Quote:
Originally Posted by Charles Stewart
Just want to understand and input will be really appreciated.
What is the relation between those ?
More grain of water per pound of dry air mean less air molecule in that pound of dry air.
I know that some area own more % oxygen than other (degree of pollution, tree, altitude, near ocean...) But do they serve the same goal in weather calculation or they have their own impact on calculation.
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PerformAIRE Weather systems calculate Density Altitude(Air Density) and is the only system that actually measures oxygen content, by use of an optional Oxygen sensor. The Oxygen percentage is influenced by the surrounding area (Pollution, Vegetation)
When we talk about Density Altitude it is a calculation based on the Temperature, Humidity, and Barometric Pressure alone in the air. Typically, we ASSUME a constant percentage of oxygen (20.90%) within that density. The only way to determine the actual percentage of oxygen and therefore the actual amount of oxygen per volume is by specifically measuring the oxygen level independently from the temp, hum and press.
An internal combustion engine does not burn "air density", it burns Oxygen with Fuel to create power. Knowing the actual amount of oxygen is very important and is the main factor a PerformAIRE weather station is providing to determine the performance.
Secondary, the amount of water in the air density also influences the performance of an engine. Generally, the more water in the air, the worse it is for performance. Not only is it displacing the amount of oxygen but it also can dilute the fuels energy potential.
Water grains is an ABSOLUTE calculation of the amount of water in the air. Unlike RELATIVE humidity (water % based on temperature), think of grains as the weight of the water in the air.
Without getting into too much detail, the PerformAIRE systems use Patented measurements and algorithms to determine not only the air density, the amount of oxygen, the water content, and how that all effects the engines performance.