Sensors measure physical quantities and convert them into signals that are measurable, such as electrical signals. There are many types of sensors classified based on their measuring quantities like acceleration, pressure, viscosity etc. or their operating mechanisms like capacitive, piezoresistive etc. Microsensors are sensors fabricated using microfabrication techniques to miniaturize their size. Example microsensors discussed are capacitive accelerometers, piezoresistive pressure sensors, and conductometric gas sensors. Commercial applications of microsensors include uses in automotive, biomedical, and consumer electronics.
Liquid Sensing: Visible light absorption spectroscopy and colorimetry are two fundamental tools used in chemical analysis. Most of these light-based systems use photodiodes as the light sensor, and require similar high input impedance signal chains. This session examines the different components of a photodiode amplifier signal chain, including a programmable gain transimpedance amplifier, a hardware lock-in amplifier, and a Σ-Δ ADC that can measure a sample and reference channel to greatly reduce any measurement error due to variations in intensity of the light source.
Gas Sensing: Many industrial processes involve toxic compounds, and it is important to know when dangerous concentrations exist. Electrochemical sensors offer several advantages for instruments that detect or measure the concentration of toxic gases. This session will describe a portable toxic gas detector using an electrochemical sensor. The system presented here includes a potentiostat circuit to drive the sensor, as well as a transimpedance amplifier to take the very small output current from the sensor and translate it to a voltage that can take advantage of the full-scale input of an ADC.
Liquid Sensing: Visible light absorption spectroscopy and colorimetry are two fundamental tools used in chemical analysis. Most of these light-based systems use photodiodes as the light sensor, and require similar high input impedance signal chains. This session examines the different components of a photodiode amplifier signal chain, including a programmable gain transimpedance amplifier, a hardware lock-in amplifier, and a Σ-Δ ADC that can measure a sample and reference channel to greatly reduce any measurement error due to variations in intensity of the light source.
Gas Sensing: Many industrial processes involve toxic compounds, and it is important to know when dangerous concentrations exist. Electrochemical sensors offer several advantages for instruments that detect or measure the concentration of toxic gases. This session will describe a portable toxic gas detector using an electrochemical sensor. The system presented here includes a potentiostat circuit to drive the sensor, as well as a transimpedance amplifier to take the very small output current from the sensor and translate it to a voltage that can take advantage of the full-scale input of an ADC.
Basic Principle of Electrochemical SensorTanvir Moin
Electrochemical sensors are the most versatile and highly developed chemical sensors. Electrochemical sensors are a type of chemical sensor that uses an electrode to detect the concentration of an analyte based on a chemical reaction. They are characterized by their low cost, ease of manufacture, rapid analysis, small size, and ability to detect multiple elements simultaneously. They are also powerful analytical tools because of their: Superior sensitivity and selectivity, Quick response period, Simplicity in operation, and Miniaturization.
Routes to Clean Air 2016 - Prof. Alastair C Lewis, The University of YorkIES / IAQM
Talk title: Low- Cost air quality sensors - are they reliable?
Routes to Clean Air is a two-day conference from the IAQM where academics, professionals and policy makers share their experiences of improving traffic emissions.
This event highlights the importance of public communication and behavioural change surrounding road transport and air quality issues.
Basic Principle of Electrochemical SensorTanvir Moin
Electrochemical sensors are the most versatile and highly developed chemical sensors. Electrochemical sensors are a type of chemical sensor that uses an electrode to detect the concentration of an analyte based on a chemical reaction. They are characterized by their low cost, ease of manufacture, rapid analysis, small size, and ability to detect multiple elements simultaneously. They are also powerful analytical tools because of their: Superior sensitivity and selectivity, Quick response period, Simplicity in operation, and Miniaturization.
Routes to Clean Air 2016 - Prof. Alastair C Lewis, The University of YorkIES / IAQM
Talk title: Low- Cost air quality sensors - are they reliable?
Routes to Clean Air is a two-day conference from the IAQM where academics, professionals and policy makers share their experiences of improving traffic emissions.
This event highlights the importance of public communication and behavioural change surrounding road transport and air quality issues.
V A Kamble5.coping of stres5.coping of stres5.coping of stress5.coping of str...VijayKamble86
5.coping of stress5.coping of stress5.coping of stress5.coping of stress5.coping of stress5.coping of stress5.coping of stress5.coping of stress5.coping of stress5.coping of stress
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lecture slides for the topic "Definition and Importance of Entrepreneurship."
Slide 1: Title Slide
Slide title: Definition and Importance of Entrepreneurship
Your name and designation
Date
Slide 2: Introduction
Definition of Entrepreneurship: Entrepreneurship is the process of identifying opportunities, taking risks, and creating new ventures or innovations to deliver value in the marketplace.
Importance of Entrepreneurship: Entrepreneurs play a vital role in economic development, job creation, and driving innovation in various industries, including mechanical engineering.
Slide 3: Characteristics of Entrepreneurs
Creativity and Innovation: Entrepreneurs come up with new ideas and solutions to address existing problems or needs.
Risk-taking: They are willing to take calculated risks to pursue their ventures.
Vision and Passion: Entrepreneurs have a clear vision for their business and are passionate about their ideas.
Persistence: They exhibit determination and perseverance in the face of challenges.
Slide 4: Role of Entrepreneurship in Mechanical Engineering
Application of Innovation: Entrepreneurs in mechanical engineering drive technological advancements through innovative product and process development.
Job Creation: Startups and new ventures create job opportunities for skilled professionals in the engineering field.
Industry Growth: Entrepreneurial ventures contribute to the overall growth and competitiveness of the mechanical engineering industry.
Slide 5: Entrepreneurship vs. Employment
Entrepreneurship: Owning and running a business, taking risks, and enjoying potential rewards of success.
Employment: Working for someone else's business, providing specialized skills, and receiving a fixed salary or wage.
Slide 6: Benefits of Entrepreneurship
Financial Independence: Entrepreneurs have the potential to generate substantial wealth and financial freedom.
Flexibility: They can set their own schedules and make decisions independently.
Impact and Legacy: Successful entrepreneurs leave a lasting impact on society through their innovations and contributions.
Slide 7: Contribution to Society
Social Impact: Entrepreneurs can address societal challenges by developing sustainable and socially responsible solutions.
Technological Advancements: Entrepreneurial ventures drive advancements that improve the quality of life and enhance industry practices.
Slide 8: Examples of Successful Engineering Entrepreneurs
Highlight notable entrepreneurs in the mechanical engineering domain who have achieved significant success and made a positive impact.
Slide 9: Case Study
Present a case study of a successful mechanical engineering startup, discussing their journey, challenges, and achievements.
Slide 10: Summary
Recap the key points covered in the lecture, emphasizing the importance of entrepreneurship in mechanical engineering.
Slide 11: Q&A
Encourage students to ask questions or seek clarification on the topic.
Slide 12: References
List the sources
CW RADAR, FMCW RADAR, FMCW ALTIMETER, AND THEIR PARAMETERSveerababupersonal22
It consists of cw radar and fmcw radar ,range measurement,if amplifier and fmcw altimeterThe CW radar operates using continuous wave transmission, while the FMCW radar employs frequency-modulated continuous wave technology. Range measurement is a crucial aspect of radar systems, providing information about the distance to a target. The IF amplifier plays a key role in signal processing, amplifying intermediate frequency signals for further analysis. The FMCW altimeter utilizes frequency-modulated continuous wave technology to accurately measure altitude above a reference point.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
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Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
HEAP SORT ILLUSTRATED WITH HEAPIFY, BUILD HEAP FOR DYNAMIC ARRAYS.
Heap sort is a comparison-based sorting technique based on Binary Heap data structure. It is similar to the selection sort where we first find the minimum element and place the minimum element at the beginning. Repeat the same process for the remaining elements.
2. What are sensors?
• Sensors measure something, which we call
a measurand.
• There are lots of sensors
– Based on the measurands
– Based on the way they measure
3. Sensors based on the measurand
• Accelerometer
– Measures acceleration
• Gyroscope
– Measures angular rate
• Pressure sensor
– Measures pressure of a fluid
• Viscosity meter
– Measures viscosity of a fluid
• Anemometer
– Measures wind speed
• Bolometer
– Measures radiation
• Blood analyser
– Measures the presence or quantity of a chemical species
• Virus detector
– Detects the presence of a virus
• Etc.
4. Based on the measurement technique
(e.g., accelerometer)
• An apple and a string
• Capacitive
• Piezo‐resistive
• Fluid level
• Tunnelling current
• Laser interferometry
• Open loop or closed loop
a
tan tan
ma a
a g
mg g
g
ma
mg
m
5. Based on the measurement technique
(e.g., accelerometer)
• A mango and a string
• Capacitive
• Piezo‐resistive
• Fluid level
• Tunnelling current
• Laser interferometry
• Open loop or closed loop
6. Based on the measurement technique
(e.g., accelerometer)
• A mango and a string
• Capacitive
• Piezo‐resistive
• Fluid level
• Tunnelling current
• Laser interferometry
• Open loop or closed loop
7. Based on the measurement technique
(e.g., accelerometer)
• An apple and a string
• Capacitive
• Piezo‐resistive
• Fluid level
• Tunnelling current
• Laser interferometry
• Open loop or closed loop
a
8. Based on the measurement technique
(e.g., accelerometer)
• A mango and a string
• Capacitive
• Piezo‐resistive
• Fluid level
• Tunnelling current
• Laser interferometry
• Open loop or closed loop
9. Based on the measurement technique
(e.g., accelerometer)
• An apple and a string
• Capacitive
• Piezo‐resistive
• Fluid level
• Tunnelling current
• Laser interferometry
• Open loop or closed loop
10. Sensors are transducers
• Transducers covert one form of energy to
another form.
Sensor
Measurand Output
Colour change
Shape change
State change
Property change
Change in response
etc.
11. A Sensor’s output is usually electrical.
• Sensors usually covert a measurand to an
electrical quantity.
Sensor
Measurand Output
Voltage
Current
Resistance
Capacitance
Inductance
etc.
12. Quantitative vs. qualitative
• Presence or absence of the measurance
– Is it there or not?
• Qualitative
– High or low or medium…?
• Quantitative
– How much is there precisely?
– We want a number
13. Characteristics of a sensor
• Sensitivity
• Resolution
• Range
• Full scale output (FSO)
• Linearity
• Hysteresis
• Response time
• Drift
• Bandwidth
Magnitude of the
output signal per unit
measurand.
14. Characteristics of a sensor
• Sensitivity
• Resolution
• Range
• Full scale output (FSO)
• Linearity
• Hysteresis
• Response time
• Drift
• Bandwidth
Smallest magnitude of
the measurand that
can be reliably and
repetitively detected.
15. Characteristics of a sensor
• Sensitivity
• Resolution
• Range
• Full scale output (FSO)
• Linearity
• Hysteresis
• Response time
• Drift
• Bandwidth
The difference
between the
maximum and
minimum values of
the measurand that
can be detected.
16. Characteristics of a sensor
• Sensitivity
• Resolution
• Range
• Full scale output (FSO)
• Linearity
• Hysteresis
• Response time
• Drift
• Bandwidth
The difference
between the
maximum and
minimum values of
the output signal.
17. Characteristics of a sensor
• Sensitivity
• Resolution
• Range
• Full scale output (FSO)
• Linearity
• Hysteresis
• Response time
• Drift
• Bandwidth
The extent over which
the output signal is
linear with respect to
the measurand.
18. Characteristics of a sensor
• Sensitivity
• Resolution
• Range
• Full scale output (FSO)
• Linearity
• Hysteresis
• Response time
• Drift
• Bandwidth
The difference
between the output
signals for the same
magnitude of the
measurand while the
measurand is
increasing and
decreasing.
19. Characteristics of a sensor
• Sensitivity
• Resolution
• Range
• Full scale output (FSO)
• Linearity
• Hysteresis
• Response time
• Drift
• Bandwidth
The time lag between
the instance the
measurand changes
and the instance the
output signal changes
completely.
20. Characteristics of a sensor
• Sensitivity
• Resolution
• Range
• Full scale output (FSO)
• Linearity
• Hysteresis
• Response time
• Drift
• Bandwidth
The extent of change
in the output even
when the measurand
is constant.
21. Characteristics of a sensor
• Sensitivity
• Resolution
• Range
• Full scale output (FSO)
• Linearity
• Hysteresis
• Response time
• Drift
• Bandwidth
The range of
frequencies of the
time‐varying
measurand over
which the sensor
responds reliably.
22. The same physical element may be
able to sense multiple things…
Boustraw et al. 1990;
flow‐rate sensor
Can also
measure…
Temperature,
Vibration
Sound
Radiation
Chemical species
etc.
24. Micromachined accelerometers:
two examples
M. Lemkin, M. Ortiz, N. Wongkomet, B. Boser, and J. Smith, ʺA
3‐axis surface micromachined sigma‐delta accelerometer,ʺ Proc.
ISSCC ʹ97, pp. 202‐203, 1997.
ADXL202E by Analog Devices Sandia National Laboratories
25. Measurement of displacement
• There are several other ways of
detection.
– Capacitve
– Piezoelectric
– Piezoresistive
– Magnetic
– Optical
• Single‐axis or multiple axes?
• Cross‐axis sensitivity?
• Over‐range protection?
• Direct mode
• Force‐feedback mode
( )
x t
m
k
b
26. A tradeoff in (micromachined)
accelerometers
mx bx kx ma
x m
kx ma
a k
resonance
k
f
m
Sensitivity
Resonance frequency
High sensitivity implies low resonance frequency;
Low resonance frequency implies small operational range.
At steady state…
But, …
( )
x t
m
k
b
Seismi
c mass
Over‐range
protection
Tradeoff is
necessary
27. The effect of damping
m
k
f
2
b km
2
b km
2
b km
Critical damping
under damping/resonating
over damping
Over‐damping reduces the useful frequency range.
Under‐damping causes peaking that may lead to mechanical failure.
Thus, damping is usually necessary but not too much or too little.
28. Getting linearity…
0 0 0 0
2 2
0 0
2 2
out
A A A A
xd x
d x d x d x d x
V V V V V for x d
A A d x d
d d
Good
linearity
29. Capacitance extraction circuit
Chopper stabilization with
boosted gain and correlated
double sampling with cross‐
coupled switches.
This helps reduce 1/f noise and
offset.
1 part per million resolution
2.3 mV noise
30. System level simulation
a+an
x
A demodulator
Low‐pass
filter
Vout
PID
Mechanical
Brownian noise
+
Acceleration
signal
Electronic noise
and offsets
Mass and
suspension
C1
C2
ε0A/(d+x)
ε0A/(d‐x)
+Vm
‐Vm
feedback
4
m
s
V a m
V
k d
Vn
31. A real accelerometer made in IISc
The waveforms show the responses of
the standard STM accelerometer and
IISc’s accelerometer under test when a
0.5 g is applied .
Yellow : Standard accelerometer
Pink : SOIMUMPs accelerometer
Sambuddha Khan
Thejas
Annathasuresh
Bhat
(2009‐2010)
32. Accelerometer: a summary
Summary
Category Sensor
Purpose Measures the acceleration of the body on which this sensor is mounted.
Key words Proof-mass
Suspension
Principle of operation Converts the displacement caused by the inertial force on the proof-mass to a
voltage signal via change in capacitance between movable and fixed parts.
Application(s) Automotive, aerospace, machine tools, bio-medical, etc.
34. Piezoresitive pressure sensor
Summary
Category Sensor
Purpose Measures the pressure, typically of gases or liquids.
Key words Piezoresistivity, diaphragm
Principle of operation The external pressure loading causes the deflection, strain, and stress on the
membrane. The strain causes change in the resistance of a material, which is
measured using Wheatstone bridge configuration.
Application(s) Automotive industry, aerospace applications, appliance industry, bio-medical
etc.
36. Conductometric gas sensor
Summary
Category Sensor
Purpose It detects and quantifies the sources of a gas, i.e., its concentration
Key words Catalyst, combustible, adsorption, desorption
Principle of operation The principle is that a suitable catalyst, when heated to an appropriate
temperature, either promotes or reduces the oxidation of the combustible
gases. The additional heat released by the oxidation reaction can be detected.
The fundamental sensing mechanism of a gas sensor relies on a change in the
electrical conductivity due to the interaction process between the surface
complexes such as O-,O2-,H+, and OH- reactive chemical species and the gas
molecules to be detected.
Application(s) Environmental monitoring, automotive application and air conditioning in air
planes, spacecrafts and houses and sensor networks, ethanol for breath
analyzers and food control application etc.
37. Conductometric gas sensors
Nanomaterials Research Inc. gas sensors
Typical materials used: Films of metal oxide like SnO2 and Tio2
Sample fabrication process: Gas sensors are fabricated using the single crystalline SNO2
nanobelts. Nanobelts are synthesized by thermal evaporation of oxide powders under controlled
condition without the presence of a catalyst.
38. A conductometric gas sensor:
how doe it work?
Conductivity: It is a property of material that quantifies the material’s ability to conduct
electric current when an electric potential (difference) is applied. It depends on the number
of free electrons available.
Adsorption: Adsoprtion is the process of collection and adherence of ions, atoms, or
molecules on a surface. This is different from absorption, a much more familiar term. In
absorption, the species enter into the bulk, i.e., the volume. On the other hand, in
adsorption, they stay put on the surface.
Desorption: This is the reverse of adsorption; species (ions, atoms, or molecules) or given
out by the surface.
Combustion: It is a technical term for burning. It is a heat-generating chemical reaction
between a fuel (combustible substance) and an oxidizing agent. It can also result in light
(e.g., a flame).
Pre adsorption of oxygen on semiconducting material surface.
Adsorption of a specific gas that is to be detected.
Reaction between oxygen and the adsorbed gas.
Change in the conductivity of the resistor element.
Desorption of reacted gas on the surface for re‐use.
39. Hand‐held blood analyzer
Abbott Point of Care
http://www.istat.com/
The chip is
small but the
system is
big.
With a few drops of
blood, under a minute it
gives blood analysis:
gases, chemistry, cardiac
markers, etc.
40. Main points
• Sensors are transducers.
• Usually the output is electrical.
• Characteristics of sensors
• Miniaturization helps…
– Because the cost, size, and power consumed are
reduced while improving the performance.
• A lot of commercial microsensors are now
available.
• The scope for further research and
development is unlimited.