1. Muhajir Ab. Rahim School of Mechatronic Engineering, KUKUM
Pressure Sensor
Muhajir Ab. Rahim
School of Mechatronic Engineering,
KUKUM

2. Introduction P = F A Force per unit area, Gas, liquid
Unit, Pascal (N/m2), psi, torr,
atm, bar
P = F A

3. Type of Pressure
Static Pressure – fluid that is not moving in space (head pressure)
Dynamic Pressure – fluid in motion

4. Pressure Sensor
Relate to physical displacement (proportional to electrical signal)
Element used to convert pressure information into physical displacement (Diaphragm, Bellows, Bourdon Tube)
Solid-state device (IC technology based on small wafer silicon as sensing element)

5. Pressure Sensor
Based on the rate at which heat is conducted and radiated away from heated filament placed in low-pressure environment
Heat loss is proportional to the number of gas molecules per unit volume (filament temperature proportional to gas pressure)
Pirani gauge, thermocouple, ionization gauge

6. Example
A solid-state pressure sensor that outputs 25mV/kPa for a pressure variation of 0.0 to 25kPa will be used to measure the level of liquid with density 1.3 x 103kg/m3. What voltage output will be expected for level variations from 0 to 2 m?