees Kelvin (k), Celsius (C), or Fahrenheit (F).
Examples of Temperature
Some examples of temperatures are:
- The temperature of a running car engine is 85°C.
- The ambient temperature, considered comfortable, is between 20° and 25°C.
- The temperature of a pizza oven is 180°C.
- The temperature of boiling water is 100°C.
- The average body temperature is 36.5°C.
- The temperature at which water solidifies to the point of turning into ice is 0°C.
- This temperature is controlled by a voltage regulator located inside an electrical device, preventing it from overheating or damaging the equipment.
References
All the information we offer is supported by authoritative and up-to-date bibliographic sources, ensuring reliable content in line with our editorial principles.
- “Concept of Temperature” in Physics Lab.
- “Temperature Scales” in How to Study.
- “The 7 Differences between Heat and Temperature” in Psychology and Mind.
- “Temperature Scales” in Thales.
- “Engine Temperature: How the System Works” in Guioteca.
