Operator Phase 8 Exam Review

Comprehensive practice flashcards covering all exam questions and concepts from the Operator Phase 8 Exam transcript.

What is the output range ratio of an electronic signal?

$$1 \text{ to } 5$$

What is the primary process value of a control loop?

The measured variable

In a process, what does dead time describe?

The delay between controller input and process action

A bumpless transfer between manual and automatic modes requires some means of matching controller __________.

outputs

Derivative control is especially helpful in doing what to system response?

Minimizing overshoot

Which type of controller output anticipates error?

Derivative

What type of control is used to keep a mixture consistent by controlling one variable in proportion to a second variable?

Ratio control

A $110\,V$ instrument can be expected to operate efficiently within what power supply range?

$$99 \text{ to } 121\,V$$

Feedforward control is especially useful for processes that have what characteristic?

They are slow to respond

How do RTD and thermocouple sensors differ in operating type?

An RTD is a passive sensor, whereas a thermocouple is an active sensor

Unlike supervisory control and direct digital control, what does a distributed control system include?

Digital single-loop controllers

In a cascade control system, the final control element is controlled by which controller?

The slave controller

What shape represents a decision box in a flowchart?

A diamond shape

By definition, what is intrinsically safe equipment?

Equipment that cannot ignite a hazardous atmosphere

In a strain gauge, what property varies in proportion to deformation?

Resistance

Serial-to-parallel and parallel-to-serial conversion for serial data transmission is performed by what integrated circuits?

UARTs

An advantage of lasers over LEDs as light sources in fiber optic systems is that lasers __________.

couple more light energy into the fiber

What function does a multiplexer perform in an optical data transmission system?

It allows signals to share a data link

What is generally the most common and troublesome EMI source?

AC power system

What are the three main components of a PLC?

The programming device, processor unit, and I/O section

What is the first step in constructing a PLC program?

Analyzing the process to be controlled

What is the purpose of a rung comment in PLC programming?

To explain a program operation

If an I/O module supplies current, it is considered what kind of module?

A sourcing module

Which type of data transmission uses a single frequency?

Baseband

What are the two basic categories of air conditioning?

Comfort and process

From the compressor, where does refrigerant flow next in a refrigeration cycle?

To the condenser

An automatic expansion valve is a metering device that maintains a constant pressure in which component?

The evaporator

Air that is saturated is air that is at what temperature?

Dewpoint temperature

To remove moisture that enters a refrigeration system during repair, what device must be used to evacuate the system?

A vacuum pump

What is the "first rule" of preventative maintenance for compressors and related components?

Follow the manufacturer's recommended maintenance schedules and procedures

What is the main function of a control system?

To maintain a variable at a setpoint

What are the basic components of a control system?

Sensor, controller, and controlled device

In an HVAC system, what is rough, irregular airflow called?

Turbulent airflow

Why should an inclined manometer be used rather than a U-tube manometer to measure pressure in branch ducts?

Because the inclined model is more sensitive

After stating the problem, what is the next step in a logical troubleshooting procedure?

Collect data

On a troubleshooting flowchart, what does each box represent?

A checkpoint

Warm, humid days cause heavy evaporator loading, which in turn causes what condition?

High suction pressure