Temperature

Question 1

Static Air Temperature (SAT)

Answer 1

SAT is the temperature of the

undisturbed air through which the aircraft is about to fly

Question 2

Total Air Temperature (TAT)

Answer 2

TAT is the maximum temperature
attainable by the air when brought to rest adiabatically.
TAT= SAT*(1+0.2 M²)

Question 3

Ram Air Temperature (RAT)

Answer 3

The RAT is the measured air temperature

Question 4

RAM RISE

Answer 4

SAT - TAT

SAT - RAT

Question 5

Recovery Factor

Answer 5

The percentage of the Ram Rise sensed and recovered by a TAT probe.

Question 6

Heating error

Answer 6

Speed increases, the measured temperature exceeds that of the still air, the reason are kinetic (friction) and adiabatic (compression):
• Kinetic heating. Speed increases, more and more molecules of air per second
impact against surfaces of the probe. This causes a temperature rise due to friction.
• Adiabatic heating is the main contributor to the temperature rise effect
in the Remote Reading (or Total Head) thermometer. It is caused by a conversion of energy,
not a direct application of heat. For example, boiling a kettle is a direct application of heat,
whereas pumping a bicycle pump causes a rise in temperature without any input of heat
because pressure energy is converted into temperature energy. In temperature probe, the air >100 knots is brought
virtually to rest very rapidly. The energy of themoving air is released in the form of a temperature rise.