Introduction
High-temperature environments can significantly affect product reliability.
When exposed to elevated temperatures, electronic components may experience parameter drift, accelerated aging, material degradation, thermal expansion, insulation deterioration and unexpected functional failures.
For products used in automotive, consumer electronics, industrial automation, telecommunications and energy systems, verifying high-temperature performance is an essential part of environmental reliability testing.
IEC 60068-2-2:2025 — Environmental testing — Part 2-2: Tests — Test B: Dry Heat provides standardized methods to evaluate whether components, equipment and other products can withstand controlled dry heat conditions during operation, transportation or storage.
However, selecting a suitable dry heat test chamber requires more than asking:
“Can the chamber reach +150°C?”
A reliable IEC 60068-2-2 test setup should consider:
- Product type and application
- Heat dissipation characteristics
- Operating condition
- Required temperature and exposure time
- Specimen stabilization
- Airflow condition
- Heat load
- Working space
- Temperature monitoring
This guide explains IEC 60068-2-2 dry heat testing, including test methods, temperatures, procedures, chamber requirements and how to select the right environmental test chamber for different product applications.
Updated for IEC 60068-2-2:2025 — Test B: Dry Heat
IEC 60068-2-2 Dry Heat Test: Quick Overview
Before selecting a chamber, engineers should first understand what the standard evaluates.
| Item | Description |
|---|---|
| Standard | IEC 60068-2-2 |
| Test Type | Dry Heat Environmental Testing |
| Main Purpose | Evaluate product reliability under high-temperature conditions |
| Applicable Products | Electronics, automotive components, industrial equipment, energy systems |
| Typical Temperatures | +55°C to +150°C |
| Main Equipment | Dry Heat Test Chamber / High Temperature Test Chamber |
| Main Considerations | Temperature stability, airflow, specimen heat load and working space |
IEC 60068-2-2 is not a product certification standard for one specific industry.
Instead, it provides a standardized environmental test method that can be referenced by:
- Product specifications
- Customer requirements
- Reliability qualification programs
- Internal validation procedures
The actual test condition depends on the product and application.
For example:
An automotive ECU and a passive connector may both use IEC 60068-2-2, but they may require completely different:
- Temperature levels
- Exposure duration
- Operating conditions
- Chamber configurations
What Does IEC 60068-2-2 Evaluate?
IEC 60068-2-2 evaluates whether a specimen can maintain its required performance when exposed to controlled dry heat conditions.
Typical evaluation objectives include:
High-Temperature Operation
Can the product continue functioning when the surrounding temperature increases?
Examples:
- Automotive ECU inside an engine compartment
- Industrial controller in a factory environment
- Communication equipment installed outdoors
High-Temperature Storage
Can the product survive transportation or storage under elevated temperatures?
Examples:
- Electronic assemblies stored in warehouses
- Products transported through hot climates
- Packaged components
Thermal Reliability
Can the materials, components and assemblies maintain their mechanical and electrical performance after heat exposure?
Examples:
- Plastic housings
- Seals
- Connectors
- PCB assemblies
Which Products Require IEC 60068-2-2 Dry Heat Testing?
IEC 60068-2-2 is widely used in industries where products may experience elevated temperatures during their service life.
The standard is especially relevant for products containing:
- Electronic components
- Control circuits
- Batteries or energy systems
- Precision assemblies
- Temperature-sensitive materials
Typical applications include:
| Industry | Typical Products | Main Reliability Concerns |
|---|---|---|
| Consumer Electronics | Smartphones, tablets, cameras, chargers, wearables | Battery performance, display stability, component reliability |
| Automotive Electronics | ECU, sensors, lighting modules, controllers | High-temperature operation, electrical reliability |
| Semiconductor & Electronics | PCB, IC modules, connectors, relays | Component aging, electrical drift |
| Industrial Equipment | PLC, HMI, power supplies, control systems | Continuous operation under heat |
| Telecommunications | Communication modules, outdoor electronics | Long-term thermal reliability |
| Battery & Energy | BMS, battery electronics, energy systems | Thermal management and control performance |
| Aerospace & High-Reliability Electronics | Sensors, control assemblies | Extreme environmental durability |
Dry Heat Testing vs Real-World Applications
A dry heat test is not only about exposing a product to a high temperature.
The purpose is to reproduce the thermal stress that a product may experience during actual use.
For example:
Automotive Electronics
An ECU may experience:
- High ambient temperature
- Continuous operation
- Internal heat generation
- Limited cooling conditions
A dry heat test helps evaluate:
- Startup performance
- Communication stability
- Electrical function
- Component reliability
Industrial Controllers
Industrial equipment may operate:
- Near machinery
- Inside electrical cabinets
- In factories with elevated ambient temperatures
Testing helps verify:
- Long-term operation
- Control stability
- Thermal design
Battery Electronics
Battery-related electronics may require evaluation of:
- Thermal management
- Control reliability
- Electrical stability
For higher-risk battery testing, additional safety considerations may be required.
What Failures Can Dry Heat Testing Identify?
A major value of IEC 60068-2-2 testing is identifying potential failures before products enter the market.
High-temperature exposure can reveal weaknesses that may not appear during room-temperature testing.
1. Material Softening and Aging
Elevated temperatures accelerate material degradation.
Common affected materials include:
- Plastics
- Rubber seals
- Adhesives
- Insulation materials
Possible failures:
- Housing deformation
- Seal failure
- Reduced mechanical strength
- Loss of protection performance
Typical products:
- Consumer electronics
- Automotive components
- Industrial assemblies
2. Electrical Performance Drift
Temperature changes can affect electrical characteristics.
Possible issues:
- Resistance variation
- Signal instability
- Sensor accuracy drift
- Increased leakage current
Common products:
- Sensors
- PCB assemblies
- Electronic controllers
3. Thermal Expansion Stress
Different materials expand at different rates.
Examples:
- Metal terminals
- Plastic housings
- PCB substrates
- Solder joints
Repeated or prolonged heat exposure may cause:
- Connection problems
- Mechanical stress
- Assembly deformation
4. Thermal Management Problems
Powered products generate internal heat.
Examples:
- ECU
- Power modules
- Controllers
- Communication equipment
A product may pass normal-temperature testing but fail under high-temperature conditions because:
- Cooling margin is insufficient
- Internal temperature increases excessively
- Heat cannot dissipate effectively
5. Accelerated Reliability Degradation
Higher temperatures accelerate many aging mechanisms.
Dry heat testing helps engineers identify:
- Weak components
- Poor thermal design
- Material limitations
- Reliability risks
before mass production.
IEC 60068-2-2 Test Methods: Bb, Bd and Be
The correct dry heat test method depends on how the specimen behaves during testing.
The key question is:
Does the specimen generate significant heat during operation?
A passive connector and a powered electronic controller experience very different thermal conditions inside a test chamber.
IEC 60068-2-2 therefore distinguishes between:
- Non-heat-dissipating specimens
- Heat-dissipating specimens
- Energized specimens
Test Bb — Dry Heat for Non-Heat-Dissipating Specimens
Test Bb applies to specimens that do not generate significant heat during the test.
Typical examples:
- Passive components
- Connectors
- Materials
- Mechanical parts
- Unpowered electronic assemblies
For these applications, the chamber mainly needs to provide:
- Accurate temperature control
- Stable temperature distribution
- Reliable exposure conditions
Because the specimen does not significantly affect the chamber environment, the chamber air temperature is the main thermal reference.
Test Bd — Dry Heat for Heat-Dissipating Specimens
Test Bd applies to specimens that generate heat during operation.
Typical examples:
- Controllers
- Industrial electronics
- Communication equipment
- Powered assemblies
For these applications, chamber selection becomes more complex.
Engineers should consider:
- Specimen heat generation
- Airflow condition
- Temperature measurement location
- Stabilization time
- Chamber capacity
A chamber display showing:
+85°C
does not automatically mean the powered specimen itself is at +85°C.
The actual specimen temperature depends on:
- Internal heat generation
- Product design
- Cooling path
- Air movement
Test Be — Heat-Dissipating Specimens Energized Throughout
Test Be is intended for specimens that remain powered throughout the test.
Typical examples:
- Automotive ECU
- Battery management electronics
- Power modules
- Industrial controllers
During the complete test period, the chamber must:
- Maintain the required temperature
- Remove specimen-generated heat
- Maintain stable conditions
- Support continuous operation monitoring
This creates an important equipment-selection question:
Can the chamber maintain the required dry heat condition while the specimen is operating?
How to Select the Correct IEC 60068-2-2 Test Method?
Selecting the correct IEC 60068-2-2 test method should begin with understanding the specimen, not choosing a chamber model.
The main questions are:
- Does the specimen generate significant heat?
- Is the specimen powered during the test?
- Will the specimen remain energized throughout the exposure period?
The answers determine whether the test should follow:
- Test Bb
- Test Bd
- Test Be
IEC 60068-2-2 Test Method Decision Process
Step 1 — Does the specimen dissipate heat?
No
The specimen does not generate significant heat.
Examples:
- Connectors
- Passive components
- Materials
- Unpowered assemblies
↓
Test Bb
Yes
The specimen generates heat during operation.
Examples:
- ECU
- Controller
- Power electronics
- Communication equipment
↓
Continue evaluation.
Step 2 — Is the specimen energized throughout the test?
No
The specimen is powered after temperature stabilization.
↓
Test Bd
Yes
The specimen remains powered during the complete test.
↓
Test Be
For heat-dissipating specimens, the chamber configuration should additionally consider:
- Specimen heat load
- Airflow condition
- Working space
- Temperature measurement points
- Cable access
- Monitoring requirements
Engineering Note
A chamber temperature display only shows the chamber condition.
For powered specimens:
Chamber Temperature ≠ Specimen Temperature
The final product temperature depends on:
- Internal power consumption
- Product thermal design
- Heat transfer path
- Air circulation
IEC 60068-2-2 Dry Heat Test Procedure
Although the exact procedure depends on the selected method, a practical dry heat test normally follows a sequence from requirement definition to final evaluation.
Define the Test Requirement
Before starting the test, engineers should define:
- Specimen type
- Test temperature
- Exposure duration
- Operating condition
- Functional monitoring requirements
- Acceptance criteria
The test condition should represent the expected application environment.
For example:
Automotive ECU
Possible requirement:
- +85°C
- Powered operation
- Communication monitoring
- 96-hour exposure
Passive Connector
Possible requirement:
- +125°C
- Non-powered condition
- Material evaluation
Both use IEC 60068-2-2, but the chamber configuration requirements are different.
Install the Specimen
The specimen should be installed according to the test requirement.
Important factors include:
Specimen Clearance
Sufficient space should be maintained between:
- Specimen and chamber walls
- Multiple specimens
- Air inlet and outlet areas
Sensor Placement
Temperature sensors should be positioned according to the test requirement.
Possible monitoring points include:
- Specimen surface
- Internal temperature point
- Critical component location
Cable and Connection Arrangement
Powered tests may require:
- Power cables
- Communication cables
- Monitoring cables
- External measurement equipment
Therefore, cable ports and access design are important chamber considerations.
Controlled Temperature Increase
The chamber temperature is increased toward the specified dry heat condition.
Unlike thermal shock testing, IEC 60068-2-2 focuses on controlled high-temperature exposure.
The purpose is to evaluate product behavior under a stable elevated temperature environment.
Specimen Stabilization
This is one of the most important practical considerations.
A common mistake is assuming:
The chamber reaches the target temperature, so the test has started.
This may not be correct.
The chamber may display:
+125°C
while the actual specimen temperature is still increasing.
The stabilization time depends on:
- Specimen size
- Material properties
- Internal structure
- Heat generation
- Installation arrangement
Examples:
A small connector may stabilize quickly.
A large powered controller may require significantly more time.
Engineering Note
For reliable IEC 60068-2-2 testing:
Setpoint Reached ≠ Specimen Stabilized
The exposure period should begin according to the test requirement, not simply when the controller reaches the programmed temperature.
Dry Heat Exposure
After the specimen reaches the required condition, the dry heat exposure period begins.
During exposure, engineers may monitor:
- Electrical performance
- Current consumption
- Communication status
- Internal temperature
- Mechanical operation
- Alarm conditions
For powered products, continuous monitoring is especially important.
Examples:
ECU Testing
Monitor:
- CAN communication
- Operating status
- Power consumption
Industrial Controller Testing
Monitor:
- Control output
- System response
- Error alarms
Recovery and Final Evaluation
After completing the exposure period, the specimen is returned according to the specified recovery condition.
Final evaluation may include:
- Visual inspection
- Electrical testing
- Functional verification
- Mechanical inspection
Some failures may appear only after recovery.
Examples:
- Material deformation
- Seal damage
- Connection degradation
- Electrical drift
What Temperature Is Used for IEC 60068-2-2?
IEC 60068-2-2 does not define one universal temperature for every product.
The required dry heat severity depends on:
- Product application
- Expected operating environment
- Customer specification
- Reliability requirements
Common dry heat test temperatures include:
Temperature Typical Application +55°C General environmental exposure +70°C Consumer and industrial products +85°C Automotive electronics +100°C Industrial equipment +125°C High-temperature electronics +150°C Special high-temperature applications
Selecting the Correct Temperature
The highest available chamber temperature is not always the best choice.
For example:
A consumer electronics laboratory mainly performing +70°C testing may not need the same configuration as:
- Automotive qualification laboratories
- Battery electronics laboratories
- Aerospace testing facilities
The chamber should match:
Required Test Condition
rather than simply:
Maximum Temperature Capability
How Long Does IEC 60068-2-2 Dry Heat Test Last?
Common exposure durations include:
- 2 hours
- 16 hours
- 72 hours
- 96 hours
The actual duration depends on the product requirement.
A typical dry heat sequence is:
Heating ↓ Specimen Stabilization ↓ Dry Heat Exposure ↓ Recovery
Heating Time vs Exposure Time
These two periods should not be confused.
Example:
A chamber may require 60 minutes to reach +85°C.
The specimen may require another period to stabilize.
The required exposure time starts according to the defined test condition, not simply when heating begins.
IEC 60068-2-2 Dry Heat Chamber Requirements
A suitable dry heat chamber should reproduce the actual test condition, not only achieve a high temperature.
The key question is not:
Can the chamber reach +150°C?
The better question is:
Can the chamber maintain the required temperature while testing this specific specimen?
1. Temperature Range
The chamber must cover the required dry heat condition.
Common applications include:
- +70°C consumer products
- +85°C automotive electronics
- +125°C industrial electronics
- +150°C special applications
Future testing requirements should also be considered.
A chamber selected only for today's requirement may limit future testing capability.
2. Temperature Stability and Uniformity
Reliable dry heat testing requires controlled temperature performance.
Important specifications include:
- Temperature fluctuation
- Temperature uniformity
- Temperature deviation
Poor temperature control may lead to:
- Test variation
- Inconsistent results
- Difficult comparison between samples
3. Working Space
The available chamber volume must consider more than specimen size.
The actual requirement includes:
Specimen Size
Clearance
Air Circulation
Fixtures
Sensors
A properly sized chamber improves:
- Temperature distribution
- Test repeatability
- Loading flexibility
4. Airflow
Airflow affects heat transfer between the chamber environment and specimen.
For heat-dissipating products, airflow becomes part of the test condition.
Higher airflow may:
- Increase heat removal
- Change specimen surface temperature
Lower airflow may:
- Reduce convective cooling
- Change thermal equilibrium
Therefore, airflow should be considered when testing:
- ECU
- Power modules
- Controllers
- Communication devices
5. Specimen Heat Load
Heat load is one of the most important factors for powered dry heat testing.
Example:
10 electronic modules
×
50 W each
=
500 W heat load
The chamber must remove this heat while maintaining the required dry heat condition.
Before selecting a chamber, engineers should evaluate:
- Power consumption per specimen
- Number of specimens
- Operating condition
- Required temperature
6. Monitoring and Access
Modern dry heat testing often requires additional monitoring.
Useful chamber functions include:
- Temperature recording
- External sensor connection
- Cable ports
- Programmable controller
- Data communication
These improve:
- Traceability
- Repeatability
- Test efficiency
How to Select an IEC 60068-2-2 Dry Heat Chamber?
Selecting a dry heat test chamber should start from the test requirement, not from the chamber specification sheet.
A common mistake is beginning with:
“We need a +150°C chamber.”
However, the correct selection process should begin with:
- What product is being tested?
- Is the specimen heat-dissipating?
- Will the product operate during the test?
- What temperature and exposure time are required?
- How much heat will the specimen generate?
- How much working space is needed?
The chamber should be configured around the actual test condition.
IEC 60068-2-2 Chamber Selection Process
A practical selection approach:
1. Identify the Specimen
Define:
- Product type
- Dimensions
- Weight
- Quantity
- Installation condition
Examples:
Product Typical Test Concern PCB Assembly Component reliability ECU Powered high-temperature operation Connector Material and contact stability Controller Continuous operation Battery Electronics Thermal management
2. Select the Appropriate Test Method
Based on specimen behavior:
Non-Heat-Dissipating
↓
Test Bb
Heat-Dissipating
↓
Evaluate:
- Powered condition
- Heat generation
- Operating requirement
↓
Test Bd / Be
3. Define Temperature and Exposure
Examples:
Consumer Electronics
+70°C / 72 h
Automotive Electronics
+85°C / 96 h
Industrial Electronics
+100°C or +125°C
Special Applications
+150°C
4. Evaluate Operating Condition
The chamber configuration changes depending on whether the specimen is:
- Non-powered
- Powered after stabilization
- Powered throughout the test
Powered tests require additional consideration of:
- Heat load
- Cable access
- Monitoring
- Airflow
5. Calculate Specimen Heat Load
For powered products:
Example:
5 ECUs
×
80 W
=
400 W
The chamber must compensate for this heat while maintaining the required temperature.
6. Select the Chamber Configuration
The final configuration should consider:
- Temperature range
- Temperature stability
- Working volume
- Air circulation
- Heat compensation capability
- Safety requirements
Product → Test Condition → Chamber Solution Matrix
A dry heat chamber should be matched to the product application.
Product Application Typical IEC 60068-2-2 Condition Main Consideration Suggested Solution PCB Assembly +85°C, non-powered Temperature stability GDW Passive Connector +125°C storage Material reliability GDW Automotive ECU +85°C powered Heat load and monitoring GDW / GDJS Industrial Controller +100°C continuous operation Long-term stability GDJS Communication Module +70°C to +85°C operation Functional monitoring GDJS Battery Electronics High temperature with safety concern Safety protection ITM-DEP This approach prevents a common purchasing problem:
Selecting a chamber based only on temperature range while ignoring the actual specimen behavior.
ITM-LAB IEC 60068-2-2 Dry Heat Testing Solutions
ITM-LAB provides environmental test chamber solutions for different IEC 60068-2-2 dry heat applications.
The appropriate configuration depends on:
- Product type
- Temperature requirement
- Operating condition
- Heat load
- Safety requirements
Solution 1 — GDW High & Low Temperature Test Chamber
Best For:
Temperature-only environmental testing
Typical applications:
- Electronic components
- PCB assemblies
- Sensors
- Connectors
- Automotive components
- Industrial parts
GDW is suitable when laboratories require:
- IEC 60068-2-2 Dry Heat testing
- IEC 60068-2-1 Cold testing
without humidity control.
Typical advantages:
- Wide temperature range options
- Stable temperature control
- Multiple chamber capacities
- Suitable for component and assembly validation
For non-powered dry heat testing, GDW provides a controlled high-temperature environment for repeatable testing.
Solution 2 — GDJS Programmable Temperature & Humidity Test Chamber
Best For:
Multi-environment reliability testing
Many laboratories require more than dry heat testing.
The same product may need evaluation under:
- Cold
- Dry heat
- Damp heat
- Temperature and humidity conditions
GDJS combines:
- Temperature control
- Humidity control
and provides a broader environmental testing platform.
Typical applications:
- Automotive electronics
- Consumer electronics
- Industrial equipment
- Electronic modules
Applicable environmental programs may include:
- IEC 60068-2-1 Cold
- IEC 60068-2-2 Dry Heat
- IEC 60068-2-30 Damp Heat
- IEC 60068-2-78 Damp Heat
For laboratories building a complete environmental reliability capability, GDJS can reduce the need for multiple separate systems.
Solution 3 — ITM-DEP Explosion-Proof High Temperature Chamber
Best For:
Battery and higher-risk applications
Battery-related products require additional safety consideration.
Depending on:
- Battery chemistry
- Capacity
- Charging condition
- Discharging condition
- Test objective
additional safety functions may be required.
Explosion-proof environmental chambers can be configured with safety features such as:
- Reinforced chamber structure
- Pressure relief
- Smoke detection
- Fire protection systems
- Safety monitoring
The correct configuration should always be determined according to the specific battery test risk assessment.
Practical Example: Automotive ECU Dry Heat Test
A common IEC 60068-2-2 application is automotive ECU validation.
Assume a laboratory needs to test:
Parameter Requirement Product Automotive ECU Quantity 6 units Temperature +85°C Operating Condition Powered Power Consumption 40 W/unit Exposure Time 96 hours
Calculate Heat Load
Total heat generation:
6 × 40W
=
240W
The chamber must maintain:
+85°C environment
while continuously removing:
240W specimen heat load
Chamber Selection Considerations
The laboratory should evaluate:
Temperature Capability
Can the chamber maintain +85°C continuously?
Working Space
Can six ECUs be installed with sufficient airflow clearance?
Cable Access
Can power and communication connections be safely introduced?
Monitoring
Can the ECU operation be recorded during the test?
The correct chamber is not selected because:
“It reaches +85°C.”
It is selected because:
“It can maintain +85°C while the product is operating.”
Common Questions When Selecting an IEC 60068-2-2 Chamber
Is a +150°C chamber suitable for every dry heat test?
No.
Maximum temperature is only one parameter.
A suitable chamber must also provide:
- Temperature stability
- Uniformity
- Working space
- Airflow control
- Heat-load capability
Does the chamber temperature equal the specimen temperature?
Not always.
For heat-dissipating products, specimen temperature depends on:
- Internal heat generation
- Product design
- Airflow
- Installation arrangement
Do powered products require special chamber considerations?
Yes.
Powered products require evaluation of:
- Heat load
- Cable access
- Monitoring
- Airflow
How do I choose between GDW and GDJS?
A simple guideline:
Choose GDW when:
You mainly require:
- Dry heat testing
- Cold testing
- Temperature-only evaluation
Choose GDJS when:
You require:
- Dry heat
- Cold
- Humidity testing
- Multiple environmental programs
Can batteries use a standard dry heat chamber?
It depends on the battery type and test condition.
For potentially hazardous battery testing, additional safety evaluation may require an explosion-proof chamber configuration.
FAQ
What is IEC 60068-2-2?
IEC 60068-2-2 is an environmental test standard for dry heat testing.
It evaluates whether products can withstand controlled high-temperature conditions.
What products are tested according to IEC 60068-2-2?
Typical products include:
- Electronics
- Automotive components
- Industrial controllers
- Communication modules
- Battery electronics
What temperatures are commonly used?
Common dry heat conditions include:
- +55°C
- +70°C
- +85°C
- +100°C
- +125°C
- +150°C
The final condition depends on the product specification.
What are IEC 60068-2-2 Bb, Bd and Be tests?
They define dry heat test procedures according to:
- Heat dissipation characteristics
- Operating condition
- Energized state
How long does IEC 60068-2-2 testing take?
Common exposure durations include:
- 2 hours
- 16 hours
- 72 hours
- 96 hours
The actual duration depends on the product requirement.
Configure the Chamber Around the Test Requirement
A reliable IEC 60068-2-2 dry heat test starts with understanding the specimen.
Before selecting a chamber, define:
- What product is being tested?
- What temperature is required?
- Will the product operate?
- How much heat does it generate?
- What monitoring is required?
The chamber should reproduce the actual test condition, not simply achieve a high temperature.
For temperature-only applications, ITM-LAB GDW High & Low Temperature Test Chamber provides controlled dry heat and cold testing capability.
For laboratories requiring broader environmental reliability testing, ITM-LAB GDJS Programmable Temperature & Humidity Test Chamber provides a flexible platform.
For battery and higher-risk applications, ITM-DEP Explosion-Proof Chamber solutions can be evaluated according to the specific safety requirements.
Configure the chamber around the test—not the temperature range alone.
