Random vibration failures are not always obvious.
A cracked bracket or a loose screw is easy to spot. The more difficult failures are often hidden inside the product: a connector opens for a fraction of a second, a solder joint begins to fatigue, or an electronic module resets only while vibration is being applied.
Stop the shaker and the product may appear normal again.
That is one reason IEC 60068-2-64 random vibration testing is important in product reliability testing.
IEC 60068-2-64 defines Test Fh — Vibration, broadband random and guidance. The method is intended to evaluate whether a specimen can withstand specified broadband random vibration without unacceptable degradation of its structural integrity or functional performance.
It is relevant to products exposed to stochastic vibration during transportation or operation, including applications involving vehicles, aircraft, machinery and electronic equipment.
But a useful random vibration test involves much more than putting a product on a shaker.
The frequency range, PSD profile, overall Grms, exposure time, mounting condition, fixture, test direction and monitoring strategy all affect the result.
This guide looks at the test from a practical engineering perspective:
What can be tested? What does the vibration profile mean? What failures can appear? And how should the test system be selected?
What IEC 60068-2-64 Actually Simulates
Real-world vibration rarely occurs at one clean frequency.
Consider an ECU mounted in a vehicle.
The module may receive vibration generated by the road surface, tires, suspension, drivetrain and vehicle structure at the same time. An industrial controller installed close to a motor or compressor sees a different vibration environment, but the same principle applies: vibration energy exists across a range of frequencies.
Broadband random testing attempts to reproduce this type of dynamic environment under controlled laboratory conditions.
Instead of applying a single sinusoidal input, the vibration controller drives the shaker according to a defined random spectrum.
The objective is not simply to:
“Shake the product as hard as possible.”
The real objective is to reproduce a specified dynamic load and determine whether it causes:
- fatigue;
- loosening;
- cracking;
- component movement;
- intermittent electrical contact;
- signal interruption;
- performance degradation;
- structural or functional failure.
A good test therefore begins with the required vibration environment, not with a vibration machine model.
What Products Can Be Tested?
There is no single type of “IEC 60068-2-64 product.”
The specimen may be a connector, PCB assembly, automotive controller, avionics module or complete piece of electronic equipment.
The important question is whether broadband random vibration represents the expected service or transportation environment and whether the applicable product specification requires this test method.
Automotive Electronics
Automotive electronics are one of the most recognizable random vibration applications because a vehicle produces a complicated mechanical environment.
Possible DUTs include:
- ECU and body control modules;
- ADAS controllers;
- automotive camera modules;
- radar and sensing modules;
- pressure and position sensors;
- lighting electronics;
- BMS electronics;
- DC/DC converter assemblies;
- onboard charger electronics;
- inverter control assemblies;
- instrument modules;
- automotive connectors;
- terminal assemblies.
The failure mechanism depends on the product.
An ECU may develop fatigue around PCB mounting points.
A camera module may experience movement around an optical or connector interface.
A connector can remain physically engaged but temporarily lose electrical contact.
For this reason, the acceptance criteria should reflect what failure actually means for the DUT.
Aerospace and Aviation Electronics
Aircraft and aerospace equipment may be exposed to vibration from propulsion systems, rotating equipment, aerodynamic loading and structural transmission.
Possible specimens include:
- avionics modules;
- navigation electronics;
- communication modules;
- sensors;
- power supply assemblies;
- instrumentation;
- control electronics;
- other electronic subassemblies.
The industry name itself does not define the vibration severity.
An aerospace DUT still needs an applicable specification defining its frequency range, PSD profile, duration, axes and acceptance criteria.
Industrial Electronics
Industrial electronics may operate continuously near motors, pumps, compressors, machine tools and other vibration sources.
Typical products include:
- PLCs;
- servo drives;
- industrial inverters;
- power supplies;
- motor-control electronics;
- monitoring modules;
- industrial sensors;
- measurement instruments;
- automation controllers.
Weaknesses may develop gradually through connector movement, fastener loosening, PCB fatigue or resonance-related structural stress.
Telecom and Network Equipment
Communication hardware may also experience vibration during transportation, installation or operation.
Examples include:
- routers;
- switches;
- telecom power modules;
- communication control modules;
- optical communication equipment;
- network electronics;
- antenna-related electronics;
- base-station components.
For powered equipment, an intermittent communication dropout during the test may be more important than visible mechanical damage afterward.
Portable and Consumer Electronics
Depending on the qualification requirement, broadband random vibration testing may also be relevant to:
- smartphones;
- tablets;
- laptops;
- cameras;
- portable instruments;
- chargers;
- power adapters;
- display assemblies;
- smart electronic devices.
For finished electronics, it can help to think about the product as a collection of vibration-sensitive interfaces:
PCB → Solder Joint → Connector → Battery Mount → Camera Module → Display Mount → Fastener
The outer housing can survive while one of these internal interfaces fails.
Components and Subassemblies
A complete finished product is not required.
Engineers may also evaluate:
- PCB and PCBA assemblies;
- connectors;
- relays;
- switches;
- terminals;
- sensors;
- electronic modules;
- small electromechanical assemblies;
- mounting brackets.
Component-level testing can help identify mechanical weaknesses before the final product design is completed.
Frequency Range Alone Is Not a Random Vibration Test
This is one of the most common problems we see when discussing vibration equipment.
A customer may send:
“Random vibration: 10–500 Hz.”
That is useful information, but it does not yet define the test.
Two random vibration profiles can cover exactly the same frequency range and still impose very different loads on the DUT and shaker.
A useful test definition normally needs:
Frequency Range + PSD Profile + Overall Grms + Duration + Test Direction
For equipment sizing, we also need to understand:
DUT Mass + Fixture Mass + Mounting Arrangement + Table Configuration
Frequency Range
The frequency range defines the portion of the spectrum in which vibration is applied.
A product specification might require a range such as 10–500 Hz, 20–2,000 Hz or something completely different.
Those numbers are examples—not universal IEC 60068-2-64 conditions.
The applicable specification should define the required limits.
Copying the frequency range from an unrelated product does not reproduce the same vibration environment.
PSD: Where the Random Vibration Energy Goes
Random vibration is commonly described using Power Spectral Density (PSD).
Acceleration PSD is typically expressed in:
g²/Hz
The PSD curve shows how vibration energy is distributed across the frequency spectrum.
A profile may contain:
- rising sections;
- flat regions;
- falling sections;
- multiple breakpoints.
These details matter.
A flat PSD and a shaped PSD covering the same frequency range are not equivalent tests.
What Does Grms Tell You?
The PSD describes how vibration energy is distributed.
Overall Grms describes the overall RMS acceleration level associated with the defined random vibration spectrum.
In simplified terms, it is related to the area under the acceleration PSD curve across the specified frequency range.
That gives us an important distinction:
Frequency range tells us where the test occurs. PSD and Grms help describe the vibration severity.
Duration adds another factor.
A relatively high vibration level applied briefly should not automatically be treated as equivalent to a lower-level vibration applied for a much longer period.
This is why random vibration equipment should never be selected from frequency range alone.
IEC 60068-2-64 vs IEC 60068-2-6
IEC 60068 contains another commonly referenced vibration method:
IEC 60068-2-6 — Test Fc: Sinusoidal vibration.
Both methods may use an electrodynamic shaker system, but the input is fundamentally different.
| Test Item | IEC 60068-2-64 | IEC 60068-2-6 |
|---|---|---|
| Test method | Broadband random vibration | Sinusoidal vibration |
| IEC designation | Test Fh | Test Fc |
| Excitation | Random spectrum | Controlled sine |
| Main inputs | PSD, Grms, frequency, duration | Frequency, displacement / acceleration, sweep |
| Frequency content | Broad frequency content | Defined sinusoidal frequency |
| Typical purpose | Random environmental loading and accumulated stress | Sine response and endurance evaluation |
| Typical equipment | Electrodynamic vibration system | Electrodynamic vibration system |
Random vibration should not be described simply as a “stronger” version of sine vibration.
It is a different mechanical input.
A sine test can be especially useful where controlled excitation and resonance behavior matter.
A random test is useful when broadband dynamic loading must be reproduced.
The test method should follow the environment.
What Usually Fails First?
Random vibration does not always leave behind a visibly destroyed specimen.
Many failures begin at interfaces—places where structures, materials or electrical connections meet.
These are some of the areas worth watching.
Fasteners Begin to Move
Screws and mechanical joints experience repeated dynamic loading.
The first indication may be minor:
- reduced clamp security;
- movement between interfaces;
- changing alignment;
- abnormal rattling.
Continued exposure can eventually produce a clearly loose joint or cause secondary damage elsewhere.
Solder Joints Develop Fatigue
A PCB can flex dynamically during vibration.
That motion creates repeated local strain around component leads and solder joints.
A simplified failure path looks like this:
Random Vibration
↓
PCB Dynamic Response
↓
Repeated Local Strain
↓
Solder Fatigue
↓
Microcrack
↓
Electrical Interruption
The problem is that the microcrack may not be visible from outside the product.
Connectors Become Intermittent
Consider a connector that loses contact for only a few milliseconds while the shaker is running.
Once vibration stops, the contacts return to their normal position.
Post-test results may show:
Visual Inspection — PASS
Bench Function Test — PASS
But during vibration:
Electrical Continuity — FAIL
That is a completely different reliability result.
For products where temporary electrical interruption matters, live monitoring can be more useful than post-test inspection alone.
Brackets and Mounting Points Crack
Dynamic load can become concentrated around:
- mounting holes;
- bracket corners;
- thin sections;
- welded or joined interfaces;
- plastic bosses;
- housing attachment points.
If the DUT or mounting arrangement has a strong resonance within the test range, local response can become much higher than the input level.
Internal Components Shift or Detach
A component does not need to fall completely off to indicate a reliability problem.
Vibration may first cause:
- movement;
- looseness;
- partial separation;
- cracked supports;
- damaged cable retention;
- heat-sink movement;
- battery-holder damage.
These are often early stages of larger field failures.
A Product Can Pass Visually and Fail Functionally
This point deserves special attention because it changes how the test should be designed.
Consider an electronic controller.
Before Vibration
Housing — PASS
Power — PASS
Communication — PASS
Connector — PASS
During Vibration
Housing — No visible issue
Power — PASS
Communication — Intermittent dropout
Connector continuity — Interruption detected
After Vibration
Housing — PASS
Power — PASS
Communication on bench — PASS
If the test program included only before-and-after visual inspection, the failure could have been missed.
For products where temporary electrical or functional interruption matters, ask this question before testing:
What needs to be monitored while the shaker is running?
Depending on the DUT, monitoring may include:
- electrical continuity;
- contact resistance;
- supply voltage;
- sensor output;
- communication status;
- signal behavior;
- device operating state.
A Practical Random Vibration Test Workflow
The exact test program should follow the applicable specification, but a practical IEC 60068-2-64 test can be organized around the following workflow.
Define the Test Requirement
Before mounting the DUT, document:
- specimen configuration;
- mounting condition;
- frequency range;
- PSD profile;
- overall Grms;
- exposure time;
- required directions;
- operating or non-operating state;
- monitoring requirements;
- acceptance criteria.
This information is also needed to determine whether the vibration system can reproduce the requested profile.
Establish a Baseline
Inspect and measure the DUT before exposure.
Depending on the product, baseline information may include:
Visual Condition · Electrical Continuity · Resistance · Communication · Sensor Output · Functional Performance
A baseline gives engineers something meaningful to compare after testing.
Mount the DUT
The specimen is mounted to the shaker through the required interface or fixture.
The mounting arrangement should reproduce the intended mechanical boundary condition as closely as practical.
This is not simply a setup detail.
Mounting influences how vibration enters the DUT.
Install Control and Monitoring Accelerometers
A control accelerometer provides feedback to the vibration controller.
The controller uses this signal to regulate the shaker against the target random vibration profile.
Additional accelerometers may be installed on the fixture or DUT to observe dynamic response.
Powered electronics may also require separate electrical or functional monitoring channels.
Check the Response
Where required by the applicable test program, a low-level excitation or response investigation may be performed before full-level exposure.
This can help identify unexpected DUT or fixture resonances before the main test begins.
Apply the Random Vibration
The controller commands the shaker to reproduce the specified PSD profile.
During the test, engineers may record:
- control PSD;
- acceleration;
- DUT response;
- electrical continuity;
- communication;
- signal output;
- operating status.
Test the Required Directions
Some programs require testing along multiple orthogonal axes.
That may involve repositioning the DUT, changing fixture orientation or using a horizontal slip table.
The applicable specification determines the required directions.
Inspect Again—and Compare
After testing, repeat the relevant mechanical, electrical and functional checks.
The most useful question is not:
“Did the shaker complete the programmed profile?”
It is:
“What changed in the DUT?”
The Fixture Is Part of the Test
A poorly designed fixture can turn a good vibration profile into poor test data.
The fixture has two basic jobs:
- hold the specimen in the required orientation;
- transmit the required vibration input without introducing unacceptable dynamic behavior.
In practice, fixture mass, stiffness and geometry matter.
A flexible fixture can resonate inside the test frequency range.
An unnecessarily heavy fixture consumes shaker capability before the DUT is even considered.
Fixture design should therefore consider:
- DUT mounting interface;
- bolt pattern;
- fixture stiffness;
- fixture mass;
- center of gravity;
- test direction;
- target frequency range;
- sensor location.
This is also why shaker selection based only on DUT weight is unreliable.
The shaker has to move more than the DUT.
What Makes Up a Random Vibration Test System?
The shaker itself is only one part of the system.
A typical broadband random vibration setup includes:
Vibration Controller
↓
Power Amplifier
↓
Electrodynamic Shaker
↓
Vertical Table / Horizontal Slip Table
↓
Fixture
↓
DUT
with:
Control and Monitoring Accelerometers
connected to the measurement and control system.
Each part affects the usable test envelope.
ITM-LAB RS-V Electrodynamic Vibration Test System
The ITM-LAB RS-V Series Electrodynamic Vibration Test System is designed for controlled vibration testing of electronic components, automotive parts, portable devices, connectors and other specimens.
Current RS-V configurations include:
RS-V100 · RS-V150 · RS-V200 · RS-V300 · RS-V600 · RS-V1000
The series provides different excitation capabilities for different specimen and vibration requirements.
Available system elements include the electrodynamic shaker and power amplifier, with optional vibration controller configurations and horizontal sliding tables for applications requiring horizontal vibration.
For a broadband random vibration application, the complete system should be configured around the required random control capability and actual test profile.
That distinction is important.
A small PCB assembly and a large automotive module may both require random vibration testing, but they should not be approached as the same equipment-selection problem simply because the same IEC standard is referenced.
How to Size a Random Vibration System
This is where equipment selection should begin.
Not with:
“Which RS-V model should I use for a 20 kg product?”
Twenty kilograms is useful information.
It is not enough information.
For proper system sizing, several inputs need to be considered together.
DUT and Fixture Mass
Start by identifying the moving load.
This can include:
DUT + Fixture + Table / Interface
A large or heavy fixture can materially change the required shaker capability.
Complete PSD Profile
Whenever possible, provide the actual PSD spectrum.
A test specification, profile table or readable graph is far more useful than:
“Random vibration, 10–500 Hz.”
The spectrum determines how vibration demand changes with frequency.
Overall Grms
Overall Grms provides an additional measure of test severity.
It should be considered together with the PSD profile rather than used as a replacement for it.
Frequency Range
The complete system needs to operate over the required frequency range.
That includes more than the shaker.
The table, fixture, sensors and control arrangement can all influence usable performance.
Test Direction
Will the DUT be tested:
- vertically;
- horizontally;
- in multiple orthogonal directions?
A vertical-only setup and a system requiring a large horizontal slip table can have very different equipment requirements.
Force
The basic relationship:
F = m × a
helps explain why moving mass matters.
But random vibration sizing should not be reduced to multiplying DUT mass by Grms.
The required spectrum, total moving mass, system limits and appropriate engineering margin all need to be evaluated.
Displacement
Low-frequency portions of a vibration profile can create substantial displacement demand.
A shaker may have sufficient nominal force while still being unable to reproduce a profile because the required displacement exceeds its usable limit.
Velocity
Another profile may reach the system velocity limit before the force limit becomes the controlling factor.
For this reason, shaker selection should check the complete operating envelope:
FORCE + DISPLACEMENT + VELOCITY + ACCELERATION + FREQUENCY
A suitable model is one in which the actual test requirement fits inside the usable system envelope.
Vertical or Horizontal Testing?
For vertical vibration, the DUT may be mounted to the shaker armature or an appropriate expansion table.
For horizontal vibration, a horizontal slip table may be required.
This makes DUT geometry important.
A relatively light product can still need a large table because of its footprint.
Likewise, a large fixture can add significant moving mass.
A more useful selection sequence is:
DUT → Fixture → Direction → Table → Dynamic Requirement → Shaker
rather than:
DUT Weight → Shaker
When Random Vibration Is Not the Right Test
Not every mechanical reliability requirement belongs under IEC 60068-2-64.
When a Controlled Sine Test Is Required
Consider the applicable requirements of IEC 60068-2-6.
Sinusoidal vibration uses a different excitation method and may be more appropriate for defined sine sweeps, resonance-related investigation or sinusoidal endurance requirements.
When the Requirement Is Mechanical Shock
A test such as IEC 60068-2-27 may be more appropriate.
A short mechanical shock pulse and continuous broadband vibration represent very different mechanical events.
When You Need Drop or Rough-Handling Testing
For free-fall and handling-related requirements, a method such as IEC 60068-2-31 may be relevant.
Increasing shaker severity does not turn vibration into a drop test.
When You Are Testing Packaged Distribution
Start with the distribution environment.
Depending on the application, an ASTM, ISTA or other transportation testing procedure may provide a more appropriate vibration profile and overall test sequence.
IEC 60068-2-64 can be relevant to transportation-related vibration, but it should not automatically replace a packaging-specific distribution test.
The rule is simple:
Define the environment first. Select the test method second.
What About Temperature + Vibration?
Some products experience vibration while hot, cold or exposed to a controlled climatic environment.
Automotive and aerospace electronics are obvious examples.
Where required by the qualification specification, an electrodynamic vibration system may be integrated with a suitable environmental chamber.
A combined configuration can include:
RS-V Vibration System
Environmental Test Chamber
Suitable Table / Interface
Fixture and Sensors
Combined testing should not be added simply because it appears more severe.
Use simultaneous environmental stresses when the actual qualification requirement calls for them.
Before Requesting a Vibration System Quote
The fastest way to get a useful recommendation is to send the application requirement rather than just a desired machine model.
For a broadband random vibration application, provide:
- DUT name and application
- DUT dimensions
- DUT mass
- Number of DUTs tested simultaneously
- Mounting drawing or bolt pattern
- Frequency range
- Complete PSD profile
- Overall Grms
- Test duration per direction
- Required test directions
- Operating / non-operating condition and monitoring requirements
- Applicable test standard or product specification
If a fixture already exists, include its dimensions and mass.
If it does not, provide the DUT mounting information so the fixture can be considered as part of system sizing.
This information is much more useful than simply requesting:
“an IEC 60068-2-64 vibration machine.”
FAQ
What is IEC 60068-2-64?
IEC 60068-2-64 defines Test Fh, a broadband random vibration test method used to evaluate the ability of a specimen to withstand specified random dynamic loading without unacceptable structural or functional degradation.
What is the current IEC 60068-2-64 version?
The IEC consolidated publication is IEC 60068-2-64:2008+A1:2019.
When a project references the standard, always confirm whether the customer, laboratory or product specification requires this version or another contractually specified edition.
Which products can undergo IEC 60068-2-64 testing?
Depending on the applicable requirement, products may include automotive ECUs, sensors, PCBs, connectors, avionics, industrial controllers, telecom electronics, portable devices, power modules and electromechanical components.
The product category alone does not determine the test severity.
What is PSD in random vibration testing?
PSD means Power Spectral Density.
Acceleration PSD is commonly expressed in g²/Hz and describes how random vibration energy is distributed across frequency.
The vibration controller uses the defined spectrum as part of the target test profile.
Is Grms enough to define a random vibration test?
No.
Different PSD profiles can result in the same overall Grms.
A meaningful random vibration specification should also identify the PSD shape, frequency limits, duration and required test directions.
What is the difference between IEC 60068-2-64 and IEC 60068-2-6?
IEC 60068-2-64 covers broadband random vibration.
IEC 60068-2-6 covers sinusoidal vibration.
They reproduce different mechanical inputs and should not be treated as interchangeable test methods.
Should the DUT operate during vibration testing?
That depends on the applicable specification and product risk.
For some electronics, live operation and monitoring can identify temporary communication loss, contact interruption or functional resets that disappear once vibration stops.
Why is an accelerometer required?
The control accelerometer provides vibration feedback to the controller.
The controller uses this measurement to regulate the shaker output against the required profile.
Additional accelerometers can monitor fixture or DUT response.
Why does fixture design matter?
The fixture forms part of the vibration transmission path.
Its mass, stiffness and geometry influence the dynamic behavior of the setup.
A poor fixture can introduce resonance, consume shaker capability or prevent the intended input from being reproduced correctly at the specimen.
How do I select the correct RS-V vibration system?
Start with:
DUT + Fixture Mass
Frequency Range
PSD Profile
Overall Grms
Duration
Vertical / Horizontal Requirement
Then check:
Force + Displacement + Velocity + Acceleration + Frequency
Only after those requirements are defined should the shaker, amplifier, table, controller, sensors and fixture be configured.
The Shaker Is Only One Part of the Test
PSD and Grms receive a lot of attention in random vibration testing, but they are only part of the engineering problem.
The DUT has mass.
The fixture has stiffness and mass.
The table becomes part of the moving system.
The shaker has force, velocity, displacement and frequency limits.
The vibration controller has to reproduce the target spectrum.
And the product may need to be monitored while all of this is happening.
That is why an IEC 60068-2-64 random vibration test system should be approached as a complete system rather than a standalone vibration machine.
For broadband random vibration applications, the ITM-LAB RS-V Series Electrodynamic Vibration Test System can be evaluated and configured around the required PSD profile, overall Grms, frequency range, DUT and fixture mass, test direction, table configuration and monitoring requirements.
When requesting a configuration, send us the DUT dimensions and mass, PSD profile, Grms, frequency range, test duration and required test axes.
Those inputs tell us far more about the right vibration system than a model number ever could.
Define the vibration environment first. Build the test system around it.
