Pressure Measurement

Question 1

defined as a ratio between a force and a unit area, perpendicular to the direction of that force, on which the force acts

one of the key of thermodynamic parameters

an intensive property

Answer 1

PRESSURE (that is what you are ✨)

Question 2

an occurence that is causing an object to move, either accelerating or decelerating

Answer 2

FORCE

Question 3

In a process environment, pressure is a key component to keeping a ______

Answer 3

system functional

Question 4

All fluid molecules will be in constant and random motion called _____________, due to which fluid at rest in a vessel, does exerts force on all the walls of the vessel, with which it is in contact

Answer 4

BROWNIAN MOTION

Question 5

2 ELEMENTS OF TOTAL PRESSURE OF A FLUID

Answer 5

1. Static Pressure

2. Dynamic Pressure

Question 6

defined as a pressure not associated with the fluid motion, but its state

it is the pressure which would be indicated by a gauge moving together with the fluid

Answer 6

STATIC PRESSURE

Question 7

a measurement of kinetic energy of a moving fluid and depends on its velocity and density

Answer 7

DYNAMIC PRESSURE

Question 8

the Italian Physicist who invented the barometer, with which he could evaluate the atmospheric pressure

Answer 8

Evangelista Torricelli

when: 1643

Question 9

Torricelli’s research about mercury columns pave way to the discovery of ____________

Answer 9

VACUUM

Question 10

This French Physicist used the barometer to show that the air pressure was smaller at the top of the mountains.

He also determined the weight of air and called it “pressure”

Answer 10

Blaise Pascal

Question 11

was granted the Bourdon Tube patent, used until today in relative pressure measurements

Answer 11

Eugéne Bourdon

When: 1849

Question 12

MOST COMMON TYPES OF PRESSURE MEASUREMENTS

Answer 12

• Absolute Pressure
• Differential Pressure
• Gauge Pressure

Question 13

it is measured with relation to perfect vacuum, namely the pressure difference at a given measurement point by the vacuum pressure (absolute zero)

Answer 13

ABSOLUTE PRESSURE

Question 14

the pressure difference measured between two points

Answer 14

DIFFERENTIAL PRESSURE

Question 15

When any point other than vacuum or atmosphere is used as reference, it means ___________

Answer 15

Differential Pressure

Question 16

measured in relation to the ambient pressure namely, in relation to the atmosphere

Answer 16

GAUGE PRESSURE

Question 17

a very simple device used to measure pressure

an instrument of differential pressure measurement, indicating the difference between two pressures by a shift in liquid column height

Answer 17

MANOMETERS

Question 18

He invented the manometer

Answer 18

Christian Huygens

when: 1661

Question 19

the ancient Greek words manometer is derived from

Answer 19

“manós” meaning thin or rare

“métron”

Question 20

states that the pressure at any point in a fluid at rest is equal, and its value is just the weight of the overlying fluid

Answer 20

Hydrostatic Equilibrium

Question 21

advantages ng manometer

Answer 21

• inexpensive
• no need for calibration
• no electrical output

Question 22

MANOMETER TYPES

Answer 22

1. U-Tube Manometers
2. Well Manometers
3. Raised-Well Manometers
4. Inclined Manometers

Question 23

consists of a a glass tube bent like the letter “U”

in this type of manometer, balancing a column of liquid is done by another column of same or other liquid

Answer 23

U-Tube Manometers

Question 24

the wall area is larger than the area of the tube. the rise in liquid level in the tube is considered while that in the well is ignored

Answer 24

Well Manometers / Cistern Manometers

Question 25

the vertical column limb of this manometer is inclined at an angle used for accurate measurement of small pressure similar to a well type manometer in construction

Answer 25

Raised Well Manometer / Inclined Manometer

Question 26

a type of manometer commonly used to check the blood pressure in humans

Answer 26

SPHYGMOMANOMETER

Question 27

the mercury reading on the pressure gauge when the pulse is first heard

Answer 27

Systolic Pressure Reading

Question 28

mercury reading on the pressure gage when the pulse can first no longer be heard

Answer 28

Diastolic Pressure Reading

Question 29

include the bellows, the diaphragms, and the bourdon tube. Each of these devices converts a fluid pressure into a force

Answer 29

Mechanical Pressure-Sensing Elements / Aneroid Gauges

Question 30

resemble an accordion constructed from metal instead of fabric they are thin-walled metallic cylinders, with deep convolutions, of which one end is sealed and the other end remains open. The closed end can move freely while the open end is fixed

Answer 30

BELLOWS

Question 31

nothing more than a thin disk of material which bows outward under the influence of a fluid pressure

Answer 31

DIAPHRAGMS

Question 32

Diaphragms with negligible spring effect used in conjunction with external mechanisms that produce the necessary restraining force to prevent damage from applied pressure

Answer 32

Slack Diaphragms

Question 33

made of spring-like metal alloys bent into a circular shape

Answer 33

Bourdon Tube

Question 34

a French watchmaker who invented the Bourdon tube in 1849

Answer 34

Eugéne Bourdon

Question 35

devices designed to measure fluid pressure and transmit that information via electrical signals such as the 4-20 mA analog standard or in digital form such as HART or FOUNDATION Fieldbus

Answer 35

Electronic Pressure Transmitters

Question 36

means “pressure-sensitive resistance” or a resistance that changes value with applied pressure

Answer 36

Piezoresistive

Question 37

a sensor whose resistance varies with applied applied force; it converts force pressure, tension, weight, etc., into a change in electrical resistance which can then be measured

Answer 37

STRAIN GAUGE

Question 38

an elastically deformable transducer that transforms an applied force or a mechanical displacement into a change in resistance

Answer 38

STRAIN GAUGE

Question 39

defined as the object‘s internal resisting forces

Answer 39

STRESS

Question 40

defined as the displacement and deformation that occurs

Answer 40

STRAIN

Question 41

APPLICATIONS OF THE STRAIN GAUGES

Answer 41

1. ) Measurement of Strain | 2. ) Measurement of other quantities

Question 42

here a change in capacitance is used to infer pressure measurement. also uses a change in electrical characteristics to infer pressure

Answer 42

Differential Capacitance Sensors

Question 43

a device that stores electrical charge it consists of two metal plates separated by an electrical insulator

Answer 43

CAPACITOR

Question 44

a classic example of a pressure instrument based on the differential capacitance sensor

Answer 44

Rosemount Model 1151

Question 45

allows the diaphragm to easily flex with applied pressure, transmitting process fluid pressure through the silicone fill fluid to the taut sensing diaphragm inside the differential capacitance cell

Answer 45

Concentric Corrugations

Question 46

senses the difference in pressure between two ports and outputs a signal representing that pressure in relation to a calibrated range one of the most common, and most useful, pressure measuring instruments in industry

Answer 46

Differential Pressure Transmitter