Controls

Question 1

Types of control agents

Answer 1

internally powered
Pneumatic
Electromechanical
Electronic
Hybrid

Question 2

control systems should be approved by?

Answer 2

CSA/UL/ULC

Question 3

Control agent

Answer 3

The energy that the control system manipulates to cause change in the control medium. (The stuff flowing in the process plant e.g. gas, refrigerant, steam)

Question 4

controlled device

Answer 4

The device that receives the controller’s output signal and regulates the flow of the control agent. Has 2 parts: actuator and final control element.

Question 5

Low limit control

Answer 5

A device that monitors the condition of the controlled medium and interrupts operations if conditions drop below the min value.

Question 6

Peltier effect

Answer 6

The phenomenon where an electric current flowing through the junction of two different metals/conductors causes a temperature difference.

Question 7

Resistance temperature detector (RTD)

Answer 7

A thermometer that operates on electrical resistance; the resistance increases as the temp increases.

Question 8

Thermocouple

Answer 8

A thermometer that generates an electromotive force based on 2 dissimilar metals.

Question 9

By who should control components be approved by

Answer 9

CSA, UL or ULA

Question 10

What is the normal state of a low or high limit controller

Answer 10

Normally Closed