Post on 14-Apr-2018
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 1/40
EI MODULE 4
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 2/40
DATA ACQUISITION SYSTEM (DAS)
• Data acquisition generally relates to the
process of collecting the i/p data in digital
form as rapidly, accurately, and economically
as necessary.
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 3/40
GENERALIZED DATA ACQUISITION
SYSTEM
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 4/40
VARIOUS GENERAL CONFIGURATION
1. Single channel possibilities
• Direct conversion
• Pre-amplification and direct conversion
•Sample and hold, and conversion
• Pre-amplification, signal conditioning and any of the above
2. Multi channel possibilities
• Multiplexing the o/p of single channel converters• Multiplexing the o/p of sample-hold circuits
• Multiplexing the i/p of sample-hold circuits
•
Multiplexing low level data
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 5/40
DIGITAL DAS
Transdu
cer
Signal
conditioni
ngequipment
Multipl
exer
Signal
convert
er
A/D
convert
er
Digital
recoder
Auxiliary equipment and systemprogrammer
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 6/40
SINGLE CHANNEL DAS
A/D Converter BufferTo
Computer
Print Out/
Storage
Convert
Command
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 7/40
OBJECTIVE OF DAS
DAS in ‘Electronic Instrumentation’ by H S Kalsi
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 8/40
SIGNAL ANALYZERS
• Wave analyzers – frequency selective
voltmeter, carrier frequency voltmeter, and
selective level voltmeter.
• Distortion analyzer – Harmonic distortion
analyzers.
• Spectrum analyzers.
• All case analysis in frequency domain.
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 9/40
WAVE ANALYZER
• To measure the amplitude of each harmonic
or fundamental individually.
• It has a very narrow pass – band.
• Range – low RF range below 50Mhz and down
through AF range.
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 10/40
BASIC WAVE ANALYZER
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 11/40
FREQUENCY SELECTIVE WAVE
ANALYZER
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 12/40
RELATIVE RESPONSE IN DBS
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 13/40
HETERODYNE WAVE ANALYZER
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 14/40
RF HETERODYNE WAVE ANALYZER
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 15/40
Harmonic distortion analyzer
• Total harmonic content
• Simplest method – high pass filter whose cut
off freq is a little above fundamental freq.
• Other types
Employing A Resonance Bridge
Wien's Bridge MethodBridged T-Network Method
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 16/40
RESONANCE BRIDGE METHOD
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 17/40
WIEN'S BRIDGE METHOD
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 18/40
BRIDGED T-NETWORK METHOD
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 19/40
HARMONIC DISTORTION ANALYZER
USING BRIDGED T-NETWORK
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 20/40
SPECTRUM ANALYZER
• Frequency domain view.
• Graphical display on its CRT, with freq on
horizontal axis and amplitude (voltage) on
vertical axis.
• Spectrum analyzer use either Parallel Filter
Bank or a Swept Frequency Technique
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 21/40
SPECTRUM ANALYZER
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 22/40
SPECTRUM ANALYZER USING SWEPT
RECEIVER DESIGN
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 23/40
TEST WAVE AND DISPLAY OF
SPECTRUM
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 24/40
TEST WAVEFORM ON X AXIS(TIME) & Z
AXIS(FREQ)
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 25/40
RF SPECTRUM ANALYZER
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 26/40
Signal Analyzers in ‘Electronic Instrumentation’ by HS Kalsi
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 27/40
PROGRAMMABLE LOGIC CONTROLLER
(PLC)
• The processor in a PLC system has software that
is easily programmable and flexible, making the
initial program, updates, modifications, and
changes easy to implement.• PLCs are categorized into low-end, midrange, and
high-end, where low-end is from 64 expandable
up to 256 I/Os, midrange is expandable up to2,048 I/Os, and high-end is expandable up to
8,192 I/Os.
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 28/40
BLOCK DIAGRAM OF A CONTROL LOOP
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 29/40
BLOCK DIAGRAM OF PROGRAMMABLE
CONTROLLER
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 30/40
COMPUTER-BASED DIGITALLY
CONTROLLED PROCESS
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 31/40
BLOCK DIAGRAM OF PROCESSING
UNIT
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 32/40
PH MEASUREMENT
• pH is a parameter that quantifies the level of
acidity or alkalinity in a chemical solution
• pH ranges from 0 to 14
• An excess of hydrogen ions causes acidic, and
an excess of hydroxyl ions causes alkaline
• Neutral solution like pure water has a pH
value of 7
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 33/40
PH MEASUREMENT
• The pH value is given by
pH = log10 [1/hydrogen ion concentration]
• Scale range from 0 to 14
• Acidic solution pH value b/w 0 to 7
• Alkaline solution pH value b/w 7 to 14
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 34/40
PH APPLICATION CONSIDERATIONS
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 35/40
THERMAL-CONDUCTIVITY(GAS
ANALYZER)
• Chemical purity of gas
• Based on vast difference in heat conductivity
among gases
• Measured by bridge circuit using sensing
resistors and thermistors
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 36/40
DSO (Digital Storage Oscilloscope)
• DSO – processing and non processing
• Processing type – built in computing power(data
in digital form), processing capability ranges from
simple (avg, area, rms etc.) to complete FFTspectrum analysis capability
• Non processing type – designed as replacement
for analog instrument or both storage and nonstorage types. Their many desirable features seen
set to replace analog scopes entirely (within BW
range where digitization is feasible)
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 37/40
COMPONENTS OF DSO
Amplifier/Atte
nuatorA/D Converter
Acquisition
Memory
Display
Display
Memory Microprocessor
I/p
Voltage
S/g
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 38/40
DSO
• Scope of DSO
• Commercial DSO – features
• Precaution
• ‘Electronic Instrumentation’ by H S Kalsi
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 39/40
Strain measurement
• Ballast circuit
• Deflection type Wheatstone bridge
• Temp compensation technique
• Uses of strain gauge
• “Electrical and Electronic Measurement &
Instrument” by A K Sawhnay
7/27/2019 EI Module 4.pdf
http://slidepdf.com/reader/full/ei-module-4pdf 40/40
• Pressure, flow, temp, force, torque, mass
measurements any three method.
• Syllabus Reference – 1, 4 & 7
• Doeblin, Morris and Rangan