Lecture 4 - Level Flashcards
What are the two most simple and inexpensive methods of measuring level, Height, weight and volume?
A sight glass or a dipstick
Flaws involved with the dipstick and sight glass?
Dependent on skill of the user and not very accurate
Describe the operation of an electrically operated float gauge?
the float rises and falls with the liquid with this an angular movement of the slider along the potentiometer occurs. changing the potential difference.
Advantages of the electrically operated float gauges?
scale can be in terms of level, volume or mass.
electric signal allows for remote recording
Name a use for capacitance probes?
Airplane fuel quantities due to safety
Describe the Capacitance probe operation?
Two cylindrical tubes form a capacitor the gap between these is normally air but gets replaced by fuel due to the level increase causing a change in capacitance –> change in electrical output.
Ultrasonic Level indicator operation?
pulses of ultrasonic sound waves are emitted towards the liquid surface. The remainder of the pulse hits the base of the container and back up. The difference between the two is the liquid level.
How would you measure Weight or Force?
Load Cells
What are Load Cells?
4 strain gauges bonded to a load bearing element strin causing changes in resistance. the value of the potential difference can be directly linked to the load applied.
