3. Pressure, Displacement, Flow and Temperature Flashcards
1
Q
Resistive Sensor
Potentiometer
A
- produce linear potential output as f(displacement)
- 3 types: translational, single turn, multi turn
- movable arm that maintains electrical contact with R surface, wire coupled to arm-> forms voltage divider
- limitation due to wire spacing
2
Q
Resistive Sensor
Strain Gage
A
- when fine wire strained, change in depth/length (tension: decrease d, increase R)
- resulting strain gages can be used to measure small displacement
- delta R / R = G * delta L / L - G: gage factor
- G-metals > 1.6, G-semicond = (50-70)Gmetals
3
Q
Resistive Sensor
Bonded Gage
A
- modified strain gage
- R element is fine wire embedded in insulating backing material, cemented to pressure sensing element
- 3 types: Res-wire, foil type, helical wire
- bonded: entire strain on specimen transferred
4
Q
Resistive Sensor
Unbonded Gage
A
- unbonded -> not entire strain transferred -> not as effective
5
Q
Resistive Sensor
Semiconductor
A
- can be used as unbonded / bonded / integrated strain gage units
- pro: increased G, con: more T sens, non linear
- n or p type as substrate, opposite type diffused in
6
Q
Resistive Sensor
Implantable Gage
A
- add wireless data transmission
7
Q
Resistive sensors (6)
A
- potentiometer
- strain gage
- bonded gage
- unbonded gage
- semiconductor
- implantable gage
8
Q
Capacitive sensors (7)
A
- dynamic displacements
- membrane sensor
- comb structure
- medical capacitive pressure sensor
- intracranial pressure
- cardiac pressure
- intraocular pressure
9
Q
piezoelectric sensors
A
(something)
10
Q
electromagnetic flowmeter
A
- based no the principle that when a fluid containing electric charges flows in a magnetic field, a electromotive force is generated (lorenz force)
11
Q
temperature sensors (2)
A
- thermistors
- radiation thermometry
12
Q
Capacitive sensors
dynamic displacements
A
- capacitive sensor for measuring dynamic displacement changes
- applications: position, displacement, thickness, vibration
- pros: very linear outputs, stable w temp, high res measurements
