What Does calorimetry Mean
Calorimetry is known as the area of physics focused on the techniques and resources to measure heat . It is also called calorimetry to measure the heat that, in a biological, chemical or physical process, is absorbed or released.
The heat
Before moving on, it is important to highlight that heat is an energy that passes from one body to another. These bodies, due to the action of heat, can register changes of state and expand.
All the energy in the body is converted into heat
One of the most important concepts related to heat and bodies is transfer , a process belonging to the realm of physics that is described as the propagation of heat by different means. Precisely, calorimetry is dedicated to measuring the alterations that occur in state variables to find out the heat transfer associated with them, taking into account the reasons that cause them and also imposing certain well-defined restrictions.
Calorimeter
Calorimetry uses a device called a calorimeter to measure heat. What the calorimeter does is record the amount of heat that a body receives or supplies, thus determining its specific heat and the heat it captures or releases.
Calorimeters are usually closed, insulated containers that contain water, a thermometer, and a stirrer. By resorting to a heat source and stirring the water until equilibrium is achieved, the increase in temperature is measured by the thermometer. Through calculations, it is possible to know the heat released, the heat absorbed, etc.
Direct calorimetry
As we will see below, this concept can be studied from two different perspectives according to the measurement method. In the first place we can talk about direct calorimetry , which opens the doors to the measurement of the energy that the human body generates throughout the two main phases of its day to day: rest and effort .
Its basis is found in the statement that all the energy produced by our body is converted into work or heat , a constant process that keeps us in balance and is essential for our development.
The direct term tells us that the measurement has to be carried out in unnatural conditions , since the person must be in a hood capable of measuring the temperature with great precision and determining the amount of calories burned at all times. This would not be possible, for example, in full practice of a sport.
In addition, not only can it not be applied to a daily or normal situation, but it has a very high cost and cannot be used in any clinic. In other words, this type of calorimetry is typical of the scientific field of research.
Heat spreads by different means
Indirect calorimetry
The indirect calorimetry , in this context, is the most accessible in economic and infrastructure to direct alternative. To avoid the demands of the other type of measurement , it relies on gas analysis following certain mathematical parameters. The test performed in this case is stress testing.
In more technical terms, this kind of calorimetry measures oxygen consumption and / or the production of carbon dioxide and nitrogen waste to estimate the heat produced by a living being. There are different ways of collecting gases for the development of indirect calorimetry.
A doctor, for example, may instruct a person to use a metabolic meter to track their CO2 production and O2 consumption while breathing spontaneously. Thus it is possible to study eventual metabolic diseases and other disorders.