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Limited
Certification for Ultrasonic A-Scan Thickness
Measurement
Course Outlines as
per SNT-TC-1A
1.0
Principles /
Theory
1.1 General
1.2 Principals
of acoustics
1.2.1
Nature of
sound waves
1.2.2
Modes of
sound wave generation
1.2.3
Velocity,
frequency and wavelength of sound waves.
1.2.4
Attenuation
of sound waves
1.2.5
Acoustic
Impedance
1.2.6
Reflection
2.0 Equipment
/ Materials
2.1 Equipments
2.1.1 Pulse
echo instrumentation
2.1.1.1
Control and
Circuits
2.1.1.2
Pulse
generation
2.1.1.3
Signal
Detections
2.1.1.4
Display and
recording methods , A-scan, B-scan, C-scan and digital
2.1.1.5
Sensitivity
and resolution
2.1.1.6
Gates ,
Alarms and Calibration
2.1.1.7
Basic
Instrument calibration
2.1.1.8
Calibration
blocks
2.1.2 Digital
Thickness instrumentation
2.1.3 Transducer
operation and theory
2.1.3.1
Piezoelectric effect
2.1.3.2
Types of
crystals
2.1.3.3
Frequency
(crystal –thickness relationships)
2.1.3.4
Types
(straight, angle, single dual etc.)
2.2
Materials
2.2.1 Couplants
2.2.1.1
Purpose and
principles
2.2.1.2
Material
and their efficiency
2.2.2 Calibration
Blocks
2.2.3 Cables/connectors
2.2.4 Test
Specimen
2.2.5 Miscellaneous
materials
3.0 Techniques
/ Calibration – Contact straight Beam
3.1 Contact
3.1.1 Straight
beam
3.1.2 Pulse
echo transmission
4.0 Variables
Affecting Test results
4.1
Instrument
performance variations
4.2
Transducer
performance Variations
4.3
Test specimen
variations
4.3.1 Surface
condition
4.3.2 Part
Geometry
4.3.3 Material
Structures
4.4
Personnel
Variations
4.4.1 Skill
level in interpretation of results
4.4.2
Knowledge
level in interpretation of results
5.0 Procedure
5.1
Thickness
Measurement | 
