analog and digital ppt Flashcards
refers to a category of devices and systems
used for measuring, displaying, and recording analog signals to obtain real-time
data and information about various physical phenomena.
Analog electronic instrumentation
it is a voltage or current whose magnitude represents some physical measurement or control quantity.
Analog electronic instrumentation
play a fundamental role in instrumentation and control systems, serving as the cornerstone for the measurement, monitoring, and regulation of a wide range of physical parameters.
Analog electronic instrumentation
These analog signals offer a
continuous representation of the quantity being measured, making them
indispensable for ensuring accurate control and monitoring of industrial processes.
Analog electronic instrumentation
some common applications of analog electronic signals in instrumentation and Control:
-PID CONTROLLER
-TEMPERATURE MEASUREMENT
-PRESSURE MEASUREMENT
-LEVEL SENSING
-FLOW RATE MEASUREMENT
if the process pressure is ..
75%
what’s its bar and analog input?
7.5 bar and 16mA
if the process pressure is ..
0%
what’s its bar and analog input?
0 bar and 4mA
if the process pressure is ..
25%
what’s its bar and analog input?
2.5 bar and 8mA
if the process pressure is ..
50%
what’s its bar and analog input?
5 bar and 12mA
if the process pressure is ..
100%
what’s its bar and analog input?
10 bar and 20mA
This is an analog signal standard, meaning
that the electric current is used to proportionately represent measurements or command signals.
4 TO 20 mA ANALOG CURRENT SIGNALS
The most popular form of signal transmission used in modern industrial
instrumentation systems.
4 TO 20 mA ANALOG CURRENT SIGNALS
An important concept to grasp with all analog instrumentation is that instruments sending and receiving analog signals
must be compatibly ranged in order to properly represent the desired variable.
are also used in control systems to command the positioning
of a final control element, such as a control valve or a variable-speed motor
drive (VSD).
DC current signals
In these cases, (analog electronic signals) the milliamp value does not directly represent a process measurement, but rather how the degree to which the final control element influences the process.
true
state the cycle of process of analog electronic signal
the process=> measuring device (senses) =>
[4-20 mA PV signal] => controller (decides) => [4-20 MV signal] => final control device (influences) => the process (reacts)
Why 4-20mA and not 0-20mA?
In this case, it would be extremely difficult to identify that either 0mA current is due to open circuit of the transmitter or it is due to no pressure of the fluid. Hence, if the transmitter is calibrated to generate current signal in the range of 4-20mA, the faults like open circuits can easily be detected
Why 4 mA?
instead of zero, to know if there’s a fault and for it to be not a value.
Why 20 mA?
it is not easily disturbed. And the internal resistance of the current source is infinite, and the resistance of the wire in series in the loop does not affect the accuracy, and it can transmit hundreds of meters on the ordinary twisted pair.
Why do we need to convert 4-20mA into voltage?
A current loop requires voltage to drive the current
A 4 to 20 mA current signal represents some signal along a 0 to 100 percent
scale. Usually, this scale is linear,
true
For example, if we were to calibrate a 4-20 mA temperature transmitter for a measurement range of 50 to 250 degrees
C,
we could relate the current and measured temperature values on a graph like ..
linear graph from 50-250
is the type used to represent the
output of a process controller, sending a command signal to a final control
element.
simplest form of 4-20 mA current loop
CONTROLLER OUTPUT CURRENT LOOPS examples
-4-wire (“self-powered”) transmitter current loops
-2-wire (“loop-powered”) transmitter current loops
-Troubleshooting Current Loops
Before the widespread adoption of reliable electronic instrumentation, industrial
processes heavily relied on instruments that operated using compressed air.
These instruments transmitted process measurement signals as air pressures
through long runs of metal tubing.
pneumatic instrumentation
these air-powered
devices were mechanically complex and required frequent adjustments to
maintain high accuracy.
instrument mechanics
Many pneumatic instruments use a sensitive mechanism called a _____
which involves a flat object blocking the airflow from a small nozzle.
baffle-and-nozzle
assembly
is often used directly in quality control work, checking for proper dimensioning of machined metal parts.
operation of a baffle/nozzle mechanism
are used to automatically achieve and maintain a state of balance or equilibrium by adjusting their internal components, often with
compressed air.
Self-balancing pneumatic instruments
They are commonly employed in measurement and control systems to ensure accurate and stable operation by compensating for
variations in the monitored or controlled process.
Self-balancing pneumatic instruments
which boosts sensitivity, similar to an electronic
amplifier, improving precision by amplifying small air pressure changes.
a pneumatic amplifier,
This _____
functions like an electronic transistor, enhancing accuracy and responsiveness in self-balancing systems.
pneumatic amplifier
The gain (A) of any pneumatic relay is defined just the same as the gain of
any electronic amplifier circuit, the ratio of output change to input change:
A= ΔOutput / ΔInput
EXAMPLES WHERE DIGITAL DATA ACQUISITION ARE USED
-Smart manufacturing
-Smart grids
-Connected vehicles
The most crucial rule for using pneumatic instruments is to maintain clean and
dry instrument air. Contaminated compressed air, with dirt, rust, oil, or water, can lead to operational issues in pneumatic instruments.
true
In a smart factory, DAQ sensors are used to collect data on
all aspects of the manufacturing process, from the quality of raw materials to the
performance of machines. This data is transmitted over networks to central computers, where it is analyzed to identify potential problems and optimize production.
Smart manufacturing
in Pilot Valves and Pneumatic Amplifying Relays,
To ensure accuracy in self-balancing systems, sensitivity in the imbalance detection mechanism is
vital. While reducing the orifice size makes it more sensitive, it can slow the system and make it prone to clogging.
true
these can reduce output
pressure
Clogged orifices
these can increase output pressure.
clogged nozzles
To address clogs, _____ can be used to break loose debris.
a welding torch tip cleaner
these have drawbacks compared to electronic ones. They’re
more sensitive to factors like vibration and temperature changes, affecting
calibration accuracy. Using compressed air is costlier than electricity, raising operational
costs.
Pneumatic instruments
Installation involves ______ which can slow instrument response.
special tubing
Another advantage of pneumatic instruments…In remote natural gas installations, the instruments can use
the natural gas itself as a power source, eliminating the need for an air
compressor or electrical power.
can operate using compressed
gases other than air.
is the process of collecting and
processing data from various sources, such as sensors and
transducers, and converting it into digital format for storage and
analysis.
Digital data acquisition
these are self-purging, releasing compressed air to keep the
inside clean, even if the exterior is dirty. In larger enclosures, they provide a
positive-pressure air purge to protect all devices.
Pneumatic instruments
One significant advantage is ______ They don’t use electricity, so
they can’t generate sparks. This makes them ideal for environments with
explosive gases, liquids, dust, or powders.
intrinsic safety.
This process involves several stages, including signal
conditioning, analog to digital conversion, and digital signal
processing.
Digital data acquisition
can function in high-temperature and
high-radiation environments, which could harm electronic instruments. They are
naturally immune to such conditions.
pneumatic instruments
use digital data acquisition sensors to monitor power generation, transmission, and distribution. This data is used to control the flow of electricity and respond to disruptions.
Smart grids
Digital data acquisition sensors can be used to monitor
air quality, water quality, and other environmental conditions. This data can be
transmitted over networks to central computers for analysis and reporting.
Environmental monitoring
advantage of pneumatic instruments….
However, ________ is essential to
prevent contaminants in the natural gas from affecting the sensitive instrument
mechanisms.
good filtering equipment
use digital data acquisition sensors
to collect data on their own performance and the surrounding environment.
This data is transmitted to other vehicles and infrastructure over networks to
improve safety and efficiency.
Connected vehicles
APPLICATIONS OF DIGITAL DATA ACQUISITION AND
INSTRUMENTATION AND CONTROL
-Environmental monitoring
-Medical devices
-Scientific research
Many medical devices, such as pacemakers and insulin pumps,
use digital data acquisition sensors to collect data on the patient’s condition. This data
is used to control the device and ensure that it is functioning properly.
Medical devices
Digital data acquisition systems are widely used in scientific research to collect data from experiments and simulations. This data is transmitted over networks to researchers around the world for analysis and collaboration.
Scientific research
ENHANCING PRECISION examples
-Digital data acquisition systems
-Networks
-Instrumentation and Control systems
can be designed to very high precision
standards, with accuracies of up to 0.01%
-in enhancing precision
Digital data acquisition systems
can provide reliable and timely transmission of DAQ data, even
over long distances.
-in enhancing precision
networks
can use Digital data acquisition data
to control physical processes with high precision.
-in enhancing precision
Instrumentation and Control systems
ENHANCING EFFICIENCY
-Digital data acquisition systems
-Networks
-Instrumentation and Control systems
in ENHANCING EFFICIENCY
can automate the collection and
processing of data, eliminating the need for manual intervention.
Digital data acquisition systems
in ENHANCING EFFICIENCY
can enable digital data acquisition data’s to be accessed and
shared by multiple users and devices, improving efficiency and collaboration.
Networks
in ENHANCING EFFICIENCY
can use digital data acquisition
data’s to optimize physical processes, reducing waste and improving
productivity.
Instrumentation and Control systems
Instrumentation is used in a wide range of industrial
processes, including:
- Manufacturing
- Energy production
- Oil and gas
- Water and wastewater treatment
WHAT ARE THE THREE MAIN COMPONENTS
OF INSTRUMENTATION AND CONTROL?
Sensor
Controller
Final Control Element
WHAT ARE THE ROLES OF
INSTRUMENTATION IN MEASURING AND
CONTROLLING INDUSTRIAL PROCESS?
- Provide real-time data on key process variables
- Enable process control systems to monitor and adjust the process
- Improve product quality and consistency
- Reduce waste and improve efficiency
- Improve safety
WHY DO WE NEED PRECISE DATA
ACQUSITION IN THE FIELD OF
INSTRUMENTATION
- Ensure the accuracy of process control systems
- Enable the detection of small changes in process variables
- To meet regulatory requirements
- To facilitate continuous improvement
A SPECIFIC FIELD THAT
SHOWS THE IMPORTANCE OF PRECISE
DATA ACQUISITION IN INSTRUMENTATION
-PHARMACEUTICAL PLANT
-POWER PLANT
-OIL REFINERY
WHAT ARE THE CHALLENGES IN
ACHIEVING PRECISE DATA ACQUISITION?
-SENSOR NOISE
-SIGNAL TRANSMISSION
-CALIBRATION
WHAT ARE THE TECHNIQUES IN ACHIEVING
PRECISE DATA ACQUISITION?
-USING HIGH-QUALITY SENSORS AND INSTRUMENTATION
COMPONENTS.
-CAREFULLY DESIGNING AND INSTALLING THE INSTRUMENTATION
SYSTEM
-USING NOISE REDUCTION TECHNIQUES
-USING REDUNDANT SENSORS AND OTHER INSTRUMENTATION
COMPONENTS
-REGULARLY CALIBRATING THE INSTRUMENTATION SYSTEM
WHAT ARE THE STEP BY STEP
PROCESS OF INTEGRATION?
- Sensors and Transducers
- Analog-to-Digital Conversion (ADC)
- Data Acquisition System
- Signal Conditioning
- Data Storage
- Data Analysis and Visualization
- Communication and Integration
- Feedback and Control
GIVE EXAMPLES OF DIGITAL
SENSORS AND TRANSDUCERS
USED IN INSTRUMENTATION
-Digital Pressure Sensors
-Digital Thermometers
-Digital Temperature Sensors:
-Digital Encoders
-Digital Imaging Sensors
-Limit Switches
-Hall Effect Sensors
WHY DOES DIGITAL SENSORS AND
TRANSDUCERS ARE BECOMING
INCREASINGLY POPULAR
They offer superior accuracy and versatility due to less signal noise, and their digital format makes them easier to use with computers for analysis and control systems.
DIGITAL SIGNAL PROCESSING IN
CONTROL SYSTEMS
-FILTERING
-AMPLIFICATION
-INTEGRATION AND DIFFERENTIATION
-FAST FOURIER TRANSFORM
EXAMPLES OF DIGITAL SIGNAL
PROCESSING IN CONTROL
APPLICATIONS
-MOTOR CONTROL
-ROBOTICS
-PROCESS CONTROL
-AIRCRAFT CONTROL
-AUTOMOTIVE CONTROL
-MEDICAL DEVICES
-DATA ANALYSIS
NETWORKS IN INDUSTRIAL
AUTOMATION
-Field Networks
-Control Networks
-Information Networks
WHAT ARE THE WAYS THAT NETWORKS ENABLE
SEAMLESS COMMUNICATION BETWEEN
INSTRUMENTS AND CONTROL SYSTEMS?
-Data transmission
-Data sharing
-Remote monitoring and control
-System integration
TYPES OF NETWORKS USED FOR CONNECTING
INSTRUMENTS AND CONTROL SYSTEMS
-Fieldbus
-Industrial Ethernet
-Wireless networks
ADVANTAGES OF REAL-TIME DATA TRANSMISSION
IN INDUSTRIAL SETTINGS.
-Improved efficiency
-Enhanced safety
-Better decision-making
-Increased competitiveness
SCADA systems typically consist of three main components:
-Sensors and actuators
-Field controllers
-SCADA master station
also allows the operators to send commands to the
field controllers.
SCADA master station
it is a central computer that collects data from the field controllers and displays it to the operators.
SCADA master station
are located near the process and are
responsible for collecting data from the sensors and sending it to the SCADA
master station.
Field controllers
collect data on the process variables, such
as temperature, pressure, flow rate, and level.
Sensors
also receive commands from the SCADA master
station and send them to the actuators.
Field controllers
are used to control the
process variables, such as opening and closing valves and adjusting the speed of motors.
actuators
BENEFITS OF SCADA IN NETWORK
CONTROL
-Real-time monitoring and control
-Alarm management
-Data logging and trending
-Remote monitoring and control
CHALLENGES IN INSTRUMENTATION &
CONTROL NETWORKS
-Harsh environmental conditions
-Legacy systems
-Multiple vendors
-Limited IT resources
-Sophisticated cyberattacks
HOW WILL YOU ADRESS THESE CHALLENGES?
-Invest in ruggedized networking equipment
-Modernize legacy systems
-Use a single vendor
-Partner with a managed security services provider
-Implement a layered security approach
-Develop and implement a network security policy
-Regularly train employees on cybersecurity
-Keep software up to date
-Monitor the network for suspicious activity
NETWORK FAILURES ON CONTROL SYSTEMS
-Disruption of operations
-Inaccurate data
-Security vulnerabilities
WHAT STEPS COULD BE TAKEN TO MITIGATE THE RISK OF NETWORK
FAILURE ON CONTROL SYSTEMS?
-Implement robust network security measures, such as firewalls,
intrusion detection systems, and access control lists.
-Use redundant network connections, so that if one network fails, the
control system can still communicate with the devices it controls.
-Have a plan in place to respond to network outages. This plan should
include steps to identify and diagnose the problem, and to take
corrective action to minimize the impact of the outage.
FUTURE TRENDS IN
INSTRUMENTATION & CONTROL
-More complex and efficient control algorithms
-Adaptive control
-Predictive control
-Decision-making
ADVANCED SENSOR TECHNOLOGIES
-Improved accuracy and sensitivity
-Increased miniaturization and portability
-New sensing modalities
EXAMPLES OF EMERGING SENSOR
TECHNOLOGIES THAT ENHANCES
DATA ACQUISITION
-Graphene sensors
-Quantum dot sensors
-Microfluidic sensors
-Fiber optic sensors
-Hyperspectral sensors
