Thermal

Question 1

NTC and PTC

Answer 1

They are Negative and Positive Temperature Coefficients -> That means that, respectively, the resistance of the silicon decreases or increases as the temperature increases
PTC are used as current limitters

Question 2

Using a PN junction as a temperature sensor

Answer 2

• range (50º to 150º) because this is where the resistivity of the silicon increases with temperature
  When a silicon diode is used for temperature measurement, usually
  the forward voltage as a function of the temperature for a constant small
  forward current is measured. figure 4-19 shows such a dependency as measured by Russian authors [4.19]. Between 20K and 300K a linear behaviour is measured, whereas at 20K a sharp rise of the junction voltage is observed while the ionization of the impurity atoms at this temperature is no longer complete.

Question 3

Effects that determine the magnitude of the Seebeck coefficient

Answer 3

Change in the fermi level 
Charge carrier concentration gradient changes
Bandgap changes
Diffusing - coefficient changes
Thermodiffusion 
Phonon drag 
Charge accumulation

Question 4

How acceleration can be measured using thermal measurement techniques

Answer 4

Using several thermal flow sensors in tandem maybe

Question 5

Thermal flow sensor

Answer 5

based on the heat transfer coefficient from a heated sensor to a the fluid (boundary layer method
The boundary layer upstream is lighter than the boundary layer downstream; There will be a temperature difference between the layer upstream and the layer downstream, so, this way, you cam measure how fast the fluid is moing

Question 6

Vacuum sensor

Answer 6

Is based on the premise that the heat transfer coefficient between 2 surfaces is proportional to the number of molecules
Pirani gauge: electrically heated filament placed in the vaccum space

Question 7

IR sensor

Answer 7

based on a tandem sensor
IR is radiated to a cantilever and this cantilever is then bent or strained and this strain (deflected) and this temperature difference that is formed
High seebeck coefficient values

Question 8

Peltier effect

Answer 8

Release or absorption of heat at the junction of 2 dissimilar conductors, when there is passing of a current through that junction