Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Measuring > Test 3 > Flashcards

Test 3 Flashcards

1
Q

What is an integral orifice meter?

A

Small orifice plate mounted internally in a dp transmitter or externally on transmitter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are integral flow meters typically used for?

A
  • Air flow
  • Gas flow
  • Small gas flows
  • Chemical additions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Requirements for fluid running through an integral orifice meter?

A
  • Clean
  • Free of suspended solids
  • At moderate temperature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a venturi tube?

A
  • Convergent/Divergent shape
  • Dif pres comes from smallest and largest sections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Advantages of a venturi tube?

A
  • Very small process pressure loss
  • Available for large pipe diameters
  • Accurate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Disadvantages of a venturi tube?

A
  • Expensive
  • Requires long section of straight pipe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a (conventional) pitot tube?

A

A tube with a hole pointing upstream to measure the impact pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

If the pitot tube is used in a pipe under pressure…

A
  • Second hole
  • Downstream
  • Static pressure
  • Differential pressure

A second hole will point downstream to measure the static pressure so that a differential pressure can be taken

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Uses of (conventional) pitot tube?

A
  • Large water lines
  • Open channel measurement (OCM)
  • Air speed
  • Water speed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Advantages of (conventional) pitot tube?

A
  • Convenient insertion in flow lines
  • Measurement of large flows
  • Little to no restriction in process line
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Disadvantages of (conventional) pitot tube?

A
  • Plugs easily
  • Accuracy issues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is an annubar pitot tube?

A

Same principle as conventional but has holes across flow to give an average -> more accurate output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When are area averaging pitot tubes used?

A
  • In large duct work/where there are large flows with low pressure gasses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Principle of operation of flow meter?

A
  • Nozzle -> Restriction -> Dif Pres prop to flow rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are flow nozzles mainly used for?

A
  • Steam flow applications
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Advantages of flow nozzle?

A
  • Less pressure loss than an orifice plate
  • Can be used on high pressure/high temperature applications
  • Very little wear caused by erosion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Disadvantages of flow nozzle?

A
  • Difficult to install/remove (wider than opening it goes in)
  • Expensive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Difference between segmental wedge and orifice applications?

A

A segmental wedge is more gradual than orifice applications

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Primary use for segmental wedge?

A

Slurry applications

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Advantage of segmental wedge?

A

Can measure low velocity/high viscous fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Disadvantage of segmental wedge?

A

Low accuracy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Variable area type rotameter principle of operation?

A
  • As flow increases, the displacer moves up the tube -> allowing more area for the flow
  • Differential pressure remains constant and the orifice size changes
  • Can be used to measure flow by installing directly in the line
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Main parts of a variable area type rotameter?

A
  • Tapered
  • Displacer (float)
  • Scale for reading
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Principle of operation of a bypass meter?

A
  • Can be mounted across a restriction -> allows a small rotameter to measure a large flow in a large pipe
  • Can have a remote displacer for an external indication or be connected to some device to produce an output
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Displacer notes:

A
  • Sometimes called “floats”
  • Various designs (shapes) for a wide range of flow rates
  • Gas/air flow typically uses a ball-shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Rotameter disadvantages?

A
  • Must use clean liquid (unless using remote displacer -> still should be, but doesn’t have to be)
  • Fragile
  • Cannot freeze
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What type of meter is a nutating disk?

A

Positive displacement type meter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What type of meter is a diaphragm meter?

A

Positive displacement type meter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What WAS a common use for nutating disks?

A

Residential water use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Nutating disk principle of operation?

A
  • Disk wobbles (not spins) as flow passes through meter
  • Disk is connected to a gear train that turns an integrator or counter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Disadvantage of nutating disk?

A

Cannot be used with:
- Corrosive chemicals
- Suspended solids
- High pressure (applications)
- High temperature (applications)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Diaphragm meter principle of operation?

A

Works on the principle of diaphragm expansion and sliding disks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Diaphragm meters are used for…

A

Gas flow applications only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Diaphragm meter advantages?

A
  • Very little maintenance
  • Accurate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Diaphragm meter common use?

A

Residential natural gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Turbine meter principle of operation?

A

Flow drives a turbine that can be connected to an integrator or electronic speed pickup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Turbine meter disadvantages?

A

Can be expensive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Turbine meter advantages?

A
  • Can be used for high-pressure application
  • Specially designed units can be used to measure mass flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Target flow meter principle of operation?

A
  • Process fluid hits disk. Impact force is transmitted through the force bar to the sensor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Target flow meters are often used as…

A

A flow switch for alarm purposes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Target flow meter advantages?

A
  • Can be electric or pneumatic
  • Compact
  • Easily installed
42
Q

Target flow meter disadvantage?

A
  • Mechanical parts
43
Q

Paddle wheel principle of operation?

A

Rotation of the paddle wheel can be detected magnetically or optically

44
Q

Paddle wheel advantages?

A
  • Cheap
45
Q

Paddle wheel disadvantages?

A
  • Low accuracy
46
Q

Sight flow indicator…

A

Provides a window into a pipe system when visualization of the process is necessary

47
Q

A flow switch…

A

Is used to determine if the flow rate is above or below a certain value

48
Q

A magnetic flow meter is…

A

an instrument that measures flow based on the principles of Faraday’s law (electromagnetic induction)

49
Q

Magnetic flow meter principle of operation 1?

A
  • A magnetic coil sets up a magnetic field. This field is powered either by an AC voltage or pulsating DC voltage (more common due to the ability to eliminate static nouse continually)
50
Q

Induced voltage formula?

A

E=kBD*V

51
Q

A magmeter contains:

A
  • Magnetic coils
  • Electrodes (must contact the fluid to measure induced voltage)
  • Straight length of non-magnetic stainless-steel pipe
  • Insulated inside with a non-conductive material (Teflon, ceramic, rubber, etc.)
52
Q

In a magmeter, fluid must be…

A

A suitable conductor

53
Q

Magmeters are used to measure…

A
  • Slurries
  • Corrosive chemicals
  • Water
  • etc.
54
Q

Magmeters CANNOT measure…

A
  • Gas/steamm
  • High temp
  • High pres
55
Q

Vortex flowmeter principle of operation 1:

A
  • Fluid vortices or eddies are formed as flowing fluid passes a bluff body (wedge shaped obstruction) located in the stream
56
Q

Vortex flowmeter can be…

A

Very accurate

57
Q

Vortex flowmeters are not affected by…

A
  • Viscosity
  • Density
  • Pressure
  • Temperature
58
Q

Vortex flowmeters can measure the flow of…

A
  • Liquids
  • Gases
  • Steams
59
Q

Vortex swirlmeter principle of operation 1:

A
  • Blades at the inlet to the meter cause the process to swirl
60
Q

Ultrasonic flow meter (transit time type) principle of operation 1:

A
  • This type of flowmeter has two transmitter-receiver (they do both) units mounted on an angle to the flow
61
Q

Ultrasonic flow meter (doppler type) principle of operation 1:

A
  • Doppler effect
62
Q

Ultrasonic flow meter (doppler type) disadvantages?

A
  • Accuracy varies
  • Calibration is difficult
  • Must have suspended solids in the flow
63
Q

Ultrasonic flow meter (doppler type) is often used as a…

A

portable unit for flow verification

64
Q

Mass flow measurement is…

A

a measure of the weight of solution rather than just the volume. Measurement is given in pounds or kilograms rather than liters or gallons

65
Q

Mass flow measurement can be made by measuring the…

A

density and flow separately and computing the mass flow from these values

66
Q

Mass flow of slurry will go to…

A

a math unit

67
Q

Mass flow of slurry uses…

A

flow and density

68
Q

The mass flow of a slurry would use a….to measure flow

A

Magnetic flow meter

69
Q

The mass flow of a slurry would use a….to measure density

A

Radiation type transmitter

70
Q

Mass flow of air is measured with…

A
  • Venturi Tube
  • Orifiace plate
  • Etc.
71
Q

What all is measured to get the mass flow of air?

A
  • Pressure
  • Flow
  • Temperature
72
Q

What changes the volume/density of air?

A
  • Temperature
  • Pressure
73
Q

What dpe is best for duct work?

A

Pitot tubes

74
Q

What element, despite being the best for duct work, should not be used on mass-flow?

A

Pitot tubes

75
Q

Principle of operation for coriolis mass flow meter 1?

A
  • A C-Shaped tube is vibrated at its resonant
76
Q

What is the phase shift?

A

The difference in time/location sensors pick up during oscillations

77
Q

Coriolis mass flow meter: the oscillating frequency is a direct measure of…

A

density

78
Q

Magnetic flow meter principle of operation 2?

A
  • The fluid in the pipe, running between the magnets, acts as a conductor, cutting the lines of force of the magnetic field
79
Q

Magnetic flow meter principle of operation 3?

A
  • As the lines of force are cut, a voltage is induced. This voltage is picked up by electrodes embedded in the walls of the pipe
80
Q

Magnetic flow meter principle of operation 4?

A
  • The induced voltage picked up by the electrodes is proportional to the strength of the magnetic field and the velocity of the conductor
81
Q

Principle of operation for coriolis mass flow meter 2?

A
  • A driving mechanism is used to cause the tubes to oscillate
82
Q

Principle of operation for coriolis mass flow meter 3?

A
  • The material passing through the interior of the pipe will cause the pipe to twist
83
Q

Principle of operation for coriolis mass flow meter 4?

A
  • This twisting is proportional to the value of the mass-flow
84
Q

Principle of operation for coriolis mass flow meter 5?

A
  • The twisting can be measured with optical or magnetic sensors
85
Q

Principle of operation for coriolis mass flow meter 6?

A
  • Mass-flow is determined by measuring the phase shift between the two sensor positions
86
Q

Vortex flowmeter principle of operation 2:

A
  • The frequency of the shedding of these vortices is proportional to the fluid velocity
87
Q

Vortex flowmeter principle of operation 3:

A
  • The frequency is picked up by sensitive sensors located in the bluff body
88
Q

Vortex flowmeter principle of operation 5:

A
  • Various types of detector technologies can be used (E.g. strain gauge, piezoelectric, capacitance)
89
Q

Vortex swirlmeter principle of operation 2:

A
  • The body or bore of the meter body contracts -> fluid accelerates
90
Q

Vortex swirlmeter principle of operation 3:

A
  • As the swirl enters the throat of the meter, it takes on a helical motion that increases as the body enlarges
91
Q

Vortex swirlmeter principle of operation 4:

A
  • The velocity of the fluid in the vortex is faster than the surrounding fluid
92
Q

Vortex swirlmeter principle of operation 5:

A
  • As each vortex passes the sensor, there is a change in fluid velocity
93
Q

Vortex swirlmeter principle of operation 6:

A
  • The frequency at which the velocity change occurs is proportional to the volumetric flow rate
94
Q

Ultrasonic flow meter (doppler type) principle of operation 2:

A
  • A transmitter reciever unit is placed on the outside of a pipe and a sound wave is transmitted into the flow
95
Q

Ultrasonic flow meter (doppler type) principle of operation 3:

A
  • The sound wave is reflected off air bubble and/or particles within the flow back to the receiver
96
Q

Ultrasonic flow meter (doppler type) principle of operation 4:

A
  • A frequency shift is measured that is proportional to the velocity -> the volumetric flow rate
97
Q

Ultrasonic flow meter (transit time type) principle of operation 2:

A
  • Sound waves are sent from one transmitter-receiver unit to the other and back again
98
Q

Ultrasonic flow meter (transit time type) principle of operation 3:

A
  • In one direction, the process flow will aid the sound waves and the other direction will oppose the sound waves
99
Q

Ultrasonic flow meter (transit time type) principle of operation 4:

A
  • The difference in time between upstream and downstream signals is directly proportional to the velocity of the flow therefore the flow rate
100
Q

Rotameter advantages?

A
  • Simple
  • Inexpensive
  • Can measure low flow rates accurately
  • Can be used to measure corrosive, clear liquids and gases
  • Can be supplied with a needle valve to adjust the flow rate

Measuring (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions