Line C Control Point Instrumentation

Question 1

For control point instrumentation, what does RTD stand for?

Answer 1

Resistance temperature detector

Question 2

What type of RTD is mostly used in the industrial sector?

Answer 2

Coiled element RTD

Question 3

The known electrical resistance at a specific temperature of the metal that makes up an RTD allows the RTD to be accurate within its temperature limits.

Answer 3

True

Question 4

What metal is most commonly used in an RTD in industrial applications?

Answer 4

Platinum

Question 5

How does an RTD work?

Answer 5

The resistance increases as the temperature of the sensor increases

Question 6

Which is the most common RTD wiring configuration that gives a good combination of accuracy and convenience?

Answer 6

3-wire

Question 7

A 4-wire RTD gives the best accuracy even though most industrial controllers/measurement devices cannot make a true four wire measurement.

Answer 7

True

Question 8

What is the characteristic of a 3-wire RTD configuration?

Answer 8

It allows the measurement to factor out the resistance of the leads

Question 9

What type of circuit is used in an RTD to measure the resistance?

Answer 9

Wheatstone bridge

Question 10

How does a thermocouple interpret changes in temperature?

Answer 10

Change in Voltage

Question 11

A ____________ has wider operation ranges than an RTD.

Answer 11

Thermocouples

Question 12

RTDs are more sensitive than thermocouples thus they react faster.

Answer 12

False

Question 13

Which statement is true when comparing thermocouples to RTDs?

Answer 13

Thermocouples react faster than RTDs, but RTDs are more accurate

Question 14

What can limit the maximum range of a thermocouple?

Answer 14

Its diameter

Question 15

How does a pressure transducer work?

Answer 15

It converts pressure into an electrical signal

Question 16

What produces the electrical signal in a pressure transducer?

Answer 16

Strain gauge

Question 17

What types of electrical output is available for a pressure transducer?

Answer 17

Millivolt, 0-10 Voltage, 4-20 mA

Question 18

How many platinum RTDs does a thermal mass flow meter use?

Answer 18

2

Question 19

In a thermal mass flow meter, what task does each RTD perform?

Answer 19

One RTD measures the fluid temperature and the second maintains a constant temperature differential above the process fluid

Question 20

What three things is an automatic O2 trim system designed to compensate for?

Answer 20

Fuel characteristics, temperature, barometric pressure

Question 21

What sensor is the critical component used to reduce emissions in a modern biomass boiler?

Answer 21

O2 sensor

Question 22

To give better control and more consistent/accurate positioning for a modulating burner, in what system are servo motors used?

Answer 22

In a parallel positioning system