Cold conditions can affect far more than whether a product simply turns on.
At low temperatures, electronic components may respond differently, batteries deliver less power, displays and mechanical parts may become slower, seals and plastics may stiffen, and differences in thermal contraction can affect connections or assemblies.
IEC 60068-2-1:2025 — Environmental testing — Part 2-1: Tests — Test A: Cold provides a standardized method for evaluating components, equipment and other articles under defined low-temperature conditions.
For a test engineer or equipment buyer, however, knowing the standard number is only the beginning.
A practical test setup must answer several additional questions:
- Is the specimen heat-dissipating?
- Will it operate during the test?
- What cold temperature and exposure time are required?
- When does the actual exposure period begin?
- How much heat will the specimen add to the chamber?
- Does chamber airflow affect specimen temperature?
- How much working space is really required?
This guide explains the IEC 60068-2-1 cold test procedure and turns these requirements into a practical chamber-selection solution.
Standard update: IEC 60068-2-1:2025 is Edition 7.0 and replaces IEC 60068-2-1:2007.
What Is IEC 60068-2-1?
IEC 60068-2-1 defines Test A: Cold.
Its purpose is to determine the ability of components, equipment or other articles to be used, transported or stored at low temperature.
The test can apply to:
- Heat-dissipating specimens
- Non-heat-dissipating specimens
- Energized specimens
- Non-energized specimens
- Packed specimens for transportation or storage conditions
- Unpacked specimens representing use conditions
One distinction is important from the beginning.
IEC 60068-2-1 evaluates the effect of cold exposure. It is not intended primarily to evaluate damage caused by the temperature transition itself.
For that reason:
IEC 60068-2-1 → Cold Exposure
IEC 60068-2-14 → Change of Temperature
If the engineering question is:
Can this product operate or survive at -40°C?
IEC 60068-2-1 may be the relevant test method.
If the question is:
Can this product survive repeated transitions between low and high temperatures?
A temperature-change method such as IEC 60068-2-14 may be more appropriate.
Which Products Use IEC 60068-2-1 Cold Testing?
IEC 60068-2-1 is a test-method standard rather than a product certification standard for one specific industry.
Whether a particular product must be tested according to IEC 60068-2-1 depends on the relevant product specification, qualification program, customer requirement or internal reliability plan.
Typical applications include:
| Industry | Typical Products | Typical Cold-Test Concerns |
|---|---|---|
| Consumer Electronics | Smartphones, tablets, cameras, wearables, chargers | Startup, display, controls, electrical connection, material behavior |
| Automotive Electronics | ECUs, sensors, lighting modules, controllers, infotainment | Cold start, electronic function, connectors, component reliability |
| PCB & Electronic Components | PCBAs, connectors, relays, modules, sensors | Electrical stability, connections, solder joints |
| Industrial Electronics | PLCs, HMIs, power supplies, control modules | Startup and continuous operation at low temperature |
| Telecommunications | Communication modules, outdoor electronics, routers | Cold startup and communication reliability |
| Battery & Energy Systems | BMS, battery modules, storage electronics | Low-temperature operation and electrical performance |
| High-Reliability Electronics | Control assemblies, sensors, electronic modules | Function under severe cold conditions |
The important point is that the industry alone does not define the test severity.
Two electronic products may both reference IEC 60068-2-1 while requiring completely different temperatures, exposure times and operating conditions.
First Decision: Is the Specimen Heat-Dissipating?
This is one of the most important decisions in IEC 60068-2-1 testing.
A powered specimen that generates sufficient internal heat does not behave like an unpowered connector or passive component.
Under IEC 60068-2-1:2025, a specimen is considered heat-dissipating when the relevant measured temperature rise under defined free-air conditions exceeds the specified criterion.
In practical chamber selection, this distinction matters because a heat-dissipating product introduces two additional variables:
Specimen Heat
and
Airflow
Consider an ECU operating inside a -40°C chamber.
The chamber air may be at -40°C while some areas of the powered ECU remain considerably warmer.
Increasing chamber air velocity may cool the ECU more aggressively, changing its temperature compared with a low-air-velocity installation.
That means:
Chamber air temperature alone does not always describe the thermal condition experienced by a powered specimen.
IEC 60068-2-1 Test Ab, Ad and Ae
The standard provides three primary cold-test procedures.
| Method | Specimen | Power Condition | Main Chamber Consideration |
| Test Ab | Non-heat-dissipating | Non-operating or operated as specified | Temperature stability and specimen stabilization |
| Test Ad | Heat-dissipating | Energized after initial stabilization | Low air velocity, heat load, specimen temperature |
| Test Ae | Heat-dissipating | Energized throughout the test | Continuous heat load, airflow and refrigeration capacity |
Test Ab — Non-Heat-Dissipating Specimens
Test Ab is used for specimens that do not produce significant heat.
Typical examples can include:
- Connectors
- Passive components
- Relays
- Unpowered PCB assemblies
- Material specimens
- Sensors in a non-operating condition
The specimen is cooled gradually to the required low conditioning temperature and allowed to stabilize before completing the specified exposure.
Test Ad — Heat-Dissipating Specimens Energized After Stabilization
Test Ad applies to heat-dissipating specimens that are energized after the initial temperature stabilization period.
Typical examples may include:
- ECU
- Power electronics
- Industrial controller
- Communication equipment
- Powered electronic assemblies
For these specimens, the chamber must handle both the external cold condition and the heat generated by the product.
Test Ae — Heat-Dissipating Specimens Energized Throughout
Test Ae applies when the specimen must remain energized throughout the test, including the conditioning period.
Possible examples include:
- BMS electronics
- Power supplies
- Continuous-operation controllers
- Communication electronics
- Powered control systems
For Test Ae, knowing only that a chamber can reach -40°C when empty is not enough.
A more useful question is:
Can the chamber maintain the specified test condition while the specimen is continuously generating heat?
IEC 60068-2-1 Cold Test Procedure
The exact sequence depends on whether Test Ab, Ad or Ae is selected, but the practical workflow can be summarized as follows.
1. Define the Test Severity
Before programming the chamber, define:
- Low conditioning temperature
- Exposure time
- Specimen operating condition
- Functional checks
- Pass/fail criteria
Whenever available, these values should come from the relevant product specification.
2. Classify the Specimen
Determine whether the specimen is:
Non-Heat-Dissipating
or
Heat-Dissipating
Then define whether it is:
OFF
Powered after stabilization
or
Powered throughout
This establishes the appropriate Ab, Ad or Ae procedure.
3. Install the Specimen in the Working Space
Place the specimen in the chamber so that the test setup does not unnecessarily obstruct air circulation.
Keep appropriate clearance from:
- Chamber walls
- Air outlets
- Air returns
- Other specimens
For energized tests, prepare external connections for power, signals and monitoring.
4. Reduce the Chamber Temperature
The test begins from the required initial atmospheric condition and the chamber temperature is reduced toward the specified cold condition.
IEC 60068-2-1 is a gradual cold-conditioning test.
The objective is not to create unintended thermal shock while cooling the specimen.
5. Wait for the Specimen — Not Just the Chamber
This is where many practical tests can go wrong.
Suppose the controller reaches:
-40.0°C
The chamber is at setpoint.
But is the specimen?
A small connector may respond quickly. A heavy aluminum assembly, large control unit or battery module can take much longer.
For this reason, the engineer may need to monitor representative points on or inside the specimen to confirm temperature stabilization.
Chamber setpoint reached ≠ specimen stabilized.
6. Apply the Required Operating Condition
Depending on the selected procedure:
Test Ab
The specimen remains in the specified operating or non-operating condition.
Test Ad
The heat-dissipating specimen is energized after initial stabilization.
Test Ae
The specimen remains energized throughout the required period.
For powered specimens, a further stabilization period may be necessary after energizing.
7. Start the Required Exposure
Once the required test condition and specimen stabilization criteria have been satisfied, the specified exposure period is completed.
During exposure, the test plan may include:
- Voltage/current measurement
- Functional checks
- Communication monitoring
- Data recording
- Mechanical operation
- Alarm monitoring
8. Recovery and Final Evaluation
After conditioning, return the specimen according to the specified recovery procedure and perform the required final inspection.
Depending on the product, evaluation may include:
- Startup
- Electrical performance
- Communication
- Visible cracking
- Deformation
- Mechanical operation
- Insulation
- Functional performance
A product that appears normal inside the chamber can still develop a failure during or after recovery.
What Temperatures Are Used for IEC 60068-2-1?
IEC 60068-2-1 does not require every product to be tested at -40°C.
The test severity should first be specified by the relevant product specification.
IEC 60068-2-1:2025 lists preferred low conditioning temperatures including:
| Preferred Temperature |
| +5°C |
| -5°C |
| -10°C |
| -20°C |
| -25°C |
| -33°C |
| -40°C |
| -50°C |
| -55°C |
| -65°C |
If the relevant specification does not provide a severity, appropriate conditions can be selected from the standardized values or derived from the known service environment or relevant field data.
For chamber buyers, this creates a simple selection principle:
Required Test Temperature → Chamber Temperature Range
Examples:
A laboratory testing mainly to -20°C may not need the same refrigeration system as a laboratory routinely qualifying products at -55°C.
Likewise, a laboratory with a current -40°C test requirement but expected future -55°C programs may find a -70°C chamber more practical over the equipment's service life.
The selection should be based on the test plan, not simply on choosing the lowest available temperature.
How Long Does the Cold Test Last?
IEC 60068-2-1:2025 provides preferred exposure durations including:
2 h · 16 h · 72 h · 96 h
Again, these are not universal mandatory durations for every product.
The applicable product requirement determines the correct test severity.
One detail is easy to miss:
Stabilization Time Is Not the Same as Exposure Time
Consider this sequence:
Cooling
↓
Specimen Stabilization
↓
Specified Exposure
↓
Recovery
If a large product requires several hours to reach thermal stability, that period should not automatically be confused with the required low-temperature exposure.
This is especially important for:
- Large metal assemblies
- Large electronic enclosures
- Dense products
- Batch testing
- Powered equipment
IEC 60068-2-1 Test Chamber Requirements
A cold chamber should not be selected from minimum temperature alone.
For IEC 60068-2-1 testing, six engineering questions are more useful.
1. Can the Chamber Reach the Required Temperature?
Typical environmental chamber configurations may include:
-20°C to +150°C
-40°C to +150°C
-70°C to +150°C
The range should cover both the current test requirement and reasonable future programs.
2. Can It Maintain the Required Condition Across the Working Space?
Temperature stability and spatial temperature performance affect test repeatability.
A chamber reaching -40°C at its control sensor does not necessarily mean every point around a heavily loaded test specimen is experiencing exactly the same environment.
This is why specifications such as:
- Temperature fluctuation
- Temperature deviation
- Temperature uniformity
should be considered separately from the nominal temperature range.
3. Is the Chamber Large Enough After the Specimen Is Installed?
A 408 L chamber does not mean 408 L of specimen can simply be packed inside.
Usable test space depends on:
Specimen Size + Quantity + Clearance + Airflow + Fixtures + Cables
Overloading a chamber can restrict circulation and increase temperature gradients.
For multiple specimens, arranging the load correctly can be just as important as nominal chamber volume.
4. Is Air Velocity Important for the Specimen?
For non-heat-dissipating specimens, forced circulation helps bring the specimen toward chamber temperature efficiently.
For heat-dissipating specimens, the situation is different.
Higher air velocity can produce additional convective cooling.
This can change:
- Surface temperature
- Internal component temperature
- Hot-spot behavior
- Thermal equilibrium
IEC 60068-2-1:2025 therefore gives additional attention to determining whether the test chamber provides high or low air velocity for heat-dissipating Test Ad and Test Ae procedures.
For this type of application, airflow is not simply a chamber specification.
It is part of the test condition.
5. How Much Heat Does the Specimen Generate?
Suppose a laboratory tests:
5 controllers × 100 W
The chamber sees approximately:
500 W of specimen heat load
A chamber that can reach -40°C when empty may not provide the same performance under that load.
Powered testing therefore requires the manufacturer to know:
- Heat load per specimen
- Number of specimens
- Required low temperature
- Test duration
- Operating condition
This information should ideally be provided before the chamber is selected.
6. How Will the Specimen Be Monitored?
Powered cold testing may require:
- Power cables
- Signal cables
- Thermocouples
- Voltage/current monitoring
- Communication cables
- External measuring equipment
Cable ports and appropriate feedthrough arrangements become particularly important when testing ECUs, BMS units, PLCs and other powered electronics.
ITM-LAB IEC 60068-2-1 Cold Test Solution
Instead of starting with a chamber model, an IEC 60068-2-1 configuration should start with the specimen.
The selection path is:
SPECIMEN
↓
TEST METHOD
↓
TEMPERATURE & TIME
↓
OPERATING STATE
↓
HEAT LOAD & SIZE
↓
CHAMBER CONFIGURATION
This prevents a common purchasing problem: selecting a chamber that has the correct temperature range on paper but is poorly matched to the actual test.
Solution 1 — GDW High & Low Temperature Test Chamber
Best suited for:
Temperature-only environmental testing
Typical specimens:
- PCB and electronic components
- Connectors
- Sensors
- Automotive electronics
- Industrial components
- Plastics and materials
A GDW high and low temperature chamber is appropriate when the laboratory primarily requires controlled:
Cold Testing
and
Dry Heat Testing
without a humidity test requirement.
The final configuration should be selected according to the required temperature, specimen dimensions, loading and heat dissipation.
Solution 2 — GDJS Programmable Temperature & Humidity Test Chamber
Best suited for:
Laboratories requiring several IEC 60068 environmental tests on one platform
ITM-LAB GDJS configurations include temperature ranges down to:
-40°C / -70°C to +150°C
with:
20–98% RH
and chamber capacities including:
100 / 150 / 225 / 408 / 800 / 1000 L
This makes GDJS useful when the laboratory needs IEC 60068-2-1 cold testing but also expects to perform environmental methods involving:
- Dry heat
- Damp heat
- Temperature and humidity exposure
For many electronics, automotive and industrial laboratories, this can be more flexible than purchasing a chamber dedicated only to cold exposure.
Solution 3 — Explosion-Proof High & Low Temperature Chamber
Best suited for:
Potentially hazardous battery specimens
Lithium-ion batteries require additional safety assessment.
If cells or modules are energized, charged, discharged or otherwise capable of entering a hazardous condition during testing, a conventional temperature chamber should not automatically be assumed suitable.
ITM-LAB explosion-proof high and low temperature chambers can be configured with safety systems such as:
- Pressure relief
- Smoke detection
- Fire suppression
- Reinforced chamber construction
- Explosion-proof door protection
- Remote monitoring
The required safety configuration depends on battery type, capacity, test condition and risk assessment.
Which Chamber Should You Choose?
| Test Requirement | Specimen Example | Main Concern | Suggested ITM-LAB Solution |
| Cold test, non-powered | Connector / PCB / Material | Temperature & stability | GDW |
| Cold test, powered electronics | ECU / Controller / PLC | Heat load & airflow | GDW / GDJS configured for load |
| Cold + humidity programs | Electronics / Automotive modules | Multiple environmental tests | GDJS |
| Severe low temperature | High-reliability electronics | -55°C / -65°C testing | -70°C GDW / GDJS configuration |
| Battery cold testing | Cell / Module / BMS | Temperature + safety | Explosion-Proof Chamber |
| Rapid temperature change | Electronic assemblies | Thermal transition stress | KTB / IEC 60068-2-14 solution |
This is the key difference between choosing a chamber by catalogue and configuring one around an actual test.
A Practical Example: -40°C Powered ECU Test
Consider an automotive electronics laboratory preparing a cold test for several powered ECUs.
The initial requirement is:
Target temperature: -40°C
Specimen: ECU
Quantity: 4
Operating condition: Powered during cold exposure
Selecting a chamber by saying:
“We need a -40°C chamber.”
is incomplete.
The equipment supplier should also know:
How much heat does each ECU generate?
If each ECU dissipates approximately 80 W:
4 × 80 W = 320 W total specimen heat load
The chamber must therefore maintain the required low-temperature condition while compensating for this heat.
The laboratory must also consider:
- ECU dimensions
- Spacing between four samples
- Airflow around the samples
- Cable access
- Power connections
- Specimen temperature measurement
- Required exposure duration
Only after these parameters are known can the chamber configuration be matched properly to the test.
This is why chamber selection should begin with the specimen, not the catalogue temperature range.
IEC 60068-2-1 vs IEC 60068-2-14
These standards solve different engineering problems.
| IEC 60068-2-1 | IEC 60068-2-14 | |
| Test | Cold | Change of Temperature |
| Main Question | Can the product withstand low temperature? | Can it withstand temperature transitions? |
| Condition | Defined cold exposure | Defined temperature changes/cycles |
| Primary Concern | Low-temperature use, transport or storage | Thermal stress |
| Typical Equipment | High/Low Temperature Chamber | Thermal Cycle / Rapid Change Chamber |
| ITM-LAB Solution | GDW / GDJS | KTB / Thermal Shock System |
A faster chamber is therefore not automatically a better IEC 60068-2-1 chamber.
The equipment should reproduce the test condition required by the standard and the relevant product specification.
Common IEC 60068-2-1 Test Setup Mistakes
Starting the timer when the controller reaches -40°C
The specimen may not yet be thermally stable.
Check specimen stabilization where required before treating chamber setpoint as the start of exposure.
Ignoring heat generated by powered products
An energized controller may change the chamber's thermal load significantly.
Provide heat-load data before selecting the refrigeration system.
Filling the chamber with too many specimens
More samples improve throughput only if adequate temperature conditions can still be maintained.
Leave sufficient space for controlled airflow.
Treating chamber air temperature as specimen temperature
This is particularly risky with large or powered products.
Use appropriate specimen measuring points when the test requires them.
Choosing a chamber only by “-70°C”
Minimum temperature is only one specification.
Working space, airflow, stability, heat-load capacity and monitoring may be equally important.
What Information Should You Send When Requesting an IEC 60068-2-1 Chamber?
A useful RFQ should include:
| Information | Example |
| Specimen | Automotive ECU |
| Size | 250 × 180 × 80 mm |
| Quantity | 4 units |
| Required temperature | -40°C |
| Exposure time | 16 h |
| Operating state | Powered |
| Heat dissipation | 80 W/unit |
| Total heat load | 320 W |
| Humidity tests required? | Yes / No |
| Cable connections | Power + CAN communication |
| Safety requirements | Standard / Battery protection |
Providing these details allows the chamber manufacturer to evaluate the test rather than simply quote a machine with the requested minimum temperature.
FAQ
What is the latest edition of IEC 60068-2-1?
The current edition is IEC 60068-2-1:2025, Edition 7.0, which replaced the 2007 edition.
Does IEC 60068-2-1 require -40°C?
No.
IEC 60068-2-1 provides preferred low conditioning temperatures, while the relevant product specification should determine the actual severity.
What are IEC 60068-2-1 Test Ab, Ad and Ae?
Test Ab is for non-heat-dissipating specimens.
Test Ad is for heat-dissipating specimens energized after initial temperature stabilization.
Test Ae is for heat-dissipating specimens required to be energized throughout the test.
What are the preferred exposure times?
IEC 60068-2-1:2025 provides preferred durations including:
2 h, 16 h, 72 h and 96 h.
The actual test duration should follow the relevant specification.
Can an ordinary -40°C chamber test powered electronics at -40°C?
Possibly, but the temperature rating alone is not enough to determine suitability.
The chamber must also be evaluated against:
- Total specimen heat load
- Chamber working volume
- Airflow
- Temperature performance
- Required operating condition
Is IEC 60068-2-1 used for automotive electronics?
It can be used as a cold environmental test method when referenced by the applicable component specification, customer requirement or qualification plan.
Typical specimens include ECUs, sensors, electronic modules, controllers and lighting electronics.
Can batteries be tested in a standard environmental chamber?
The answer depends on the battery, operating condition and risk assessment.
Potentially hazardous energized lithium-ion cells or modules may require an explosion-proof temperature chamber with additional safety systems.
Building the Right IEC 60068-2-1 Test Setup
A compliant cold-test program does not begin with:
“Which -40°C chamber should I buy?”
It begins with:
What are we testing?
At what temperature?
For how long?
Will it be powered?
How much heat will it generate?
How much working space will it require?
Once these questions are answered, the appropriate chamber configuration becomes much clearer.
For temperature-only applications, GDW can provide the required high and low temperature environment.
For laboratories that also need humidity testing, GDJS provides a broader programmable environmental testing platform.
For potentially hazardous battery specimens, an ITM-LAB explosion-proof chamber can provide the additional safety configuration required for the application.
Configure the chamber around the specimen and test requirement—not temperature range alone.
Explore ITM-LAB Environmental Test Chambers for IEC 60068-2-1 cold testing, or provide your specimen size, required temperature, operating condition and heat load for chamber configuration.
