Ch. 12 Flashcards
1
Q
- The coefficient of expansion of aluminum is higher than copper.
a. True
b. False
A
a. True
2
Q
- 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
A
b. False
3
Q
- The optical pyrometer operates on the principle that the color of a hot object is a measure of its temperature.
a. True
b. False
A
a. True
4
Q
- Iron and constantan can be used in a thermocouple to measure any temperature range.
a. True
b. False
A
b. False
5
Q
- 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
A
b. used to protect the bulb from erosion, corrosion and impact
5
Q
- Double Bourdon tube gauge is used to measure vacuum only.
a. True
b. False
A
b. False
5
Q
- 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 bellow
A
a. increases the travel of the bellows
6
Q
- Filled thermal elements ____________.
a. always contains 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 with the bi-metal strips
A
b. may be filled with a liquid or gas
6
Q
- 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 temperature reading
e. increase the range of the scale
A
d. increase the accuracy of temperature reading
7
Q
- An absolute pressure gauge uses a/an _____ to sense the pressure.
a. diaphragm
b. bellows
c. bourdon tube
d. spiral Bourdon tube
e. orifice plate
A
b. bellows
7
Q
- Bellows type elements are generally used to measure pressures below 350 kPa.
a. True
b. False
A
a. True
8
Q
- An orifice plate is the most common form of restriction that is used in flow measurement.
a. True
b. False
A
a. True
9
Q
- 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°
b. 180°
c. 120°
d. 90°
e. 270°
A
e. 270°
10
Q
- 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
A
b. False
10
Q
- 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
A
c. is easy to install and replace
11
Q
- 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
A
b. False
11
Q
- 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
A
a. True
11
Q
- 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
A
b. False
12
Q
- 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
A
e. Ethylene glycol and water
12
Q
- The vena contracta 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
A
b. fluid has the smallest cross sectional area
13
Q
- Rotary type positive displacement meters are independent of temperature, pressure and specific gravity.
a. True
b. False
A
a. True
13
Q
- When diaphragms are used as sensing devices to measure level the low-pressure side is filled with a sealing fluid.
a. True
b. False
A
a. True
13
Q
- Float-operated level measurement devices are what?
a. Direct type
b. Indirect type
c. Pressure sensing type
d. Pneumatic type
e. Temperature sensing type
A
a. Direct type
