Pulse shape, duration, velocity change, frequency content, directions, event count, and measurement location change the load.
Industrial sensor durability guide
How Shock Testing Validates Industrial Sensor Durability
A credible shock test applies a controlled transient through the intended mounting path, measures what reaches the sensor, and verifies that its structure and required function remain acceptable.
Direct answer
Shock testing can reveal cracks, loosened parts, intermittent electrical faults, calibration shift, reset events, connector movement, seal damage, and loss of sensing function. The result applies only to the tested model, mounting, pulse or spectrum, axes, cable state, operating condition, and acceptance criteria.
Background photo: Sergey Sergeev / Pexels.
Mounting stiffness, fastener torque, bracket geometry, cable support, and control point determine what reaches the sensor.
A post-test pass can miss a short output glitch, analog spike, reset, or communication interruption that recovered afterward.
Four checks separate a useful test from a marketing badge.
A buyer does not need to design the laboratory setup. You do need enough information to decide whether the evidence represents your actual sensor installation and machine function.
Request the full pulse or SRS, not only peak acceleration. Include axes, directions, event count, and tolerance.
Match the input to the real threat.Fixture, bracket, fasteners, torque, cable, connector, and external mass shape the delivered load.
Compare it with the production installation.Define output continuity, analog value, diagnostics, reset, communications, configuration, calibration, and sensing margin.
Test during impact when operation matters.Identify the specimen, instruments, actual time histories or spectra, acceptance criteria, deviations, and product revision.
Make requalification triggers explicit.Shock testing validates a defined sensor system, not universal ruggedness.
What a well-designed test can establish
The identified sensor and installation survived the stated transient without unacceptable structural damage or functional degradation, under the mounting, operating, and acceptance conditions recorded in the test.
Mechanical shock is a brief, high-intensity change in motion. The sensor is fixed to a shock machine or representative fixture, subjected to a defined pulse or shock response spectrum, and inspected or monitored against stated limits.
The purpose is not to prove that the product is indestructible. IEC 60068-2-27 describes a controlled method for revealing mechanical weakness, performance degradation, accumulated damage, or structural-integrity problems under defined shocks. It also emphasizes that the severity and pulse shape should, where possible, represent the actual transport or operating environment or the design objective.
Durable-sensor rule: Change the bracket, fastener torque, cable restraint, connector, housing revision, sensing geometry, orientation, or pulse spectrum and the engineering risk can change. Relevance must be reviewed before reusing an old report.
A static bench test may miss the short inertial forces and local bending moments created by shock. A sensor can look normal after impact while a solder joint briefly opens, a connector contact moves, a lens shifts, a pressure zero changes, or a seal develops a latent weakness.
Primary source: IEC 60068-2-27:2008, Environmental testing - Test Ea and guidance: Shock.
Choose the right mechanical test
Shock, vibration, drop, and package testing answer different questions.
They may all involve acceleration, but specimen condition, input, duration, and failure mechanism are not interchangeable.
Classical mechanical shock
A mounted specimen receives a controlled time-domain pulse with stated shape, peak, duration, direction, and event count.
Best for an installed or service shock represented by the chosen pulse.Shock response spectrum
The test is controlled or assessed against a response envelope across frequency with stated damping, band, location, and tolerance.
Best when a simple pulse does not describe the interface environment.Sine or random vibration
Oscillatory input is applied over frequency and time to identify resonance, fatigue, or workmanship sensitivity.
Useful for endurance, but not proof of a specified impact transient.Drop or rough handling
The product falls, topples, bounces, or receives handling knocks without the same installed mounting path.
Useful for service handling, not a substitute for mounted shock.Official scope distinction: IEC 60068-2-31 states that rough-handling procedures do not simulate shock applied to installed equipment and do not represent loosely constrained cargo transport. Use the method that matches the threat.
Reference: IEC 60068-2-31:2008, Rough handling shocks.
Why peak g is incomplete
A shock requirement needs a shape, time, direction, and interface.
A short sharp pulse and a longer pulse can share the same peak acceleration yet excite different sensor and fixture modes. Review the complete event, not a single catalog number.
Delta v = 2 x a_peak x T / piIdeal half-sine pulse only. This explains why duration changes velocity change; it does not replace a measured time history, SRS, or structural-response assessment.Units matter: State acceleration units, duration definition, polarity, control location, tolerance, filtering, sample rate, and bandwidth. Never infer them from a bare “50 g shock” statement.
AccelerationTime
Pulse shapeChanges energy and frequency content.
AxesExpose direction-sensitive weak paths.
Control pointDefines where the input is measured.
Minimum profile definition
Seven fields give a shock specification engineering meaning.
| Profile field | Why it changes sensor response | What the report should show | Common mistake |
|---|---|---|---|
| Pulse shape or SRS | Different waveforms distribute transient energy differently. | State the shape or spectral envelope, tolerance, and selection basis. | Comparing only peak g. |
| Peak acceleration | Sets one part of inertial load but not time or frequency content. | Record units, polarity, location, tolerance, and measured actual value. | Ignoring control location. |
| Duration and bandwidth | Determines velocity change and which structural modes can be excited. | Define duration, filtering, sample rate, analysis band, and instrument capability. | Using unsuitable acquisition. |
| Axes and directions | Cable, connector, PCB, lens, seal, and mounting boss may be weaker in one direction. | Map test axes to the production installation and count events per direction. | Testing only the convenient axis. |
| Fixture and torque | Stiffness, fastener preload, bracket geometry, and moment arms change the load path. | Provide fixture photos/drawing, hardware, material, interface, and torque. | Using an unrealistically rigid mount. |
| Control and response points | The table input may differ from the acceleration delivered at the sensor interface. | Show accelerometer position, orientation, calibration, time histories, and response data. | Measuring too far from the specimen. |
| Operating state and acceptance | Transient functional faults may disappear before post-test inspection. | Define power, load, target, monitoring, limits, inspection, and retest rules. | Calling a cosmetic survivor a pass. |
Two control approaches
Use a classical pulse or SRS only when it matches the application.
SRS is not automatically “better” or “more severe.” It is a different way to describe a transient environment.
Classical pulse
Controls acceleration against time at a defined fixture or specimen interface. It is a strong fit when a half-sine or other specified pulse reasonably represents the actual event.
- Report shape, peak, duration, direction, and event count.
- Provide measured acceleration time histories.
- Check response at the actual sensor interface where needed.
Shock response spectrum
An SRS summarizes the maximum response of ideal single-degree-of-freedom oscillators across frequency for a stated damping assumption. Different time histories can meet a similar envelope.
- State frequency band, damping or Q, tolerance, and location.
- Include measured time histories and SRS conformance plots.
- Avoid importing aerospace profiles without an application basis.
NASA describes shock testing as applying a pulse or SRS at the mechanical interface and recommends careful accelerometer placement near structural interfaces and predicted high-response locations: NASA SSRI Shock Testing Knowledge Base.
Follow the mechanical path
Shock travels through the mounting system before it reaches the sensing function.
The same sensor can see a very different event on a stiff machine face, a flexible bracket, a long threaded stand-off, or a cable-loaded connector.
1Machine event
Press impact, valve closure, collision, mobile-equipment motion, or handling event creates the transient.
2Bracket and fasteners
Stiffness, torque, contact area, moment arm, and resonance shape the interface input.
3Housing and connector
Threads, bosses, cable exits, connector inserts, and seams carry local stress.
4PCB and sensing element
Mass and alignment create loads on solder, components, coils, lenses, magnets, or diaphragms.
5Output and control system
The machine sees false output, analog error, reset, lost communication, shifted aim, or no visible fault.
What can fail first
The weakest part may not be the housing.
Acceptance checks should follow the likely failure path for the sensor technology and installation.
Housing or mounting crack
Stress concentrates at a thread, boss, flange, weld line, sharp section, or flexible bracket.
Verify with inspection, dimensions, torque, and interface response.Intermittent contact or solder fault
A joint or contact opens during the pulse and reconnects before the operator checks it.
Verify with high-speed electrical or communication monitoring.Calibration or threshold shift
A lens, coil, magnet, diaphragm, reference, PCB, or sensing element moves relative to its datum.
Verify with controlled pre/post multi-point measurements.Latent cable-entry or potting damage
Local strain creates a future water path that may appear only after thermal or moisture exposure.
Verify with targeted leak, ingress, thermal, or section analysis.Bracket changes the target gap
The sensor survives, but the mounted geometry moves enough to create a false transition.
Verify with the real target, approach direction, and operating margin.Reset or configuration loss
Power interruption or connection movement creates a reboot, diagnostic event, or lost parameter.
Verify reset counters, error logs, configuration, and cyclic data.
Test the function that matters
Power the sensor when it must operate through impact.
An unpowered shock test can answer mechanical-survival questions. It cannot prove that an operating sensor avoided a brief output glitch, analog spike, reboot, or communication interruption.
Digital output
Log output state and pulse timing against the shock input, using a time resolution suited to the fault of concern.
Analog value
Monitor transient error, offset, noise, clipping, and pre/post calibration at relevant reference points.
Communication
Capture link loss, CRC or protocol errors, missed cyclic data, recovery time, and reset counts.
Sensing margin
Use the actual target or medium and record threshold, excess gain, distance margin, or alignment as applicable.
Configuration
Verify firmware, teach state, parameters, diagnostics, and nonvolatile settings after the event.
Do not let the data system hide the fault: acquisition bandwidth, filtering, sample rate, trigger logic, and controller scan time must be able to capture the transient being investigated.
Fixture and instrumentation
A poorly controlled setup can under-test or over-test the sensor.
The table command is not automatically the acceleration at the sensor. The fixture, bracket, cable, fasteners, accelerometer, and acquisition chain all affect test validity.
For installation planning, review why sensor mounting stability affects accuracy.
Use production hardware, torque, bracket stiffness, orientation, connector, cable support, and relevant external mass.
Check that fixture dynamics do not create a false amplification, excessive cross-axis response, or a control artifact.
Document locations, orientations, mounting method, calibration, bandwidth, range, and time histories.
Define over-test protection, response limits, notching or abort logic, and how deviations or interrupted events are handled.
Manufacturer engineering example: Analog Devices explains how mounting technique and cable anchoring affect sensor system response.
Qualification workflow
Durability evidence needs configuration and change control.
A test report stays relevant only while production continues to build the sensor configuration that was qualified.
1
Define the real event and failure consequence
Use field measurements, machine data, sector requirements, or a documented design objective.
2
Freeze the tested configuration
Identify model, revision, cable/connector, firmware, bracket, fasteners, torque, target, and accessories.
3
Run pre-test characterization
Record sensing, calibration, communication, visual, mechanical, and sealing baselines as relevant.
4
Apply and monitor the shock
Control the input, capture response data, monitor required functions, and preserve anomalies.
5
Inspect, measure, and diagnose
Compare pre/post results, investigate root cause, document deviations, and define requalification triggers.
Do not hide the anomaly
A failed test is useful only when the evidence is preserved.
Repeating a shock until the sensor passes can destroy the most valuable information. Keep the original time history, functional trace, photos, specimen identity, fixture condition, and deviations before changing the setup.
1. Confirm the test was valid
Check input, accelerometer behavior, fixture response, trigger, cable support, mounting, and acquisition limits.
2. Match event timing to the symptom
Align output, analog, power, diagnostic, communication, and acceleration records.
3. Inspect the complete load path
Review bracket, fasteners, housing, connector, cable, PCB, sensing element, seals, and target geometry.
4. Reproduce the cause, not only the failure
Change one justified variable, repeat at controlled conditions, and document the corrective action.
Combined-environment warning: shock can create a latent seal or cable weakness that appears only after temperature cycling, moisture, flexing, or chemical exposure. Environmental ratings should be reviewed as an interacting system.
Buyer report checklist
What credible shock-test evidence should contain
A reviewer should be able to reconstruct what was tested, how the load was delivered, which function was monitored, and why the result applies to the ordered sensor.
Model, revision, serial or lot, firmware, parameter set, cable/connector, accessories, and initial condition.
Method and edition, customer specification, profile basis, qualification or development objective, and exclusions.
Drawing or photos, axis map, hardware, torque, fixture geometry/material, bracket, and cable restraint.
Accelerometer locations, orientation, mounting, calibration, range, acquisition, filtering, and control tolerance.
Pulse time histories or SRS, damping/band where relevant, directions, event count, aborts, limiting, and deviations.
Pre/during/post power, load, target, outputs, analog values, diagnostics, communication, calibration, visual and seal checks.
Pass/fail limits, anomaly and retest history, disposition, date, reviewer, and report revision.
Product and process changes that require technical relevance review, customer approval, or requalification.
Warning signs: a headline g value without duration, no fixture or axis record, no actual pulse or spectrum, no sensor revision, no cable or connector condition, post-test-only function, unexplained repeats, or a report for a different mounting system.
Ready-to-use RFQ language
Specify the installed problem, not an inherited g number.
Give the supplier enough information to judge the shock source, mechanical interface, sensor function, and evidence level. A good response may recommend a stronger bracket, cable restraint, connector lock, different sensor, or representative sample test.
Use the industrial sensor supplier guide when comparing qualification and change-control capability.
Example specification
Shock durability requirement: Supplier shall identify the exact sensor model, revision, firmware/parameter set, cable or connector, bracket, fasteners, torque, orientation, target or medium, and operating state covered by the evidence. State the test method and edition, pulse or SRS definition, peak, duration or frequency band, damping where applicable, axes, directions, event count, fixture and control location. Provide actual input data, powered functional monitoring when continuous operation is required, pre/post performance results, visual and mechanical inspection, deviations/retests, report traceability, and product changes that trigger relevance review or requalification.
Illustrative engineering scenarios
The same “shock-resistant” sensor can behave differently by installation.
These examples are decision aids, not named customer cases or performance promises.
Photoelectric sensor loses output briefly
The body survives, but the connector cable pulls in one impact direction and creates a short interruption.
Test the production cordset, cable route, clamp, output, and supply.Inductive sensor target gap changes
The bracket flexes during a vehicle event and causes a false transition without permanent sensor damage.
Instrument the bracket and verify real target geometry and margin.Pressure zero shifts after impact
Communication remains online, but a mounting or PCB mode changes the measurement reference.
Run controlled pre/post multi-point calibration, not only a bus check.Cable entry leaks later
Shock creates a latent interface weakness that becomes visible only after temperature and moisture exposure.
Combine root-cause analysis with relevant ingress and thermal checks.A lighter bracket invalidates old evidence
The new boundary condition changes interface response even though the sensor order code stays the same.
Review mounting relevance and repeat the necessary characterization.
Application-fit review
Does existing shock evidence represent your installation?
Send the sensor configuration, mounting drawing, cable or connector design, target or medium, shock event, operating requirement, failure consequence, quantity, destination market, and evidence needs. xsz sensor can help identify the information required before model selection or sample validation.
Request a shock application review
Include these details
- Shock source and measured data if available
- Sensor model, output, range, and firmware
- Bracket, fasteners, torque, and orientation
- Cable route, connector, clamp, and external mass
- Target or process medium and sensing margin
- Required operation during and after the event
- Report, sampling, and change-control requirements
Frequently asked questions
Common questions about industrial sensor shock testing
What does shock testing prove for an industrial sensor?
It proves only that the identified sensor configuration met the stated shock profile and acceptance criteria under the documented mounting and operating conditions. It can reveal structural damage, intermittent faults, calibration shift, reset events, seal weakness, and loss of sensing function. It does not prove every installation or unrelated ratings.
Is shock testing the same as vibration testing?
No. Shock is a short transient event defined by a pulse or spectrum. Vibration is repeated oscillatory motion over frequency and time. Many rugged applications need both, but passing one does not automatically demonstrate performance in the other.
Does a higher shock g rating mean a more durable sensor?
Not necessarily. Peak acceleration without pulse shape, duration, frequency content, directions, event count, fixture, control point, cable condition, operating state, and acceptance limits is not a reliable comparison. Choose evidence that matches the installation.
Can a sensor pass a drop test but fail installed shock testing?
Yes. A free drop uses a different impact path, restraint, orientation, and pulse than a mounted sensor. The installed bracket, cable, connector, and target geometry can create loads that the drop does not reproduce.
Why should a sensor be powered during a shock test?
Power it when the application requires operation through the impact. Shock can create a brief output glitch, analog spike, power interruption, reset, or communication gap that disappears before post-test inspection. An unpowered test has a different mechanical-survival scope.
What is a shock response spectrum, or SRS?
An SRS describes the maximum response of ideal single-degree-of-freedom oscillators across frequency for a stated damping assumption. It is not one unique time waveform, so the report must state frequency band, damping or Q, tolerance, control location, and measured conformance.
What usually fails first in a sensor during shock?
There is no universal first-failure point. Common weak paths include brackets and mounting bosses, cable entries and connectors, PCB components and solder joints, sensing-element alignment, potting or adhesive interfaces, and seals. The result depends on the load path and orientation.
What should a buyer request in a shock-test report?
Request exact sensor and revision identity, method and edition, pulse or SRS, axes and event count, fixture and torque, cable and connector state, accelerometer locations, actual time histories or spectra, powered monitoring, pre/post results, acceptance criteria, deviations or repeats, and product-change status.
Technical references
Standards and primary engineering context
Use the applicable sector standard, exact sensor documentation, and a qualified risk assessment for final qualification decisions.
- IEC 60068-2-27:2008, Environmental testing - Test Ea and guidance: Shock.
- IEC 60068-2-31:2008, Rough handling shocks, primarily for equipment-type specimens.
- IEC 60749-10:2022, Mechanical shock for semiconductor devices and subassemblies.
- ISO 16750-3:2023, mechanical loads for road-vehicle electrical and electronic equipment at the specified mounting location.
- NASA SSRI Shock Testing Knowledge Base, pulse/SRS interface testing, fixture planning, and accelerometer placement.
- Analog Devices sensor enclosure and mounting article, mounting resonance and cable anchoring as system-response factors.
- Analog Devices AN-1045, an engineering example of attachment, resonance, connector, and cable protection considerations.