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CTS PrepPart One
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Certified Technology Specialist Professionals
• Know the “big picture” of the AV industry– Disciplines within the AV industry– Allied industries– AV project cycle
• Know the technical scope of general projects
Ch 1
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Disciplines within the AV Industry
ManufacturersSystems
IntegratorsRental & Staging
Companies
IndependentConsultants
Technology Managers
Value-addedDealers
Distributors PresentationProfessionals
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Allied Industries
ArchitecturalArchitecture, Interior
Design, Carpentry
ElectricalPower, Infrastructure,
Lighting
Mechanical/HVACVentilation, Fire Suppression
StructuralStructural Engineering, Rigging,
Seismic
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The AV Project Cycle
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Technical Scope of General Projects• Boardroom• Auditorium• Training room• Divisible conference room
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Questions?
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Part One
• Domain A: Creating AV Solutions – Gather Information– Needs Analysis– Site Survey– Maintain Awareness of Changes
& Create Scope– Determine AV Solution
Components
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Gather Information
• Determine what the customer wants
• Obtain scale drawings• Obtain customer
budget • Obtain customer
constraints (work hours, noise levels, cultural issues)
Ch 11
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Domain A: Creating AV Solutions
Gather Information• Needs Analysis• Site Survey• Maintain Awareness of
Changes & Create Scope• Determine AV Solution
Components
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Needs Analysis
• What is a needs analysis?• Why is it important?
Ch 11 – Pg 191
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Needs Analysis
• What information is needed?– Determine what the customer wants – Obtain scale drawings– Obtain customer budget – Obtain customer constraints (work hours, noise levels,
cultural issues)
• Determine the end user’s needs by determining the following.– The required application(s) based on the user’s needs– The tasks and functions that support the application– The wishes and desires of the end-user
Ch 11 – Pg 191
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Gather Information
• Needs Analysis Exercise– Facts to be conveyed.– How to be conveyed.– How it takes shape.
Remember! No equipment
discussions!Ch 11
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Domain A: Creating AV Solutions
Gather InformationNeeds Analysis• Site Survey• Maintain Awareness of
Changes & Create Scope• Determine AV Solution
Components
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Evaluate Site Environment
• Site Survey Exercise
Ch 12 and 13
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Domain A: Creating AV Solutions
Gather InformationNeeds AnalysisSite Survey• Maintain Awareness of
Changes & Create Scope• Determine AV Solution
Components
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• Exercises– Maintain Awareness of Changes
• Review potential changes in Chapter 14 of the CTS Exam Guide, Second Edition
– Individually Develop a Functional AV Scope• Review the example of a scope in your student binders• Write a brief scope of you group’s project.• Present findings to contact (designated student) of the
recommendations.
Maintain Awareness of Changes, Develop a Functional AV Scope Exercises
Ch 14 and 15
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Domain A: Creating AV Solutions
Gather InformationNeeds AnalysisSite SurveyMaintain Awareness of
Changes & Create Scope• Determine AV Solution
Components
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Determine AV solution components• Room Features• View-ability• Aspect Ratio • Projection Throw • Viewing Parameters• Audio• Project Documentation
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Rooms Features
• Space for Presenter and Equipment• Location of Equipment• Space for the Audience• Accessibility to the Room• Accessibility to the Equipment• Control Room Size• Rear Projection Room Size• Doors• Finishes within the Room
Ch 14
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Image View-ability Factors
• Size• Shape• Target of vision (screen)• Obstructions• Brightness• Contrast
Ch 5 and 14
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Aspect Ratio
• Width dimension of a picture expressed relative to the height dimensions.
• The aspect ratio of all broadcast composite video systems is 4 units wide by 3 units high , also written as 4:3 and 1.33 (analog).
• The aspect ratio of HD can be 16 units wide by 9 units high also written as 16:9 and 1.78
Ch 5 – Pg 99
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Aspect Ratio Exercises
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Determine AV solution componentsRoom FeaturesView-abilityAspect Ratio • Projection Throw • Viewing Parameters• Audio• Project Documentation
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Projection Throw
• Projection Optics• Keystone• There are three dimensions to projector placement - all in
relationship to the desired image dimensions and location• Use projector manual to determine location• Calculate Projection Throw Exercise
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Determine AV solution componentsRoom FeaturesView-abilityAspect Ratio Projection Throw • Viewing Parameters• Audio• Project Documentation
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Viewing Parameters
• Perception Limitations• Viewing requirements of the Task• Text Size (or detail) to be displayed• Viewing Distances• Image (and hence screen) Height• Aspect Ratio of Image
:
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Determining Image Size
• The maximum viewing distance is based on the amount of detail we need to see in the image, not the resolution of the image.
• What is the Task?– To View: General Viewing– To Read: Detail Viewing with Clues (like this
slide)– To Inspect: Detail Viewing without Clues
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Reading (With Clues)
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Inspection (No Clues)
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Determining Image Size
• Rules of Thumb: Image height equals the distance to the furthest viewer divided by:– 8 for General Viewing Tasks, – 6 for Detailed Viewing Tasks, or – 4 for Inspection Viewing Tasks.
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Required Image Height
• Furthest Viewer is 24 feet away. • What is the image height for:
– General Images? – Detailed Images?– Inspection Images?
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Required Image Height
• Furthest Viewer is 32 feet away. • What is the image height for:
– General Images?– Detailed Images?– Inspection Images?
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Character Height
height
Maximum of 150 x height
General Rule
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Nearest Viewer
• How Close Can the Nearest Viewer Be? • The correct answer is?
– The Image Width
• First Row -- No closer to the Image than the width of the IMAGE
Image Width I.W.
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Nearest Viewer
• How Close Can the Nearest Viewer Be?• An additional criterion is based on the
vertical angle of view
15° Max to Center of Image if possible.
0
30° Max to Top of Image if possible.
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Viewing Area
• Where should the seats be (and where should they not be) for the image to be useful to the entire audience based on the required tasks?
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Viewing Angles
180 Viewing Angle 90 Viewing Angle
On Axis
45° 45°
On Axis
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Defining the Viewing Area
• The best viewing is on axis to the image.• The maximum off-axis viewing angle will
be dependent on the characteristics of the screen.
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Defining the Viewing Area
• The widest viewing angles are provided by:– Direct-view displays– Matte white front projection screen material – Diffusion rear projection screens
• High-gain projection screens can limit viewing angles
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Defining the Viewing Area
• The “good” viewing area is within 45 degrees of the projection axis or within a 90 degree viewing cone.
90
45
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Defining the Viewing Area
• The “acceptable” viewing areas are within 45 degrees of the edge of the image
45
45
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Determine AV solution componentsRoom FeaturesView-abilityAspect Ratio Projection Throw Viewing Parameters• Audio• Project Documentation
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Audio
• Types of Audio Systems • Speech Reinforcement (also: “Mix-Minus”)• Program Playback• Paging• Background Music• Noise Masking• Audio conference (also: Audio for VTC )
Ch 4 and 16
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Speech Reinforcement System
• In order to work properly, a sound system must do three things:– It must be Loud Enough– It must be Intelligible– It must remain Stable
Ch 16 – Pg 310
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Loud Enough
• Achieves target level– 25 dB signal to noise
• Same level to all ears +/- 3 dB• No perceived distortion (<1% THD)• Adequate electrical signal to noise
(>60dB)
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Intelligible
• Good direct to reflected (reverberant) ratio• Meets desired frequency response
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Stable
• Allows sufficient gain before feedback with headroom
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Ohm’s Law
• Expresses the relationships between Voltage, Current and Resistance in an electrical circuit
• Helps calculate the Power in a circuit– if you know any 2 values, you can find the third one.
Appendix C – Pg 546
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Ohm’s Law
Appendix C – Pg 546
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Ohm’s Law Example
LOAD100 ohmsR
VOLTAGESOURCE
100V
+-
Appendix C – Pg 546
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• Expressed in amps by the symbol I• The flow of electrons in a circuit• In a DC circuit the flow is in one direction
only (minus to plus?)• In an AC circuit the flow reverses
periodically.
I=V/R
Current
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Voltage
• The force that causes the electrons to flow.• Expressed in Volts or V (or E)• Mic level is 0.001 - 0.003 V (1 – 3 mV)• Line level is 0.3V (semipro) or 1.23 V(pro)• Loudspeaker level is 4 V or more
V=I * R
Appendix C – Pg 546
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Resistance
• The opposition to the flow of electrons• Expressed in ohms and R• Applies to DC (like from a battery).
R=V/I
Appendix C – Pg 546
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Impedance
• Like resistance, but applied to Alternating Current. (Audio signals, radio signals, the power from the wall)
• Expressed in ohms and Z
• Important for loudspeakers, power amps, and connecting the inputs and outputs of equipment.
Ch 9 – Pg 161-164
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Audio Systems
• Loudspeakers have a characteristic impedance
• Impedance is the opposition to alternating current flow
• A common loudspeaker has an impedance of 4, 6 or 8 Ω
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Power
• The work done by the flow of current• Measured in watts
P = V*I
Appendix C – Pg 546
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Ohm’s Law Exercise
PowerAmp
100w 8 ohms
Calculate the current and voltage in this circuit
Appendix C – Pg 546
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Loudspeakers Wired in Series• Total Impedance (Z) = Z1 + Z2 + Z3…
• If you have 4 loudspeakers, each rated at 4 ohms…
• Z = 4 + 4 + 4 + 4• Z = 16 ohms
• Therefore, an amplifier that is rated for a 16 ohm load would be the best choice. An amp optimized for a 4 ohm load could not couple energy efficiently to this circuit of loudspeakers.
Ch 16 – Pg 321-323
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Loudspeakers Wired in ParallelFormula for parallel resistance and
impedance 1
ZT = 1 1 1 1
Z1 Z2 Z3 … ZN
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Loudspeakers Wired in a Series Parallel Circuit
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Audio Systems• Amplifiers have an output impedance they are
expecting to have connected to their output terminals
• Matching this output impedance with the loudspeaker load maximizes energy transfer from amplifier to loudspeaker to acoustic energy
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Audio Systems
• A transformer added to a loudspeaker will increase the impedance of that loudspeaker to the amp
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Constant Voltage
Ch 16– Pg 323 - 325
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The Decibel
• Expresses sound and signal levels in a way that is easier to work with and closer to the way we experience them.
• Comes in two basic flavors:– 1 – Power– 2 – Voltage/Pressure/SPL
Appendix C – Pg 545
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Power Decibels Exercise
• dB=10 * log (P1/P2)
P1 is the power change (to) value
P2 is the power reference (from) value
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Distance and Voltage Decibels Exercise
• dB=20 * log (D1/D2)
• dB=20 * log (V2/V1)
D1 or V1 is the reference (from) value
D2 or V2 is the change (to) value
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Loudspeaker Directivity
• The angle over which a speaker radiates• Usually shown on a plot• Dispersion pattern varies with frequency
Ch 5, Pg 64-65
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Loudspeaker Directivity
Ch 5, Pg 64-65
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50% Overlap (center-to-center)
• Pros– Excellent coverage at most
frequencies (1.2 dB variation)
• Cons– Costly– Maybe coverage is better than
required– Negative interaction from nearby
loudspeakers– Adds too much acoustical energy to
space
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Edge-To-Edge
• Pros– Acceptable coverage at main speech
frequencies (5.4 dB variation)– Inexpensive– Minimum interaction of loudspeakers
with each other and room
• Cons– May have uneven frequency response– May have some low spots in corners
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Partial Overlap• Pros
– Very good coverage at most frequencies(2.6 dB variation)
– Good middle-of-the road design– Ensures few or no low spots
• Cons– May not be as even in frequency
response– Some negative interaction from
nearby loudspeakers– Adds some acoustical energy to space
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Determine AV solution componentsRoom FeaturesView-abilityAspect Ratio Projection Throw Viewing ParametersAudio• Project Documentation
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Project Documentation
• Contract Documents• Project Drawings• Project Specifications
Ch 15 and 16
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AV Project Drawings
• Riser Diagrams• Block Diagrams• Plate Details• Panel Layouts• Equipment Rack Layouts• Details• Shop & Submittal Drawings
Ch 15 and 16
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Types of Drawings
• Index• Notes• Floor Plans• Reflected Ceiling Plans• Sections• Elevations• Details
Ch 12 – Pg 216-230
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Reading Blueprints
• Orientation Schedules• Notes• Abbreviations• Symbols/Icons
Ch 12 – Pg 216-230
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Reading Blueprints - General
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Abbreviations
• AFF Above Finished Floor• AFP Above Finished Platform or Raised
Floor• AS Above Slab• CL Center Line• DIA Diameter• DR Door• E East
CL
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Abbreviations
• EC Empty Conduit• (E) Existing• EL Elevation• ELEC Electrical• MISC Miscellaneous• NIC Not In Contract• NTS Not To Scale• OC On Center• OD Outer Diameter
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Abbreviations
• OFCI Owner Furnished Contractor Installed
• OFOI Owner Furnished Owner Installed• RCP Reflected Ceiling Plan• SECT Section• UBC Uniform Building Code• VIF Verify In Field
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Scales
• It would be difficult to draw at full size so things are “scaled down”
• 1/4 and 1/8 typical• Other Scales for Details
0 1’ 10’
1/4” = 1’- 0”
1’ 5’ 10’
20’0
1/8” = 1’- 0”
Ch 12 – Pg 226 - 228
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Floor Plans
• Slice through the building at 4 feet above the floor
Ch 12 – Pg 217
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Reflected Ceiling
• Ceiling Grid• Diffusers• Fluorescent Lights• Down Lights• Sprinklers• Projection System• Loudspeakers
Ch 12 – Pg 217
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Reflected Ceiling Plans• The floor is a mirror
S
S
S SS
S
S
SS
S
S
Ch 12 – Pg 217
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Symbols/Icons
• Every Project has different symbols and icons.
• As long as they are defined in a key or legend, the actual object does not matter.
Ch 12– Pg 228
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Symbols/Icons
• Column Lines• Orient point of circles to column line.
Letters in one direction. Numbers in the other direction. Also shows as a grid on drawing.
1
A
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Symbols/Icons
• Match Lines• Shaded portion is the side considered
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Symbols/Icons
• Elevation Flags• D1, 2, 3 and 4 : Elevation Identification• A4.0 : Drawing where elevation drawn
D4
A4.0 D1
D2
D3
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Symbols/Icons
• Section Cuts
Top # : Section Identification
Bottom # : Drawing where section is drawn
D1
A3.0
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Sections
• Cut through the room you are working in -- just like cutting an orange
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Sections
A3.0D2
A3.0D1
A3.0D2
A3.0D1
A3.0D4
A3.0D4
A3.0D3
A3.0D3
A3.0D5
A3.0D5
Ch 12 – Pg 221
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Section 1• Straight to the north at CL
A3.0D1 Section D1-D1
Ch 12 – Pg 221
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Symbols/Icons
• Detail Flags
A5.625
Top # : Detail Information
Bottom # : Drawing where detail is drawn.
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Details
• Small items that need to be blown up to show how they need to be installed.
• Too small to draw or see at the project’s typical drawing scale.
Ch 12 – Pg 221
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Video Projector Detail
VIDEO PROJECTOR MOUNTING DETAIL
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Determine AV solution componentsRoom FeaturesView-abilityAspect Ratio Projection Throw Viewing ParametersAudioProject Documentation
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Design AV Solution Exercise
• Create specifications• Create bill of materials (BOM)• Design a floor elevation• Develop block diagram
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Domain A: Creating AV Solutions
Gather InformationNeeds AnalysisSite SurveyMaintain Awareness of
Changes & Create ScopeDetermine AV Solution
Components
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CTS Prep Homework
• Homework: Sample exam – Self score• Homework: Complete CTS self-assessment
checklist• Use the information from the self
assessment and exam to determine self-directed breakouts.