3A2 Chapter 12

Question 1

Bimetal thermometers consist of two thin metal strips bonded together. The metal strips welded together must have a small difference in their coefficient of expansion

A) true
B) false

Answer 1

B) false

Question 2

The coefficient of expansion of aluminum is higher than copper

A) true
B) false

Answer 2

A) true

Question 3

Iron and constantan can be used in a thermocouple to measure any temperature range

A) true
B) false

Answer 3

B) false

Question 4

The optical pyrometers operates on the principle that the colour of a hot object is a measure of its temperature

A) true
B) false

Answer 4

A) true

Question 5

Thermowells are _______

A) made of soft materials
B) used to protect the bulb from erosion, corrosion and impact
C) used in pipes only
D) not used with thermocouples
E) used in conjunction with a capillary tube

Answer 5

B) used to protect the bulb from erosion, corrosion and impact

Question 6

Bimetal thermometers are sometimes wound in the form of a helix to ______

A) increase the distance of the scale
B) decrease the temperature range
C) decrease the rotation of pointer
D) increase the accuracy of the temperature reading
E) increase the range of the scale

Answer 6

D) increase the accuracy of the temperature reading

Question 7

Filled thermal elements ______

A) always contain a liquid
B) may be filled with a liquid or gas
C) are always filled with mercury
D) are always completely filled with a gas
E) may be used wi the bimetal strips

Answer 7

B) may be filled with a liquid or gas

Question 8

Double bourdon tube gauge is used to measure vacuum only

A) true
B) false

Answer 8

B) false

Question 9

Belle was type elements are generally used to measure pressures below 350kPa

A) true
B) false

Answer 9

A) true

Question 10

Increasing the number of corrugations in a bellows type element ______

A) increases the travel of the bellows
B) decreases the travel of the bellows
C) reduces the pressure that bellows can be exposed to
D) increases the pressure that bellows can be exposed to
E) does not change the operation of the bellows

Answer 10

A) increases the travel of the bellows

Question 11

An absolute pressure gauge uses a/an _____ to sense pressure

A) diaphragm
B) bellows
C) bourdon tube
D) spiral bourdon tube
E) orifice plate

Answer 11

B) bellows

Question 12

A bourdon tube has an oval cross section, which is often shaped in the form of a “C”, having an arc span of about:

A) 360 degrees
B) 180 degrees
C) 120 degrees
D) 90 degrees
E) 270 degrees

Answer 12

E) 270 degrees

Question 13

An orifice plate is the most common form of restriction that is used in fl w measurement

A) true
B) false

Answer 13

A) true

Question 14

The pressure differential across an orifice plate is measured by a low pressure connection before the plate and a high pressure connection after the plate

A) true
B) false

Answer 14

B) false

Question 15

The orifice plate has the advantage over other types of metering restrictions because it _____

A) produces less permanent pressure drop
B) will handle 60% more flow
C) is easy to install and replace
D) more efficient than the other types
E) is permanently attached to the piping

Answer 15

C) is easy to install and replace

Question 16

When using a Venturi tube for flow measurement the high pressure connection is placed at the throat of the Venturi tube

A) true
B) false

Answer 16

B) false

Question 17

Venturi tubes will handle about 20% more flow than an orifice plate with the same pipe size and the same differential pressure

A) true
B) false

Answer 17

B) false

Question 18

The most undesirable feature of the orifice plate is the high permanent pressure loss that is created due to the turbulence in the flow across the orifice plate

A) true
B) false

Answer 18

A) true

Question 19

The vena contracts is the point where the ________

A) velocity is the lowest
B) fluid has the smallest cross sectional area
C) pressure begins to decrease
D) high pressure connection is made
E) low pressure connection is made

Answer 19

B) fluid has the smallest cross sectional area

Question 20

On the bellows type of indicating mechanism used in conjunction with orifice plate, the bellows are filled with what?

A) water
B) mercury
C) alcohol
D) methyl hydrate
E) ethylene glycol and water

Answer 20

E) ethylene glycol and water

Question 21

Rotary type positive displacement meters are independent of temperature, pressure and specific gravity

A) true
B) false

Answer 21

A) true

Question 22

Float operated level measurement devices are what?

A) direct type
B) indirect type
C) pressure sensing type
D) pneumatic type
E) temperature sensing type

Answer 22

A) direct type

Question 23

When diaphragms are used as sensing devices to measure level the low pressure side is filled with a sealing fluid

A) true
B) false

Answer 23

A) true

Question 24

A continuous air supply is provided to the differential pressure transmitter so that the level of a liquid in the tank can be converted into a constant proportional air signal

A) true
B) false

Answer 24

A) true