CS

Finals

True

A 4-20 mA is the most common standard analog signal used in the process control industry nowadays. TRUE OR FALSE

VOLTAGE, TEMPERATURE, WEIGHT

In ISA Symbology, which are the measured variables?

transmitter

The basic function of a \__________ is to convert a reading from a transducer into a standard signal and transmit that signal to a controller or computer monitor.

False

A pump motor is the most commonly used final control element. TRUE OR FALSE

SLOW

If R1 \= 60 Ω, R2 \= 100 Ω, and R3 \= 100 Ω, what is the equivalent resistance (Req) in the circuit?

ANALOG SIGNAL

4-20 MA AND 1 - 5 V

PNEUMATIC SIGNAL

3 -15 PSIG

DIGITAL SIGNAL

FIELDBUS, PROFIBUS AND MODBUS

indicator

A customer would use \__________to read the temperature of a process fluid on a display.

process

Refers to the methods of changing or refining raw materials to create end products.

INCREASE EFFICIENCY, REDUCE VARIABILITY, ENSURE SAFETY

What are the main reasons for manufacturers to control process?

reduce variablity

Process control can reduce variability in the end product, which ensures a consistently high-quality product.

True

Process is defined as the changing or refining of raw materials that pass through or remain in a liquid, gaseous, or slurry state to create end products. TRUE or FALSE

LOAD DISTURBANCE

This is an undesired change in one of the factors that can affect the process variable.

CONTROL LOOP

This is a process management system designed to maintain a process variable at a desired set point.

manual control system

Control operations that involve human action to make an adjustment are called.

Process Control

Refers to the methods that are used to control process variables when manufacturing a product.

Control

Refers to the regulation of all aspects of the process. Precise control of level, temperature, pressure, and flow is important in many process applications.

MEASUREMENT, COMPARISON, ADJUSTMENT

Control loops in the process control industry work in the same way, requiring three tasks to occur:

Setpoint

This is a value for a process variable that is desired to be maintained.

Control Algorithm

A mathematical expression of a control function

manipulated variable

The factor that is changed to keep a measured variable at set point.

50 ft

If the level of a liquid in a tank must be maintained within 5 ft to 50 ft, what is the liquid's setpoint?

Actuating

In basic control system, the input, or the signal (x) also known as?

water level

The height or elevation of water above (more common) or below (less common) a user specified point. This term is used in many applications.

Square with circle inside

Symbol of a field-mounted control/display element.

error

This is the difference between the measured variable and the setpoint and can be either positive or negative.

MAGNITUDE, DURATION, RANGE OF CHANGE

Any error can be seen as having three (3) major components. These three components are:

HELPS ENSURE A CONSISTENTLY HIGH-QUALITY END PRODUCT.

Advantages of reducing variability in a process application.

PHARMACEUTICAL, OIL AND GAS, CEMENT

Examples of the process industry.

offset

This is a sustained deviation of the process variable from the setpoint.

True

A process variable is a condition that can change the process in some way. TRUE or FALSE

False

Automatic control systems are control operations that involve human action to make adjustment. TRUE or FALSE

Hydraulic head

The height to which a column of water is above a reference elevation (e.g., sea level). Like elevation, this term is often used in groundwater applications.

Piping and Instrumentation Diagram

What does the acronym P&ID stand for?

output

The recorder is a device that records the \__________ of a measurement or control devices.

FEEDBACK CONTROL SYSTEM

Close loop control system also known as

True

Imagine you are in a cabin in front of a small fire on a cold winter evening. You feel uncomfortably cold, so you throw another log into the fire. In this scenario, the process variable is temperature. TRUE or FALSE

NON-FEEDBACK CONTROL SYSTEM

Open loop control system also known as?

FINAL CONTROL ELEMENTS

This is a part of the control system that acts to physical changes of the manipulated variable.

THERMISTOR, POTENTIOMETRIC, OPTOELECTRONIC, HALF EFFECT TYPE, LINEAR VARIABLE DIFFERENTIAL TRANSFORMER

Classification of Passive Transducer:

TRANSDUCERS

This is a device that converts one form of energy to other form. It converts the measurand to a usable electrical signal.

True

The thermistor, a thermally sensitive resistor, is made of semi-conducting material. TRUE or FALSE

True

When a pair of electrical conductors are joined together, a thermal emf is generated when the junctions are at different temperatures. TRUE or FALSE

False

The passive transducer are self-generating devices which operate under the energy conversion principle. TRUE or FALSE

ACTIVE TRANSDUCERS

These transducers do not need any external source of power for their operation. Therefore, they are also called as self-generating type transducers.

True

Unlike metals, thermistors respond inversely to temperature. TRUE or FALSE

PASSIVE TRANSDUCERS

These transducers need external source of power for their operation. So, they are not self-generating type transducer.

THERMOCOUPLES

This is a thermoelectric device for measuring temperature, consisting of two wires of different metals connected at two points, a voltage being developed between the two junctions in proportion to the temperature difference.

Piezoelectric, Photovoltaic, Electromagnetic, Chemical, Thermoelectric

Classification of Active Transducer:

True

Most thermocouple signal conditioners usually display the temperature directly and/or provide a voltage that is not proportional to the thermocouple temperature. TRUE or FALSE

ICE POINT COMPENSATION

The leads are connected to a thermocouple signal conditioning box containing an electrical circuit which provides a reference voltage equal to that produced by a reference junction placed at 0°C. This is called.

Thermistor

This is a type of resistor whose resistance is strongly dependent on temperature, more so than in standard resistors.

PNEUMATICS

This is the transmission and control of forces and movements by means of compressed air.

Fluid Power

This is the energy transmitted and controlled by means of a pressurized fluid, either liquid or gas.

False

In preparation of the compressed air, it is okay not to consider the layout of the distribution system. TRUE or FALSE

Seebeck effect

This is a phenomenon in which a temperature difference between two dissimilar electrical conductors or semiconductors produces a voltage difference between the two substances.

BREATH

Pneumatics comes from the Greek work pneuma, which means?

ELECTROMECHANICAL RELAY

This is an electrical switch actuated by an electromagnet coil.

AIR COMPRESSOR

This is used to produce the compressed air for the pneumatic system by the required volume and pressure.

THERMAL, RESISTOR

The term thermistor comes from \__________ and \__________.

False

When a pair of electrical conductors are joined together, a thermal emf is generated when the junctions are at same temperatures. TRUE or FALSE

Resistive Transducers

These transducers are those transducers in which the resistance change due to the change in some physical phenomenon.

strain gauge

This is a device used to measure strain on an object.

Linear Variable Differential Transformers

What does LVDT stand for?

CORROSION AND STICKY OPERATION

In preparation of the compressed air, it should be considered the acceptable humidity to reduce \__________ and \__________.

Ladder Diagram (LD), Structured Text (ST), Instruction List (IL), Function Block Diagram (FBD), Sequential Function Chart (SFC)

The IEC 61131-3 standard specifies five distinct forms of programming language for industrial controllers:

FILTER, REGULATOR, LUBRICATOR

The Air Service Unit is a combination of:

False

The active transducers produce the output signal in the form of variation in resistance, capacitance, inductance, or some other electrical parameter in response to the quantity to be measured. TRUE or FALSE

PROGRAMMABLE LOGIC CONTROLLERS

What does PLC stand for?

RUGGEDNESS

This is ability of transducer to withstand overload and protection measures.

Proximity Switches, Roller-Lever Valves, Air Barrier, Push-Button Valves

In primary levels of pneumatic system, input elements are used such as:

Cavitation

This is the formation of vapor cavities in a liquid.

True

One of the advantages of pneumatics is availability because air is available everywhere in unlimited quantities. TRUE or FALSE

centrifugal

Type of pumps uses rotational kinetic energy to deliver the fluid.

Pascal's Law

The hydraulic system works on the principle of what law?

difficult

As air is compressible, it is \__________ to achieve uniform and constant piston speed.

AND valve

Only when both the inputs are given output is produced.

PRESSURE REGULATION

This is the process of reduction of high source pressure to a lower working pressure suitable for the application.

True

The pump lift should be as small as possible to decrease the cavitation and to increase the efficiency of the pump. TRUE or FALSE