Sensors, Transducers, and Control Devices

Question 1

Is an input device that gives an output of a specified quantity that is useful to the system. These devices are usually part of a bigger system orproject, its output is generally used as an input to the main controller of a
system.

Answer 1

sensor

Question 2

What are the most commonly measured quantities

Answer 2

Acoustic - Wave
Biological & Chemical - Fluid concentration
Electric - Charge, Voltage, Current, Electric Field
Magnetic - Magnetic Field
Optical - Refractive Index, Reflectivity, etc.
Thermal - Temperature, Flux, Specific Heat, etc.
Mechanical - Position, Velocity, Acceleration, etc.

Question 3

What are the 3 different factors considered in choosing which sensor to use for a specific application

Answer 3

• Environmental Factors
• Economic Factors
• Sensor Characteristics

Question 4

Factors such as the temperature range, effect of humidity, corrosiveness, size, protection, susceptibility to electromagnetic interference, ruggedness, power consumption, and self-testing capability must be seen when choosing a proper sensor for a project.

Answer 4

Environmental Factors

Question 5

These focuses on the cost, availability, and lifetime of the device. Other sensors might not be available in the region or might be very costly.

Answer 5

Economic Factors

Question 6

These are the technical characteristics of the sensors such as the sensitivity, range, stability, repeatability, linearity, error, response time, and frequency. For some of the applications that require high precision results, it is important to check on these parameters.

Answer 6

Sensor Characteristics

Question 7

What are the 5 different types of sensors based on the source, form, and others.

Answer 7

• Active vs. Passive
• Digital vs. Analog
• Null and deflection methods
• Input- Output Configuration
• Conversion Phenomenon

Question 8

These are types of sensors that need an external source. This external source is the majority of the output signal.

Answer 8

Active sensors

Question 9

These are type of sensors that works even without external power. The power is drawn from the measured signal itself.

Answer 9

Passive sensors

Question 10

Are sensors that produce digital output (high or low).
Example: Digital Thermometer, Digital thermometers provide a numerical
temperature reading on a digital display.

Answer 10

Digital Sensors

Question 11

Are sensors that give a continuous output. Example:
Pressure Sensor, Pressure sensors measure pressure variations in gases or liquids and convert them into electrical signals proportional to the pressure being sensed.

Answer 11

Analog Sensors

Question 12

What are the 3 Types of Input

Answer 12

Interfering Input
Modifying Input
Desired Input

Question 13

These are the undesired quantities that are unintentionally sensed by the device

Answer 13

Interfering Input

Question 14

Are quantities that cause modification or change at the
output.

Answer 14

Modifying Input

Question 15

Is input quantities that are wanted by the system to be
detected.

Answer 15

Desired Input

Question 16

Sensors use common conversion phenomena such as photoelectric, thermoelectric, electromagnetic, electrochemical, and others

Answer 16

Conversion Phenomenon

Question 17

Are devices that convert the physical
quantity into electrical

Answer 17

Transducers

Question 18

Converts the physical parameters into an electrical signal, while the secondary converts the electrical signal into analog or digital values

Answer 18

Primary Transducer