Air flow is a measurement of the amount of air per unit of time that flows through a measurement tool.
The amount of air can be measured by its volume or by its mass. Typically it is measured by volume, but for some applications it is necessary to measure it by mass. Air is a gas, meaning its volume can vary with temperature. The instrument that measures air flow is called an air flow meter. Measuring the airflow is necessary in many applications such as ventilation (to determine how much air is being replaced) and engines (to control the Air–fuel ratio).
Differential pressure, or DP or ∆p, is simply the difference between two applied pressures.A differential pressure gauge is a visual indicator, designed to measure and illustrate the difference between two pressure points within a process system. A differential pressure gauge simplifies the process by finding the difference between the points
The flue gases arising from the combustion contain CO2, oxide or soot particles, amongst other things. These pollute the environment, have a negative effect on the climate and conceal numerous health risks for human beings. That is why it is absolutely essential to design combustion processes in a more efficient way, to optimise thermal processes and above all to reduce emissions.