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Question 1

What is an ultrasonic transducer used for?

Answer 1

Measuring the water level to read flow

Question 2

How does the ultrasonic transducer measure flow?

Answer 2

Sends pulse down, detects echo back. measures level as a fcn of time

Question 3

Why does temp matter with ultrasonic?

Answer 3

Need air temp to calculate speed of sound

Question 4

Advantages to ultrasonic?

Answer 4

non-contact, easy installation, minimal maintenance

Question 5

Disadvantages to ultrasonic?

Answer 5

1) limitations on how high to put with the dead band 2) beam angle impacted by narrow walls, false echos 3) Wind, steam, foam, and turbulence can impact reading: steam=reflect echo, foam=absorb echo, turbulence=reduce sig strength, wind=interfere with sound wave

Question 6

How does a bubbler work?

Answer 6

Pump pushes out a bubble, transducer measures pressure to push out 1 bubble

Question 7

Advantages to a bubbler? (5)

Answer 7

1) good for small channels 2) not impacted by wind, steam, foam, temp, turbulence 3) No electronics in flow stream 4) Easy, cheap 5) accurate

Question 8

Disadvantages to bubblers? (3)

Answer 8

1) restrictions or sediment can impairs line (cause a false high reading) 2) Needs higher maintenance 3) Greater power consumption

Question 9

How does a submerged pressure probe work?

Answer 9

In flow, measures the pressure

Question 10

Advantages of pressure probes? (3)

Answer 10

good in small channels 2) no impact from steam, wind, foam, turbulence 3) Senses pressure through silt/sand

Question 11

What is a weir?

Answer 11

Any dam built accross open channel where water flows over

Question 12

Disadvantages to submerged pressure probe? (4)

Answer 12

Chemistry can impact it 2) flowing debris, block channel 3) Higher maintenance 4) Temps can impact

Question 13

What is a flume?

Answer 13

Specially made channel to accelerate flow, create relation between water level and water flow

Question 14

What do you need to accruately measure open channel flow? (2 things)

Answer 14

A flume/weir, level sensor, and sometimes a flowmeter if cant directly read from the level sensor

Question 15

Why would you put in a weir in the first place?

Answer 15

control the flow of water and level

Question 16

What is the issue with putting level sensor right at the crest of a weir?

Answer 16

Drawdown effect closest to weir. False low reading. Place upstream

Question 17

Difference between pipe/closed conduit flow and open channel flow?

Answer 17

Open channel propelled by gravity, for closed channel, pressure impacts flow

Question 17

If flow is going through a closed pipe but it doesnt fill it, is that pipe flow or open channel?

Answer 17

Open channel

Question 18

What is the most common type of flume for industrial discharge?

Answer 18

Parshall

Question 18

Where read depth for a parshall flume?

Answer 18

At the converging section upstream, NOT throat and NOT diverging section

Question 19

What relationship does a flume create…..

Answer 19

Relationship between the fluid level of flume and the flow of the water created

Question 20

Where should we take the depth reading for a Parshall flume? (converging seciton, throat, diverging)?

Answer 20

Converging section

Question 20

Where measure depth for small/medium parshall flumes?

Answer 20

For small and medium sized Parshall flumes, Ha is located 2/3 of the distance upstream of the beginning of the throat

Question 20

Which sections of parshall flume have a flat section? (converging, throat, diverging)

Answer 20

Converging

Question 21

Can you measure at multiple points on a palmer bowlus?

Answer 21

Yes

Question 22

Where can you measure on palmer bowlus?

Answer 22

Anywhere upstream basically

Question 23

Where does sub and supercritical flow happen in parshall flume?

Answer 23

Sub before and in converging section, super in throat

Question 24

What are supercritical, critical, and subcritical flow?

Answer 24

Types of open channel flow