I'm trying to get a deep understanding of the term: Density Altitude.
So I have read the explanations in my instruction book, and online articles. One source explained it differently then the other which confused me.
Wikipedia defines Density Altitude as:
The density altitude is the altitude relative to standard atmospheric conditions at which the air density would be equal to the indicated air density at the place of observation. In other words, the density altitude is the air density given as a height above mean sea level..".
So if I would believe Wikipedia then I could look at the ISA table to find the altitude by using the pressure.
Here is an ISA table:
My instruction book (Aerodynamica, prestatieleer en vliegtuigtechniek by Bas Vrijhof on page 112, written in Dutch) claims this:
in de ISA is de dichtheidshoogte altijd gelijk aan de drukhoogte
Translated to English: in the ISA the density altitude is equal to the pressure altitude.
So, let's say I'm flying in an aircraft, the pressure is "22.22 Hg", and the outside air temperature is -0.9°C. The altitude in the ISA would be 8000 ft. The Density Altitude would also be 8000 ft.
Skybrary defines Density Altitude as:
Density altitude is pressure altitude corrected for temperature.
This explanation contradicts with the Wikipedia explanation:
the air density would be equal to the indicated air density at the place of observation
On another wikipedia article I found this:
De relatie tussen temperatuur, hoogte en luchtdichtheid kan worden uitgedrukt in density altitude.
Translated to English: The relationship between temperature, altitude and air density can be represented as density altitude. Link: https://nl.wikipedia.org/wiki/Opstijgen#Benodigde_snelheid
So in short, each source explains Density Altitude in their own manner, some contradict the other which confuse me.
So my question is:
What is Density Altitude?