A. Liquid
B. Mechanical
Manometers - pressure measuring devices
Transducer - a device that changes energy from one form to another
e.g. mercury manometer, U-tube manometer
Principle: the force of gravity on the molecules of a liquid gives rise to pressure that depends on the height of the liquid above the point of measurement
Sensitivity can be increased by wide bore tubing or tilting the tube
Coiled tube with flattened cross-section. When pressure within the tube increases, it uncoils slightly.
(without liquid)
Pressure changes cause movement of bellows
--> lever mechanism detects and magnifies changes
--> movement drives the pointer across a calibrated scale
Increased pressure causes movement of diaphragm, which is detected in 3 different ways
A. Strain gauges
When wire or silicon crystal is stretched or compressed, the electrical resistance changes
* stretched wire --> higher R
Two types:
B. Others
About | |
Created | 20050531 |
Reviewed | 20050601 |