425 Environmental Testing Procedures
For Whom Intended Test laboratory managers, engineers and technicians. It also helps quality and reliability specialists and acquisition personnel in government and military activities and their contractors. It is designed for personnel in a wide range of industries.
Brief Course Description The course introduces the factors that must be addressed to undertake a meaningful environmental test. The instructor discusses environmental test applications such as product development, reliability, acceptance, qualification, life cycle, fatigue, accelerated, functional, endurance etc. Specific environmental tests including vibration, shock, vacuum, acoustic, thermal, climatic, and accelerated testing are discussed.
For each environmental test area, the basic theory is introduced along with examples of various test applications so that the students can better appreciate the subject matter prior to delving into detailed test equipment, methods, and procedures. For each testing environment, the course discusses key features of test facilities as well as associated test equipment, including instrumentation and fixtures. Students will gain familiarity with specific test practices and procedures, including test levels and durations. This includes reviewing applicable specifications and standards, generating a test plan, and defining test expectations. Options such as test tailoring and deviation from written requirements will be explored.
The course is presented as a series of highly-interactive lecture/discussion sessions. Special-interest discussions are encouraged outside of the regular course sessions.
Diploma Programs This course is required for TTi’s Environmental Engineering Specialist (EES) and Climatic Test Specialist Certificate (CTS) Diploma Programs and is an elective for any other TTi diploma program.
Related Courses For more detail on dynamic test procedures, see Course 116, Fundamentals of vibration for Test Applications. For climatics see Course 230, Climatic Test Procedures.
Prerequisites There are no definite prerequisites. The course is aimed toward individuals involved in a related technical field. Supervisors may contact TTi regarding prospective attendees’ backgrounds and needs.
Text Each student will receive 180 days access to the on-line electronic course workbook. Renewals and printed textbooks are available for an additional fee.
Course Hours, Certificate and CEUs Class hours/ days for on-site courses vary from 14–35 hours over 2–5 days as requested by client. Upon successful course completion, each participant receives a certificate of completion and one Continuing Education Unit (CEU) for every ten class hours.
Click for a printable course outline (pdf).
Course Outline
Chapter 1 - Introduction to Environmental Testing
- Definition and Philosophy
- Environmental Testing, Defined
- More Specific Objectives
- Philosophy
- Caution
- Environment Simulation & Limitations
- Environmental Load Simulation
- Similitude
- Typical Applications of Similitude
- Testing Examples
- Types of Environmental Tests
- Course Focus, Goals
Chapter 2 - Environmental Testing Program
- Development of an Environmental Testing Program
- Environmental Engineering Management Plan
- Product Life Cycle and Environment Definition
- Environmental Test Requirements and Tailoring Criteria
- Defining Test Methods and Alternatives
- Preparing Detailed Environmental Test Plans
- Performing an Environmental Test
Chapter 3 - Environmental Testing Fundamentals
- Categorization of Environmental Tests
- Exploratory or Development Tests
- Lifetime Testing
- Step-Stress Tests
- Fatigue tests
- Qualification (Qual) Testing
- Protoqualification (PQ) Testing
- Acceptance Testing
- Production Tests
- Product Process Verification (PPV)
- Environmental Stress Screening (ESS)
- Re-Testing
- Examples of Different Test Levels/Margins and Durations
- Standards
- Military (MIL) Standards
- Institutional Standards
- Integrated Product or Process Teams (IPTs)
- Relationship between IPT and Tailoring Environmental Test Standards
- Device Under Test (DUT)
- DUT Configuration
- Test Equipment
- Instrumentation
- Test Fixtures
- Sample Fixtures
- Test Facilities
- Capabilities and General Practices
- Infrastructure and Equipment
- Detailed facility and test equipment checklist
- Personnel Roles and Responsibilities
- Plans and Procedures
- Training
Chapter 4 - Introduction to Environmental Test Procedures
- Importance and Limitations of Test Procedures
- Necessity of Standards
- Tailoring Standards
- Contents of a Written Environmental Test Plan
- Test Requirements, Objectives, and Goals
- Description of Device Under Test (DUT)
- Environmental Testing Methods, Levels and Tolerances
- Performance Testing and Pass/Fail Criteria
- Expected Test Results
- Test Equipment and Instrumentation
- Test Facilities
- Detailed Test Procedures
- High-level Test Procedure Topics
- Sample Shock Test Procedure
- Documentation and Reporting
Chapter 5.1 - Vibration Theory
- Degrees of Freedom
- Mathematical Treatment of Vibration Forced Vibration
- Transmissibility
- Damping
- Isolation
- Random Vibration
- Definitions
- Spectral Density
- Calculating RMS
- Applications of Vibration Testing
Chapter 5.2 - Vibration Test Equipment
Chapter 5.3 - Vibration Test Procedures
- Modal Testing and Analysis
- Sine Vibration Testing
- Closed Loop Control
- Sweep Rates
- Resonant Search
- Fixture Evaluation
- Random Vibration Testing
- Equipment Operation
- Severities
- Tolerances
- Control Options
- Test Set-up, Preparation, Procedures
- Failure Criteria
- Types of Vibration tests, Combinations
- Force-limited testing
Chapter 6.1 - Mechanical Shock Theory
- Shock Basics
- What is Mechanical Shock?
- The Impact of Shock
- Classifications of Shocks
- Classical Shocks
- Characteristics of a Classical Shock Test
- Classical Shock Signal
- Complex Shocks
- Pyroshock
- Measuring and Analyzing Mechanical Shock
- Shock Response Spectrum
- Shock Response Spectrum Shapes
Chapter 6.2 - Mechanical Shock Test Equipment
- Shock Apparatuses and Instrumentation
- Drop Test Machines
- Low Impact Free-fall Shock Test Machines
- Low Impact Pneumatic Shock Machine
- Low Impact Machines, Arrestors
- High Impact Pendulum Impact Machines
- High Impact Sled Impact Machine
- Resonant Table
- Hopkinson Bar
- Pyroshock
- Spring-loaded Impact Hammer
- Electrodynamic Shaker Table
- Hydraulic Shaker Table
- Large-Scale Navy Explosive Shock Testing
- Ballistic Shock Testing
- High Velocity Shock Crash Testing
- Instrumentation: Accelerometers for Shock Testing
- Data Acquisition and Instrumentation References
Chapter 6.3 - Mechanical Shock Test Procedures
- General Information
- Reasons to perform shock tests
- Types of shock testing and choice of procedures
- Testing Preparation
- Testing: Common themes and required information
- Testing parameters and tolerances
- Control strategy
- Condition of DUT
- Subsystem Testing, Load Factor
- Preconditioning, Initial Checks, Calibration
- Sample Shock Test Procedures
- Functional
- Transit Drop
- Bench Handling
- Crash Hazard
- Rail Impact
- Pyrotechnic
- Protective Packaging & Damage Boundary Graph
Chapter 7 - Acoustic Environmental Testing
- Acoustic Theory and Applications
- Sound
- Facts About Sound
- Human Hearing
- Noise
- Acoustics
- Sound Pressure Level
- Sound Pressure and Sound Power
- Acoustic Testing Applications
- Acoustic Test Equipment
- Generators
- Microphones
- Microphone Selection Criteria
- Acoustic Test Chambers
- Acoustic Test Procedures
- Overview
- Acoustic Testing Standards, Resources
- Environmental Acoustic Testing
- Exposure and Survivability Testing
- Acoustic Emissions Testing
- Noise Suppression Tests
Chapter 8 - Vacuum Testing
- Vacuum Theory and Applications
- Early Observation of a Vacuum
- Concept of Pressure
- What is a Vacuum?
- Levels of Vacuum (approximate)
- Vacuum Level versus Application
- Vacuum Applications-Examples
- Vacuum Test Equipment
- Vacuum Pumps in a System
- Roughing Pumps, Overview
- Transition Pumps
- Hi-Vacuum Pumps Overview
- Diffusion Pumps
- Turbomolecular High-Vacuum Pumps
- Cryogenic High-Vacuum Pumps
- Sputter-Ion High-Vacuum Pumps
- Chemisorption/Getter High-Vacuum Pumping Mechanism
- Vacuum Gauges: Classification, Considerstions, Selection
- Bourdon Tube Direct-Reading Gauges
- Diaphragm Gauges
- Double-sided Capacitance Vacuum Gauge
- Pirani Low-Vacuum Indirect-Reading Gauges
- Convection Low-Vacuum Indirect-Reading Gauges
- Thermocouple Low-Vacuum Indirect-Reading Gauges
- Hot Cathode Ionization High-Vacuum Gauges
- Modern Bayard Alpert Ion Gauge
- Cold Cathode Ionization High-Vacuum Gauges
- Vacuum Chambers and Components
- Vacuum Seals: O-Rings
- Face and Circumference ISO O-Ring Seals
- Metal Vacuum Seals
- Conflat or Knife-edge Metal Seal
- Vacuum Seals: Feed-thrus
- Vacuum Test Procedures
- Turbomolecular Vacuum Pump System Operation
- Diffusion Vacuum Pump System Operation
- Ion Vacuum Pump System Operation
- Cryogenic Vacuum Pump System Operation
- Leak Detection Basics
- Sources of Leaks
- Outside-in Vacuum Leak Rate Measurement
- Inside-Out Vacuum Leak Rate Measurements
- Outgassing Basics
Chapter 9.1 - Thermal Theory
- Heat Transfer Process-Three Types
- Flow Directions-Examples of Driving Force
- Conservation of Energy -First Law of Thermodynamics
- Sensible, Latent heat, Heat of Fusion, etc.
- Temperature
- Temperature Scales, Conversions, Absolute Temperature
- Conduction Heat Transfer: Heat Flows Through a Solid
- Convection Heat Transfer
- Radiation Heat Transfer
- Thermal Testing Applications
Chapter 9.2 - Thermal Test Equipment
- Thermal Testing Equipment Overview
- Heaters and Chillers
- Liquid Heaters and Coolers
- Typical Liquid Heater/Cooler System Block Diagram
- Thermoelectric Heaters/Coolers
- Heat Pipes
- Heat Pipes Application Example
- Temperature Sensors Overview
- Temperature Sensor Advantages and Disadvantages
- Thermocouples
- Thermocouple Measurement Procedure
- Thermocouple Examples
- Resistance Temperature Detector (RTD)
- RTD Construction, Examples
- Thermistor
- Liquid Crystal Temperature-Sensitive Films
- IR Sensors
- IR Temperature Sensors
- Thermal Test Chambers and Systems
- Thermal Atmosphere, Altitude, and Humidity Chambers
- Thermal-Vacuum Chambers
- Thermal Cycling Chambers
- Thermal-Shock Chambers
- Thermal Vibration Chambers
Chapter 9.3 - Thermal Test Procedures
- Environmental Thermal Tests
- Military or Institutional Standards
- Types of Thermal Tests
- Testing Atmosphere
- Atmosphere, Altitude and Vacuum
- Thermal Cycling
- Objectives, Measurements, Procedures
- Thermal Balance
- Description, Objectives, Measurements
- Thermal Shock
- Description, Objectives, Measurements
Chapter 10 - Additional Climatic Testing Procedures
- Solar Radiation Testing:
- Source, Scope, Limitations, Content and Tailoring
- Types of Solar Exposure Tests
- Solar Test Conditions, Levels, and Durations
- Temperature and Radiation Flux Charts
- Spectral Power Distribution
- Equipment for Laboratory Solar Tests
- Solar Testing Procedures
- Rain Testing:
- Source, Scope, Limitation, Test Content and Tailoring
- Types of Exposure Tests, Conditions, Levels, and Durations, Equipment
- Rain and Exaggerated Rain Environmental Chambers
- Water Drip Environmental Chamber Setup
- Rain Testing Procedures
- Humidity Testing
- Source, Scope, Limitations, Types of Exposure Tests, Conditions, Levels, Durations
- Temperature-Humidity Exposure Cycles I and II
- Humidity Testing Equipment: Chamber, Instrumentation, Control System
- Humidity Testing Procedures
- Salt Fog Testing
- Source, Scope, Limitations, Content and Tailoring, Equipment, Testing Procedures
- Sand and Dust Testing
- Source, Scope, Content and Tailoring, Equipment, Procedures
- Sand and Dust Test Chambers
- Sand and Dust Test Procedures
Chapter 11 - Accelerated Testing
- Reducing Test Time
- Test Assumptions
- The Accelerated Test
- What Does an Accelerated Test Accelerate?
- Can Accelerated Testing Do What is Expected?
- Which Environmental Forcing Functions Are Best?
- Different Environments Produce Different Effects
- Different Rates of Test Acceleration
- How Much Acceleration should be Expected?
- Are Accelerated Tests Always Shorter?
- Critical Aspects of Accelerated Test Models
- Accelerated Test Models
- Accelerated Testing is Not Risk-Free
- Miner’s “Rule” Cautions
- The Basic Principles of Test Time Compression
- Two Types of Test Acceleration
- Higher Frequency of Occurrence
- Exaggerate Load Levels
- Accelerated Test Cautions
Appendix C5 - Class Exercise—Random Vibration Testing of a Spacecraft Instrument
Appendix C8 - Vacuum Testing Background Information
- Mass Spectrometers
- Leak Rate Measurements
- Outgassing Measurement Techniques
- TML & CVCM Outgassing Procedures
- Vacuum Pressure Change (VPC) Technique
- Reference Sources for Vacuum
Appendix C9 - Thermal Testing Background Information
- Thermocouples
- Color Codes
- Wire Grades, Types
- Thermocouples in Use
- IR Sensor Operation
- Emissivity, ε
- IR Sensor Applications, Considerations
- IR Cameras
Summary
Final Review
Award of Certificates for Successful Completion
Click for a printable course outline (pdf).