What Should a Laser Cleaning Machine Factory Acceptance Test Include?

The useful result of FAT is a decision about a particular machine, supported by records. A demonstration can show that a laser removes a patch of coating. FAT must also show which machine did the work, under which settings and conditions, whether the whole required area passed inspection, how the system behaved over the agreed duty, and what remains open before production.

What Must a Laser Cleaning Machine FAT Prove Before Shipment?

FAT compares the delivered unit with an approved specification and test protocol. It should establish that the contracted components and functions are present, the agreed cleaning result can be achieved on relevant workpieces, and the machine can complete the specified factory test without an unresolved critical fault. Each conclusion needs its own method and decision limit. A single statement that the machine “works normally” cannot tell a buyer whether a protected surface changed, a safety function failed, or a target output rate was missed.

This matrix is a way to organize a protocol, not a universal pass specification. The actual methods, tolerances, test duration and number of workpieces depend on the machine, the buyer's parts and the consequences of failure.

How Do FAT, SAT, and Process Qualification Differ?

FAT takes place before shipment, where the supplier can show the assembled machine and collect the evidence that can reasonably be obtained at the factory. SAT checks the delivered machine after transport and installation: site power, cooling, extraction ducting, guarding, controls, integration and any performance that depends on the buyer's environment. Process qualification asks a further question: will the controlled recipe repeatedly produce acceptable work with the actual production parts, operators, lot variation and inspection system?

The three gates should share definitions without pretending they share conditions. For example, a factory trial can verify cleaning on a buyer-approved sample. It cannot by itself prove that the installed extraction system captures contaminants in every position at the buyer's site. Put that site-dependent test in the SAT plan, with an owner and a completion criterion, instead of silently treating it as passed.

Why Is a Successful Cleaning Demonstration Not Enough?

A supplier may demonstrate removal on a flat, lightly contaminated coupon because it is easy to position and film. The buyer may need to clean a curved weldment with thick, variable coating while preserving a machined edge. Both observations can be true: the demonstration succeeds and the production task remains unproven. A FAT sample should represent the difficult but foreseeable conditions, not just the most photogenic result.

Likewise, the beam may be on for only part of a production cycle. Loading, fixturing, refocusing, multiple passes, inspection and rework all affect accepted output. The FAT protocol needs to say which of these actions the rate includes. That turns a visual demonstration into evidence relevant to purchasing.

What Should Buyers Agree Before the FAT Begins?

Write the protocol while the order can still be clarified. Link each test to the purchase specification, approved drawings and machine configuration. For every acceptance item, name the sample, operating condition, measurement or observation, permitted result, record format, witness and decision owner. Also decide what happens when a test cannot be completed or a result is borderline. Negotiating these points beside a running machine creates avoidable disputes about what was actually promised.

How Should the Machine Configuration and Software Version Be Frozen?

Record the laser source, beam-delivery and cleaning head, optics, controller, cooling arrangement, extraction interface, motion equipment, safety hardware, electrical supply, accessories and software or recipe versions that affect the agreed function. The exact fields depend on the build. Model names and serial numbers should be linked to the purchase order and, where appropriate, photographed or captured from records. A substitute source or scan head is a configuration change even if the cabinet looks unchanged.

Agree on a change rule. If the supplier replaces a performance-critical component or updates software after the sample trial, identify which earlier results remain valid and which must be repeated. The point is not to forbid changes; it is to prevent evidence collected on one configuration from being used to approve another without review.

How Should Representative Workpieces and Contamination Conditions Be Selected?

The sample set should cover the features that could change the answer: substrate and finish, contaminant chemistry and adhesion, layer thickness or severity, part geometry, access angle and the next operation. Record each sample's ID, condition and storage history when they matter. A standard rusted plate may help the supplier set up a machine, but it is not automatically equivalent to the buyer's coated casting or precision part.

If actual parts cannot be sent to the factory, agree on a controlled substitute and write down what it represents and what it does not. A final check may then have to move to SAT or process qualification. Do not label an uncorrelated demonstration coupon “representative” simply because it is made from the same base metal.

How Should Acceptance Criteria, Measurement Methods, and Retesting Rules Be Defined?

Separate the removal target from the protected condition. “Remove the coating” is incomplete if the buyer must also retain a specified roughness, dimension, edge, electrical contact or coating-ready surface. State who owns each limit, where it is measured, what instrument or method is used, and how an uncertain result is decided. A visual endpoint may be sufficient for some visible residue; it cannot by itself establish dissolved salts, adhesion strength or a hidden functional property.

The protocol should distinguish pass, fail, not tested and accepted deviation. Set the permitted corrective action, number or conditions of retests where relevant, and who approves a changed recipe or sample. If an instrument cannot resolve the agreed limit, that characteristic is not verified merely because its reading looks close.

How Should the Delivered Machine and Laser Output Be Verified?

Machine identity and optical performance are related but separate checks. Matching a nameplate to the order proves what was supplied. It does not prove the beam delivered the contractual quantity at the agreed measurement point. Conversely, one good power reading does not prove the head, controller, safety functions or software match the approved build.

Do the Components, Optics, Accessories, and Controls Match the Purchase Order?

Start with the configuration record and inspect the actual unit. Check critical model and serial identities, cable and fiber arrangement, lenses or scan head, working distance or fixture as specified, chiller or air-cooling configuration, extractor connection, power input, controls and supplied accessories. Confirm software revision and access to the accepted recipe. An accessory list matters because an absent nozzle, filter stage, fixture or cable can make the successful factory setup impossible to reproduce at the buyer's site.

Document discrepancies rather than correcting the paperwork from memory. A minor cosmetic variation and a different laser source do not carry the same risk. The change-control rule agreed before FAT determines whether an item can be accepted, must be corrected, or invalidates a prior test.

Which Laser Output Parameters Must Be Measured, and Which Can Be Verified by Records?

Measure the characteristics that are contractual and technically measurable in the agreed setup. A CW source may require delivered radiant power and stability over the specified load. A pulsed source may require average power, pulse energy, repetition rate, pulse duration or pulse-to-pulse stability; these are different quantities. For example, two pulse trains can have the same average power but different energy per pulse if their repetition rates differ. The screen's command value and a component datasheet describe settings or component capability, not necessarily output at the workpiece.

ISO 11554:2025 [1] describes test methods for radiant power, radiant energy and temporal characteristics of CW and pulsed laser beams. Its published scope does not prescribe a universal FAT tolerance for every cleaning machine. If the contract needs a beam measurement, specify the location, operating state, detector and procedure. Other characteristics can be verified by model-matched records when the contract permits that route; do not silently replace a promised measurement with a brochure value.

How Should Instruments, Calibration Records, and Measurement Conditions Be Documented?

Record the instrument and sensor ID, suitable wavelength and power or energy range, calibration status, any attenuator, measurement location, warm-up state, load, environmental condition and the number or duration of readings. Also record resolution and uncertainty where these affect the decision. An instrument that cannot safely receive the beam or distinguish a result near the limit is the wrong tool for that acceptance item.

Keep the raw readings as well as the calculated result. If an output value changes after the system warms, a single cold reading would hide the condition the buyer needed to assess. A disagreement should trigger the agreed repeat or alternate qualified method, not an undocumented adjustment of the pass limit.

How Do You Verify Cleaning Quality Without Damaging the Substrate?

“Without damaging” means meeting the part's agreed limits, not proving that no microscopic change of any kind occurred. A process can remove a coating yet leave discoloration, pits, altered texture, heat effects or lost material that matters to the next operation. The FAT should define both the removal endpoint and the maximum acceptable change to the underlying part, then use methods capable of resolving those conditions.

How Can You Verify Contaminant or Coating Removal Against an Agreed Endpoint?

Map the required cleaned area on the workpiece and identify areas that are easy to miss: edges, recesses, weld toes, corners and transitions. Inspect or measure at agreed locations after the part has cooled and been handled as it will be in practice. Depending on the contaminant and downstream requirement, the method might be controlled visual inspection, coating-thickness measurement, microscopy, a specified surface-cleanliness test or another process-specific analysis. Each method answers a different question.

Do not infer complete removal from a bright photograph. A thin transparent residue, soluble contaminant or material in a pit may remain while the surface appears clean. The buyer should choose the endpoint and method from the next process's requirement; the supplier should record the result for each sample and zone.

How Should Substrate Damage, Surface Condition, and Dimensional Limits Be Checked?

Measure the features the process could change and the part cannot afford to lose. A machined sealing face may need a dimensional and roughness check; a painted panel may need color or gloss comparison; a thin part may need distortion assessment. Compare the cleaned area with a defined baseline or reference sample using the same measurement method. A difference is not automatically a failure—the agreed tolerance determines the decision.

If the relevant property cannot be checked at the supplier's factory, record it as an open qualification item rather than writing “no damage observed.” The more sensitive the substrate or finish, the less useful an unqualified visual judgment becomes.

Which Difficult Areas and Downstream Requirements Need Separate Verification?

A flat coupon does not establish access to a blind feature or consistent cleaning around a corner. Use the production-intent head, standoff, fixture and extraction arrangement on representative geometry. Mark any excluded zone or manual touch-up explicitly. If the required feature cannot be reached or inspected, the FAT has found a limitation that must be resolved or assigned to another process.

Downstream welding, painting, bonding, sealing or electrical contact may require its own tests. The FAT can collect appropriate cleaned samples and document their lineage, but a passed cleaning appearance test does not automatically qualify the later weld or coating. Assign each downstream test to FAT, SAT or process qualification according to where its true conditions can be reproduced.

How Should Cleaning Repeatability and Production Throughput Be Tested?

A single clean sample shows that a result is possible. Production needs that result to remain acceptable as workpieces, contamination and operating time vary. The FAT should therefore define a representative run and count only output that passes the agreed inspection. Scan speed alone does not include rework, part handling or downtime.

How Many Representative Workpieces Should Be Tested, and How Should Variation Be Recorded?

There is no universal FAT sample count. Choose the number and mix before testing from the expected variability and the cost of a missed failure. Include the relevant material grades, coating or contaminant ranges, part geometries and difficult zones. A few convenient flat coupons are inadequate if production parts contain deep recesses or variable deposits. For each workpiece, record its identity, initial condition, recipe, pass count and final acceptance result. Keep both failures and successes in the record.

If one sample needs a different recipe, decide whether that variation is permitted in production. A revised setting that works on the last sample does not erase the failure on the first; repeat the agreed part of the trial using the revised configuration and record why it changed.

How Do You Calculate Accepted Throughput Across the Complete Cycle?

Define the clock start and stop points around the operation the buyer will actually run. A complete cycle may include loading, locating, cleaning, repositioning, unloading, inspection and ordinary changeover. Then divide the accepted area or accepted parts by the corresponding elapsed time. For example, if a trial processes 20 parts in 50 minutes and 18 pass the agreed inspection without rework, accepted throughput for that observed cycle is 18 ÷ (50/60) = 21.6 parts per hour. These figures are illustrative arithmetic, not an Oceanplayer machine result or a production guarantee.

Also report laser-on time, number of passes and rework time separately. That lets the buyer see whether the apparent bottleneck comes from beam interaction, access, handling or quality variation. If the factory fixture differs from the intended production fixture, mark the resulting rate as a factory observation and verify the installed line again during SAT.

How Should Sustained Operation, Alarms, Downtime, and Recovery Be Evaluated?

Run the equipment long enough to observe the agreed duty cycle and likely heat or extraction load; the duration should come from the purchase specification and intended operation, not a generic number of hours. Log the start and stop times, alarms, interruptions, fault causes and recovery steps. Confirm that a controlled restart restores the approved recipe and that a failed part is identified rather than silently counted as accepted output.

A sustained run is not an accelerated lifetime test. It checks whether the contracted system can operate under the chosen trial conditions and whether deviations are visible and manageable. Longer-term availability belongs to a separate service or production agreement if the buyer needs it.

Which Safety and Auxiliary Systems Should Be Included in FAT?

The safety test list comes from the actual machine, its operating modes and risk assessment. A hand-held open process and an enclosed automated cell do not have identical exposure paths. ISO 12100:2010 provides risk-assessment principles, ISO 11553-1:2020 addresses laser processing machines, and IEC 60825-1:2014 addresses laser product classification and requirements. These scopes guide the assessment; they do not substitute for the equipment-specific test plan. [2][3][4]

How Should Laser Guards, Interlocks, Emergency Stops, and Safe Restart Be Tested?

Witness the safety functions listed for the supplied configuration. Check the defined response to opening a guard or access door, pressing each relevant emergency-stop device, losing a necessary control signal, and attempting an unauthorized or unexpected restart. Test both normal operation and applicable setup or service modes, because a safe production cycle does not prove a safe maintenance state. Record the test method, expected safe state, observed response and reset sequence.

Assess possible direct, reflected and scattered beam paths, especially with reflective workpieces and open access. Eye protection, barriers, beam termination, access control and training must match the accessible emission and risk assessment. ISO 11553-2:2026 has a specific scope for hand-held or hand-operated laser processing machines; it should not be cited as if every fixed cell were hand-held. [5]

How Should Fume Extraction Be Evaluated for the Agreed Material and Cleaning Process?

Laser cleaning transfers removed material into particles and fumes that must be controlled. The hazard depends on the contaminant, coating and underlying material; an unknown coating needs identification before a trial can establish an adequate extraction plan. Check that the intended hood, enclosure, airflow indication, filter arrangement and alarm responses are present and function as specified for the tested process. A generic fan operating is not evidence that exposure at every future worksite is controlled. DGUV's hand-held laser cleaning guidance discusses the need to assess and capture released material within its stated scope. [6]

The buyer's installed ducting, room airflow, make-up air, filter maintenance and local exposure assessment remain site matters. Keep the FAT result tied to its tested material and extraction arrangement, and put any untested coating or work area on the SAT or qualification list.

How Should Cooling, Electrical Systems, Motion, and Control Interfaces Be Checked?

Check the auxiliary equipment actually supplied: cooling capacity and alarms, electrical protection and labeling, motion limits and homing, fixture signals, recipe access, error messages, and any agreed PLC or production-line interface. Exercise the operating states that the buyer expects to use. IEC 60204-1:2016 with Amendment 1:2021 concerns electrical equipment of machines that are not portable by hand while working. Assess a portable hand-held configuration separately before applying that standard; test details also depend on the actual machine and market. [7]

Do not combine all checks into a single “system works” sign-off. A cleaning pass can succeed while a coolant alarm, guard signal or data interface remains untested. Note which functions require the customer's power supply, network or upstream equipment and therefore remain open until SAT.

What FAT Records and Handover Documents Should the Buyer Receive?

An acceptance result should be reproducible from the record. The report needs to connect the exact machine, samples and settings to each pass or failure, so a later software change or replacement optic does not make the original result ambiguous.

What Should the FAT Report Record for Each Test and Acceptance Criterion?

Use a test line for each requirement: criterion and limit, method, sample or machine ID, operating mode, recipe and software version, instrument and calibration identity, environmental or fixture conditions where relevant, raw reading, calculated result, pass or fail, date and witnesses. Attach photographs only when they document a defined observation; they do not replace a required measurement. Retain data from failed and repeated runs, with the reason for every retest.

A useful report lets a buyer answer three questions without asking the supplier to reconstruct the demonstration: What was tested? Under which conditions? Against which agreed limit? If a condition was not tested, label it not tested, not passed.

Which Manuals, Drawings, Spare Parts Lists, and Maintenance Records Should Be Handed Over?

Match the handover package to the purchased configuration and contract. It may include the machine identification and as-built configuration, operating and safety instructions, relevant electrical and pneumatic drawings, optical or cooling system information, maintenance schedule, consumable and spare-parts list, software or recipe backup procedure, calibration records, training record and supplier contact path. The buyer needs enough information to install, operate, maintain and troubleshoot the delivered system safely. Confirm language, file format and revision status before shipment.

How Should Open Deviations and Outstanding Deliverables Be Recorded?

Maintain a deviation log with the requirement, observed result, impact, owner, corrective action, due date and retest evidence. Separate a documentation item from a performance or safety failure. A missing drawing can sometimes be closed through a dated deliverable; an unverified interlock or failed surface criterion cannot be made acceptable by changing the wording of the report. Both parties should agree who closes each item and which acceptance gate it affects.

When Should a Buyer Accept, Retest, or Stop Shipment?

The decision should follow the agreed criteria, not the visual appeal of a demonstration. A complete FAT report gives the buyer a basis to release, conditionally release, request corrective action or withhold shipment. Acceptance of a factory result does not waive later site or process requirements unless the contract explicitly says so.

Which Results Allow Shipment Approval?

Release is reasonable when the contracted configuration is identified, all mandatory FAT criteria pass, required safety functions are verified, the handover package is complete to the agreed level, and the buyer has signed the test record. Clearly list tests reserved for SAT and process qualification. A factory pass should have a defined scope rather than a broad statement that the machine is suitable for every workpiece.

When Is Corrective Action and a Witnessed Retest Required?

If a sample fails the cleaning endpoint, a measured output falls outside its agreed tolerance, or a required function fails, record the result before making changes. The supplier should identify cause and corrective action, then repeat the affected tests under the agreed conditions. A new optic, software version, fixture or recipe may change more than one result, so decide whether related tests also need to be repeated. The retest record should show both the original and final results.

How Should Conditional Acceptance and Unresolved Deviations Be Handled?

Conditional acceptance is a documented agreement about a specific open item, its deadline and the evidence needed to close it. It is not an undocumented pass. Do not release a machine with an unresolved safety-critical function or a failed mandatory cleaning requirement merely because a later site trial is planned. For other items, the buyer and supplier can allocate closure to SAT if the contract permits and the remaining risk is understood. Record who has shipment authority and the precise conditions of that release.

Frequently Asked Questions

Can a Supplier's Standard Sample Replace the Buyer's Actual Workpiece?

Only when it represents the material, contamination, geometry and acceptance requirement the buyer needs to prove. A standard coupon can check a basic machine function, but it cannot by itself qualify a different coating, recess or finish. Bring actual parts or agree on a documented representative surrogate and its limits.

How Long Should a Laser Cleaning Machine FAT Last?

Long enough to execute the agreed test matrix, including representative samples, measurement, repeatability, safety functions and deviation review. There is no universally valid duration. Define the scope, sample count and sustained-run condition before scheduling the FAT.

Does a Passed FAT Guarantee Performance at the Customer's Site?

No. The factory test verifies the specified machine under recorded factory conditions. Site utilities, fixtures, airflow, part variation, operators and line interfaces can change the result. Use SAT and, where needed, process qualification to verify those installed conditions.

Should the Buyer Witness the FAT in Person or Remotely?

Either can work if the test plan defines what the buyer must observe and how raw results will be shared. For a remote witness, use clear views of the machine identity, sample condition, test sequence, instrument readings and safety-function response, with a way to pause and request a repeat. Video alone is weaker than a complete signed record with traceable data.

Technical References

1. ISO 11554:2025 — Optics and photonics — Lasers and laser-related equipment — Test methods for laser beam radiant power, radiant energy and temporal characteristics. Used for the scope of output measurement; no generic FAT limits are inferred.
2. ISO 12100:2010 — Safety of machinery — General principles for design — Risk assessment and risk reduction. Used for risk-assessment framing.
3. ISO 11553-1:2020 — Safety of machinery — Laser processing machines — Part 1: Laser safety requirements. Used for laser processing machine safety scope.
4. IEC 60825-1:2014 — Safety of laser products — Part 1: Equipment classification and requirements. Used for accessible-emission classification scope.
5. ISO 11553-2:2026 — Safety of machinery — Laser processing machines — Part 2: Safety requirements for hand-held or hand-operated laser processing machines. Cited only for the hand-held/hand-operated scope.
6. DGUV FBHM-139 — Blasting work, cleaning and decoating with laser radiation. Used for hand-held laser cleaning safety and extraction context.
7. IEC 60204-1:2016+AMD1:2021 — Safety of machinery — Electrical equipment of machines — Part 1: General requirements. Used for electrical-equipment scope.