Week 5: Transducers, Industrial Sensors, Signal Conditioning, Sensor Specifications

Question 1

What is a transducer

Answer 1

It is a device that converts a signal from one form of energy to another form

Question 2

What are the components of a transducer

Answer 2

A sensor and a signal conditioning circuit.

Question 3

What is a sensor

Answer 3

A sensor is a device that detects changes in any phsical quantity. It is a device that is used to measure a physical quantity.

Question 4

What is the use of a signal conditioner as it relates to a sensor

Answer 4

To make the output of a sensor readable.

Question 5

What is an industrial detection sensor

Answer 5

An industrial detection sensor is a specialized sensor used in automation to provide real-time data about the processes and equipment being monitored. These sensors enable closed-loop equipment to perform process control and motion control operations.

Question 6

What are some examples of Industrial detection sensors

Answer 6

Temperature sensors, Pressure and flow sensors, Force sensors, Magnetic proximity sensors, Level Sensors

Question 7

What is the function of a signal conditioner

Answer 7

It converts outputs of sensors into their appropriate forms for processing

Question 8

What are the signal conditioning operations or functions

Answer 8

Excitation, Impedance Matching, Linearization, Attenuation, Amplification, Filtering, Digitization

Question 9

What is excitation

Answer 9

Excitation is the external electrical power or stimulus provided to a sensor so it can produce a measurable output signal (voltage, current, frequency, etc.)

Question 10

What are some examples of sensors that require excitation

Answer 10

thermistors, RTD, capacitive level sensors

Question 11

What are some examples of Excitation circuits

Answer 11

Voltage Dividers and Wheatstone bridge

Question 12

What are Voltage dividers

Answer 12

These are used to produce scaled voltages to serve as reference/ sensing values

Question 13

What are Wheatstone Bridges

Answer 13

THis circuit allows for the conversion of resistance changes into a measurable voltage output

Question 14

What is Impedance Matching

Answer 14

This ensures the impedance of the sensor’s output matches or is compatible with that of the load to minimize distortion and protect the sensors.

Question 15

What are examples of Sensors that need Impedance Matching

Answer 15

thermistors, RTD, capacitive sensors, and piezoelectric sensors

Question 16

What are some examples of impedance matching circuits

Answer 16

op-amp buffer, LC circuits, impedance matching transformer

Question 17

How does an Op-Amp provide Impedance Matching

Answer 17

An op-amp is configured as a unity gain buffer where the output is directly connected to the inverting input. The op-amp’s high input impedance prevents it from loading the signal source, and the low output impedance drives.

Question 18

How does the LcC circuits Work

Answer 18

at a specific frequency, the LC components cancel reactive impedance and transform the source impedance to match the load.

Question 19

How does and Impedance Matching transformer work

Answer 19

Impedance-matching transformer with well-selected turns ratio ensures transformed impedance seen by the source equals its output impedance.

Question 20

What is Linearization

Answer 20

Linearisation in signal conditioning refers to the process of converting a nonlinear sensor output into a linear signal, so that the output is directly proportional to the measured physical quantity. output voltage, current, or resistance does not change uniformly with the input.

Question 21

What are some examples of sensors that need linearization

Answer 21

thermistors, thermocouples, capacitive sensors

Question 22

What are some examples of Linearisation Circuits

Answer 22

resistive circuits and op-amp circuits< Log Amplifier.

Question 23

What is a log amplifier used for

Answer 23

Log amplifier is used to provide a voltage proportional to the log of the input when the sensor output is exponential

Question 24

What is filtering

Answer 24

Filtering is used to remove noise due to various external factors, like improper hardware connections and the environment in the output signals.

Question 25

What are the functions of a Filter

Answer 25

Filters ensure that only the useful signal passes through while unwanted components are attenuated or isolated, It also enhances SNR and makes signals more stable for processing.

Question 26

What are some examples of sensors that use filters

Answer 26

Thermocouples ultrasonic,pressure, hall effecr

Question 27

What are the types of filters

Answer 27

Low pass, high pass, band pass, band-reject filters

Question 28

What are some examples of sensors that require amplification

Answer 28

Capacitive, pressure, temperature, strain gauges, load cells, and piezoelectric sensors would need amplification

Question 29

What are circuits used for amplification of sensor signals

Answer 29

inverting, noninverting, and instrumentation amplifiers

Question 30

List some sensor specifications

Answer 30

Operating range, span sensitivity, loading effect error, accuracy, non linearity, resolution, stability, Deaband/time, repeatability, response time, hysterisis

Question 31

Operating range

Answer 31

indicates the limits between which the input can vary.

Question 32

Span

Answer 32

the difference between the maximum and minimum values of the input.

Question 33

Sensitivity

Answer 33

defined as the ratio of the change in output value of a sensor to the per-unit change in input value that causes the output change.

Question 34

Loading effect

Answer 34

The sensor’s input impedance should be high, and the output impedance should be low to avoid the loading effect.

Question 35

Error

Answer 35

the difference between the result of the measurement and the true value of the quantity being measured.

Question 36

Accuracy

Answer 36

the closeness of the agreement between the actual measurement result and the true value of the measurand. It is often expressed as a percentage of the full range output or full–scale deflection.

Question 37

Nonlinearity

Answer 37

indicates the maximum deviation of the actual measured curve of a sensor from the ideal curve.

Question 38

Resolution

Answer 38

the smallest detectable incremental change of input parameter that can be detected in the output signal. Resolution can be expressed either as a proportion of the full-scale reading or in absolute terms.

Question 39

Stability

Answer 39

the ability of a sensor to give the same output when used to measure a constant input over some time.

Question 40

Deadband/time

Answer 40

is the duration from the application of an input until the output begins to respond or change.

Question 41

Repeatability

Answer 41

the ability of a sensor to give same output for repeated applications of same input value. It is usually expressed as a percentage of the full range output

Question 42

Response time

Answer 42

Describes the speed of change in the output on a step-wise change of the measurand. It is always specified with an indication of input step and the output range for which the response time is defined

Question 43

Hysteresis

Answer 43

A sensor error due to the output signal depending not only on the current input but also on the previous state of the input. It causes a lag or difference in readings when the input is increasing versus decreasing.