FAQ

Testing turnaround depends on the combination of test items, sample condition, and the laboratory's current schedule. Different items vary widely—for example, ESD and accelerated aging take very different amounts of time, so there is no single fixed number of days.

When submitting samples, please also tell us your expected delivery date. We will confirm a feasible plan based on current scheduling and keep you updated at each milestone. The schedule is subject to mutual confirmation.

Scheduling is negotiated around your deadline. Tell us the expected date when submitting the request; we assess current capacity and project mix, then reply with a feasible arrangement. Where the project can be split, the items blocking your next milestone go first.

The schedule follows the milestones both sides confirm, and progress is reported at each one.

The standard flow: requirement discussion → confirm the test plan and standards → ship samples or arrange pickup → lab scheduling and testing → report issue. The submission guide and sample list are sent once the scope is confirmed, so you never have to figure it out yourself.

Three things before shipping: test items and applicable standards, sample quantity and condition requirements, and the intended use of the report. Shipping before these are fixed often means too few samples or a sample state that does not meet test conditions, forcing a re-submission.

For full units and large assemblies, contact us in advance so we can plan space, lifting and protection first.

Yes. We recommend running pre-scan testing on the key items first to identify risks, then arranging the full program once the risk points are clear—this avoids unnecessary spend. Issues found at the pre-scan stage also give you time to prepare fixes.

Yes. We provide testing together with global product certification support, covering CE, FCC, UL, CCC, CB and more than 30 countries with 60+ certification programs. Our in-house CBTL can issue CB reports—one test, multiple countries. Formal certification is carried out by accredited certification bodies.

CMA (China Inspection Body and Laboratory Mandatory Approval) and CNAS (laboratory accreditation) — with approximately 10,000 m² of lab space and 500+ instruments. All specialized labs can be visited by appointment, with on-site witnessed testing available.

Yes. All six specialized laboratories can be visited by appointment, and clients may request to witness key test items on site. Please book and register with us in advance; visitor parking is available on campus.

Before witnessing, we recommend confirming the witnessed items and time window so we can arrange the workstation, records, and accompanying staff.

Three options: courier (follow our submission guide and include the application form and sample list), pickup (engineer pickup can be booked in Shenzhen; a dedicated vehicle around Dongguan), and large samples (full units and big assemblies—contact us in advance to plan space and lifting).

In R&D, pre-scan testing is the focus: identify risk points, verify design margin, and keep the cost of iteration low. In mass production, the emphasis shifts to batch consistency and compliance with OEM validation, with formal reports usable for customer acceptance. We recommend a test combination based on the stage you are in.

Quoted per project, driven by four variables: sample quantity, the combination of test items, the standard revision used, and the intended use of the report (R&D pre-scan / customer acceptance / certification support). The more items tested on the same product, the lower the cost per item.

When asking for a quotation, state the product model, target standards and sample count in one go, so the engineer can return an actionable quotation instead of a vague price range.

Testing is not a commodity. The same product tested for 3 items or 12, with 1 sample or 5, against an old or new standard revision, can differ several-fold in cost. A flat unit-price list tempts you to budget by single items and miss the total.

Our practice: first an itemized list and quotation—each test item, its standard, and its fee—so you can verify and trim line by line.

The quotation lists test items and their standards line by line, with report fees and sample handling/disposal stated explicitly; on-site witnessing, pickup, and non-standard items are priced separately rather than buried in the total.

If sample condition forces additional items during execution, we confirm scope and cost with you before starting—never test first and bill later.

Yes—and that is the recommended order. Send the product category, target market, and customer or OEM specification requirements; the engineer returns an item mapping: which tests, against which standards, and which items can wait. Quotation comes after the scope is agreed.

Quoting on an unclear scope usually means re-quoting after the changes—wasted effort.

Yes—both VAT special and general invoices, issued against the company title and tax ID on the application form. If the invoice should ship together with the report, note it when commissioning.

Please confirm title and tax ID when placing the order; changing the title after the report is issued requires a void-and-reissue process.

Yes, we sign. Sample information, test data, drawings and report contents are handled under confidentiality—no external disclosure and no use in case marketing without your written consent.

For an NDA, send your template for stamping, or use our standard version after your legal review.

Corporate bank transfer is standard; long-term clients can apply for periodic settlement. After the order is confirmed, prepayment or milestone-based settlement follows the terms written into the quotation and application form.

For certification support projects, certification-body fees and testing fees are listed separately so the total stays readable.

Four sets dominate: CISPR 25 / GB 18655 (emission limits and immunity test conditions for components—GB 18655 is the Chinese adoption), ISO 11452 (EMC measurement methods for vehicles and large components), ISO 10605 (electrostatic discharge), and UN ECE R10 / GB 30512 (whole-vehicle type approval for EU export).

Selection follows the customer or OEM specification; many OEMs impose stricter in-house standards, which take precedence per the purchasing technical agreement.

Samples must be fully functional: powered on, entering the specified operating mode, with the matched harnesses and loads. Vehicle components are set up per the OEM-specified harness length, ground points and load impedance—otherwise results are not comparable.

Bare boards or semi-finished units generally cannot complete emission and immunity items; if staged verification is needed, confirm an alternative test plan and acceptance basis with the engineer first.

In practice conducted emission needs no anechoic chamber and has a lower entry barrier, so it usually goes first. But radiated emission failures often involve layout and structure, with a larger blast radius. We recommend running both in the pre-scan stage to map the whole problem at once.

First separate harness contribution from enclosure radiation: sweep a near-field probe along enclosure seams and cable entry points to find hot spots, then measure common-mode current on the harness with a current clamp. Root causes typically concentrate in clock and switching-supply routing, insufficient input filtering, seam shielding, and shield-braid termination workmanship.

After locating, remediation is guided by the source–path–victim triad. Getting in at the pre-scan stage costs far less than reworking after design freeze.

We provide remediation direction and verification support, but design changes are implemented by your R&D team—our job is locating the problem, explaining the mechanism, and verifying the effect, not redesigning for you.

The usual split: we deliver locating data and failure mechanisms; your team adjusts filtering, shielding, routing and bonding; then a verification round compares before/after. Only with both datasets side by side can you confirm the fix actually worked.

Per ISO 10605, the level follows the customer specification or OEM requirement—common settings are ±4 kV contact and ±8 kV air discharge; there are powered and unpowered modes, and discharge points cover all user-accessible enclosure areas, keys and connectors.

At the pre-scan stage, verify at the upper limit of the customer specification to leave design margin.

Both are immunity tests with different injection: BCI per ISO 11452-4 couples disturbance current into the harness with an injection clamp, covering lower frequencies and simulating on-board conducted coupling; RI per ISO 11452-2 illuminates the EUT with an antenna field in a chamber, covering higher frequencies and simulating spatial radiation.

The bands are complementary—automotive components usually need both.

Vehicle EMC (e.g. GB/T 34660, ECE R10) assesses the whole vehicle; component EMC (e.g. CISPR 25) assesses the single unit. Component compliance is the foundation, but the vehicle result also depends on placement, grounding and harness routing.

Suppliers typically validate against the OEM component standard; the vehicle maker then confirms at vehicle level.

Generally no. R&D pre-scan data exists to identify risk and guide remediation; formal submission requires executing the full program under the accreditation process with a formal report. Treat pre-scan as a health check—solve problems before the formal round and avoid paying twice.

Thermal shock (GB/T 2423.15 / ISO 16750-4) is a fast two-chamber transfer, targeting solder cracking and seal failure from mismatched thermal expansion. Thermal cycling (GB/T 2423.22) is single-chamber gradual ramping at lower rates, targeting parameter drift and cumulative fatigue.

Choose per the customer specification and target failure mode.

Sequence affects conclusions and is not shuffled casually. The common order: conditioning → initial functional and visual check → mechanical stress (vibration, shock) → climatic (thermal cycling, shock, damp heat) → corrosion (salt spray, gas) → final functional and visual retest.

Mechanical stress first tends to expose solder and structural defects; climatic and corrosion later, so early damage does not mask later failure modes. Where the customer specification fixes the order, it prevails.

Per ISO 16750-3, the PSD curve follows mounting location (engine compartment, chassis, body) and target service mileage, applied axis by axis. If the customer specification defines a profile, it prevails; otherwise use the typical spectra in the standard annex, assessed against real vehicle conditions.

Neutral salt spray per GB/T 2423.17, commonly 48 h or 96 h; cyclic salt spray adds dry/wet alternation and corrodes closer to reality. The setting follows the anti-corrosion requirement and customer specification—parts with mating interfaces, like connectors, often pair the rating with a contact-resistance criterion rather than appearance alone.

Flowing mixed gas corrosion (e.g. GB/T 2423.51) simulates sulfur- and nitrogen-bearing micro-corrosive environments and is more sensitive for fine-pitch solder joints and plating on PCBs and connectors. Salt spray simulates marine and road-salt environments, better suited to assemblies and structural parts. The failure mechanisms differ; high-end automotive parts sometimes need both.

Per GB/T 4208, the first digit is dust (6 = dust-tight) and the second is water (5 = water jets, 7 = short immersion). Exterior body parts commonly require IP67; cabin parts are often IP65. The customer specification prevails.

Yes. IP rating is judged not only on water ingress but on post-test function, internal condensation and deposits. Per GB/T 4208, opening the enclosure for inspection and functional retest are both part of the criteria.

For parts with breather valves or seals, capture an airtightness or functional baseline before and after, to distinguish design issues from assembly issues.

VOC sampling splits into the bag method (whole part heat-sealed in a bag) and the chamber method (whole unit or assembly in a chamber), analyzing benzene series and aldehydes/ketones. Odor is rated 1–6 per VDA 270 (1 = odorless). Interior parts and display modules often require both; limits follow the OEM standard.

Acceleration factors are derived from Arrhenius (temperature) or Coffin-Manson (cycling) models against real service temperature and target life, then the duration specified by the customer standard is executed—duration is a standard parameter, not a delivery time.

Model and activation energy values need a basis (customer spec, device datasheet, or historical data); without one, run the standard recommended values and state the assumption in the report—the conclusion holds only under that assumption.

The standard path: phenomenon confirmation → external inspection → non-destructive testing (X-ray, ultrasonic) → electrical retest → destructive analysis (cross-section, dye-and-pry, SEM/EDS) → root-cause conclusion with an evidence-chain report. Every step is documented and the conclusion must be reproducible. A failed unit paired with a known-good reference dramatically speeds up localization.

The failed unit itself (kept in original state—do not disassemble or grind it yourself), a known-good unit from the same batch as reference, a description of the failure (when, under what conditions, at what rate), and any preliminary checks already done. The more complete the information, the shorter the analysis path.

Yes, but the analyzable scope narrows. Once the original fracture surface, burn marks, plating and interfaces are disturbed, many failure mechanisms can no longer be determined, and the result degenerates to "no anomaly found".

The first move on receiving a failed unit is to leave it alone: no disassembly, no grinding, no cleaning, no high current. Photograph the appearance and mounting position first, then send it in.

Four typical classes: cracking (mechanical stress or thermal fatigue), cold/open joints and poor wetting (process window drift), excessive IMC growth (long high-temperature service), and CAF conductive anodic filament (humidity plus bias). Different modes point to completely different improvements—cross-section and X-ray are the usual discriminators.

Two steps: containment and stratification. First stratify defects by time, line, material lot and station to find the dimension with the highest concentration; then run failure analysis on the stratified samples to decide between insufficient design margin, process window drift, or incoming material variation.

Single-unit analysis answers "how did this one die"; batch analysis answers "why did many die at once". Different methods—do not mix them.

The report delivers the failure mechanism, the evidence chain, and directions that can be excluded. Responsibility is negotiated between supplier and customer based on the report and process records, or ruled on by a third party. We do not make liability determinations.

For a sharper conclusion boundary, provide the batch process parameters and incoming inspection records—more evidence means more can be excluded.

Phenomenon and background, sample and reference unit information, methods and raw data (appearance, X-ray, cross-section, SEM/EDS spectra), the failure mechanism determination, the evidence chain, and actionable improvement directions.

Original images and test conditions are retained for your reproduction; conclusions rest only on measured evidence, without unsupported speculation.

A test report is data-centric—measured values and verdicts, mostly for R&D pre-scan and process records. An inspection report is issued under the accreditation process and is usable for formal scenarios such as customer acceptance and supply-chain audits. Confirm the intended use before commissioning, to avoid redoing it with the wrong type.

Electronic by default (PDF with signature and seal); paper copies are stated at commissioning and shipped with the report. Chinese and English versions can be issued on request; the English version follows the Chinese original.

If you need data first for internal review, a staged delivery arrangement can be agreed separately.

A report has no statutory validity period—it attests to the submitted sample's performance under the test conditions. The accepting party (customer, OEM, certification body, tender) sets its own limits, usually tied to product version and standard revision.

After design, critical component or supplier changes, the original report generally no longer represents the current product and should be reassessed.

No. The CB report is test data issued by a CBTL (CB-scheme-accredited lab) against IEC standards; the CB certificate is issued by an NCB (a national certification body) on top of the report. One CB report can convert into certificates for multiple countries without retesting; the conversion is completed by an accredited certification body.

The difference is acceptance scope, not the testing itself. Reports carrying CMA / CNAS marks carry evidentiary weight within the accredited scope; an OEM-recognized lab additionally meets that OEM's specific requirements (method, equipment, criteria, report format).

Before commissioning, confirm who reads the report: for customer acceptance, check the accreditation scope; for an OEM, check their recognized-lab list and supplier handbook.

It depends on the accepting party. Most OEMs and certification bodies apply "the version in force at commissioning"; if the customer specifies the old version, the report simply states the standard number and revision. Where the revision gap is large (e.g. limit changes), we recommend re-verifying key items against the new version.

Priority order: customer technical agreement and OEM specification > mandatory standards applicable to the product > common international standards (IEC / ISO). For export products, also the target-market regulations. When unsure, send the product category, target market and customer list to the engineer—an item mapping comes first, then execution.