Temperature sensing devices

Question 1

The amount a metal will expand when exposed to heat is determined by

Answer 1

the type of metal used
the amount of heat applied
the density of metal

Question 2

when used in an industrial sensing application, a heated metal will

Answer 2

Expand

Question 3

With the heating of a metal bar

Answer 3

a small movement of the bar causes a great movement of an attatched mechanical arm

Question 4

if the electrical contacts are permitted to open an close slowely

Answer 4

poor contact pressue will result
cntact burnout can occur

Question 5

Hot wire starting relays are often used in the

Answer 5

Refrigeration industry

Question 6

a metal that remains in liquid state at room temperature is

Answer 6

mercury

Question 7

two dissimilar metals bonded together have

Answer 7

different expansion rates

Question 8

an RTD is made out of

Answer 8

Platinum Wire

Question 9

a bellows type thermostat works on a change in

Answer 9

pressure principle

Question 10

the most common heat sensing device used in room thermostats and thermometers is the

Answer 10

bimetal strip

Question 11

a long bimetal strip

Answer 11

exhibits a greater movement with greater heat

Question 12

when the resistive wire heats up due to excessive motor current

Answer 12

the run winding contacts open

Question 13

with spiral shaped bimetal strip, if collabarated scale is placed behind a pointer when attached to centercenter of the spiral, it becomes a

Answer 13

thermometer

Question 14

with spiral shaped bimetal strip, if collabarated scale is placed behind a pointer when attached torge center of the spiral, it becomes a

Answer 14

thermometer

Question 15

the heating of two dissimilar metals to produce a voltage at the junction is known as the

Answer 15

seebeck effect

Question 16

a device that employs the heating of two dissimilar metals to produce voltage is known as a

Answer 16

thermocouple

Question 17

a thermopile exists when

Answer 17

two or more thermocouples are connected in series

Question 18

with an rtd probe

Answer 18

copper is used to provide good thermal contact

Question 19

a device that works on the principle of a change in resistance with a change in heat is known as

Answer 19

reluctance temperature detector

Question 20

thermosistors exhibits

Answer 20

a rapid change of resistance with a change in temperature

Question 21

this type of relay is named because it uses a length of resistive wire connected in series with the motor to sense motor current

Answer 21

Hot wire relay

Question 22

since thermocouples produce such low voltages they are often connected in series, this connection is known reffered to as

Answer 22

thermopile

Question 23

a very common and reliable method of sensing temperature is by the expansion of metal

Answer 23

true

Question 24

Ttwhen two dissimillar metals are joined at one end , and the that junction is heated , a voltage is produced

Answer 24

true