Frequently Asked Questions about the registration of medical device and IVDs in ChinaBelow you will find answers to questions we get asked by clients the most about registering medical devices or IVDs in China. 1 Where can we access Chinese standards in English? There is still no official electrical version for standards. All Chinese standards are only available in paper for sale. We can translate them for you into EN and we can search for applicable standards for your particular product published from different governing bodies. Occasionally the NMPA publishes lists of standards and guidelines. These can be a helpful starting point. 2 Are overseas devices always classified as Class II or III even if Class I in EU/US? No, it depends on the device. There are many overseas manufacturers with Class I devices. However, the China classification system is more conservative than many other countries, so it is often the case that a class I product in the home country is class II in China. Both domestic and foreign companies face the same requirements. 3 Labelling - my QA prohibits printing of certain data on my Chinese label (I would like instead to simply state that the user should refer to English label). All MD or their packaging must carry a standardized Chinese label. If the label has limitations in size it has to contain at least the following information: Name, model and specification of the product, production date, shelf life or expiry date, and the label must clearly indicate the phrase "see operating instructions for further details". Please contact us for our experts to check your label. We provide Chinese label templates for our registration customers. 4 What is the NMPA website to check on products registered with the NMPA? Available in Chinese only, but useful for checking up on your own or others’ product registrations: NMPA database 5 How detailed does the PTR need to be - should it include testing features? The PTR (Product Technical Requirements) lists all important technical parameters of the device and the related Chinese standards that cover these parameters. Test reports are not required in the initial PTR version – instead this will be covered in the test lab report. The PTR guidance document relates to formatting features and generally intricate testing details won't be required. The PTR is one of the most important documents for the China registration. It is annexed to the NMPA certificate and is equally important as the certificate. 6 Can you share a copy of the exemption catalogue? This is not one document but a series of regulations released by NMPA/SAMR. Please contact us and we will check the clinical trial exemption catalogue for you. 7 For the intravascular catheter products listed in the "Catalogue of Medical Devices Exempt from Clinical Evaluation" (hereinafter referred to as the "Catalogue"), the enterprise has completed the simulated use test of the declared products, must it carry out a comparative study on the simulated use of the compared products? For intravascular catheter products included in the "Catalogue", the registration applicant shall submit the relevant information of the declared product and the comparison data described in the "Catalogue" and the comparison description of the declared product with the medical devices in the "Catalogue" that have been approved for domestic registration. In view of the differences between the declared products and the comparison products, it is appropriate to submit relevant analysis and research data to prove that the declared products have basic equality with the products described in the Catalog. When the main material (including trade name/brand) and main structure of the declared product are different from the products that have been approved for domestic registration in the Catalogue, and the use performance is affected, it is appropriate to conduct a simulation and comparative use study on the two. 8 When and how to submit a medical device clinical trial database? According to the NMPA 's “Announcement on the publication of Medical device registration application data requirements and approval Certification Document Format” (No. 121 of 2021), since January 1, 2022, medical devices undergoing clinical evaluation through the clinical trial path need to submit clinical trial database when registering. This requirement applies to clinical trials of medical devices carried out for the purpose of product registration, and the clinical trials of medical devices carried out by the applicant at home and abroad are required to submit to the clinical trial database.The "Guidelines for Registration Review of Medical Device Clinical Trial Data Submission Requirements" provides guidance and specific requirements for the submission of clinical trial databases. Applicants should submit original databases, analytical databases, procedural codes and illustrative documents as required by the Guidelines.9 How to apply if the contents of the medical device manual change? According to the Regulations on the Management of Medical Device Specifications and Labels (Order No. 6 of the General Administration), if a registered medical device has undergone a registration change, the applicant shall modify the specification and label according to the change document after obtaining the change document. If the contents of the instructions that are not within the scope of the change registration are changed, they can be changed through the notification procedure of the change of the medical device instructions. When the registrant submits the application for notification of the change of the medical device instructions, the supporting materials for the change of the contents are submitted together. If the registrant does not provide corresponding supporting information or insufficient supporting information during the formal review process, the registrant will be informed of the specific problems existing in the declaration information and the information required to be submitted by the registrant through supplementary comments during the formal review. 10 When evaluating the service life of an active product, can the service life of its core components be evaluated only instead of the service life evaluation of the product?The service life evaluation of the active product shall be the whole machine evaluation, and all components contained in the product shall be included in the whole machine evaluation. After analysis, if some parts do not affect the service life of the whole machine, it is necessary to explain the reason. The evaluation of the service life of the core components can not replace the evaluation of the whole machine, but can be used as supporting evidence for the evaluation of the whole machine. 11 How to submit an evaluation for virus inactivation of animal-derived products?The risk control of infection viruses and infectious agents should be at least from the source control and process control. In order to ensure the controllability of risks, enterprises should establish a special control and traceability system for animal origin risk factors in the production quality system in accordance with the relevant requirements of medical device production quality management norms. Steps for virus inactivation/removal should be considered in the production process of animal-derived materials or medical devices. Risk analysis, description of the process for inactivating and removing viruses and/or infectious agents in the production process and validation data or relevant data should be submitted. For YY/T 0771.1 / ISO 22442-1 Medical Devices of Animal origin Part 1: Risk Management Applications， For tallow derivatives, animal carbonates and amino acids mentioned in the Appendix, data for validation of virus removal/inactivation effectiveness of the treatment process may no longer be submitted if it is demonstrated that the treatment process complies with the relevant requirements in the Appendix to YY/T 0771.1 / ISO 22442-1. 12 For separately registered hosts and accessories, if the co-use relationship is already clear in the information in the registration certificate, do the registration certificates of both hosts and accessories need to be changed when the co-use combination is added? For the specific host and accessories used together, when the host and accessories are declared separately, it is necessary to clarify the relationship between the use of each other, and reflect the relevant information of the product used together in the information contained in the registration certificate (such as the manufacturer, model specifications, software version, etc.). When a combination is added, the combination can be regarded as having been evaluated if the combination is clearly stated in the registration certificate of either party, and the other party only needs to make simple changes without repeatedly submitting the overall verification data and the research data jointly used by both parties. If the host is expected to be used with multiple accessories, but only some of the specific accessories are applied for use in the current registration unit, the scope of application can be stated as "Use with XX accessories and other accessories approved for use with this product" in the application. 13 What are the stoage requirements for stability study of in vitro diagnostic reagents? In vitro diagnostic reagent stability is the ability to maintain its performance characteristics within manufacturer specified limits. When studying the stability of reagents, full consideration should be given to variables that may affect the properties or effects of reagents, as well as changes in environmental factors, including the worst case. During the study, reagents shall be stored under conditions specified by the manufacturer, which are based on the capabilities of the test equipment or the intended storage conditions of the product, and which shall adequately verify the stability of the product under the most adverse conditions. The results of the study should demonstrate that the declared product can meet the stability requirements under the stated storage conditions and time. It is recommended that the applicant specify the specific range of storage conditions in the study data and stability claim, such as "stored at 2~8℃", and it is not recommended to use "refrigerated", "frozen", "room temperature" and other uncertain words to describe storage temperature. 14Whether the performance indicators of the product technical requirements of the in vitro diagnostic reagent must be included in the "stability" indicator? According to the "Principles of the Product Technical Requirements of Medical Device" (Notice No. 8, 2022) "4.Performance Indicator Requirements" example, "Shelf life of medical devices" belongs to "research and evaluation content not recommended to be specified in technical requirements performance indicators". This proposal is also applicable to the technical requirements of the in vitro diagnostic reagent. "Stability" may not be included in the performance indicators of the product technical requirements of in vitro diagnostic reagent. 15 Whether the results of the interference test of qualitative testing reagents can only be represented by negative and positive? The interference test generally uses a pairing comparison method, which compares the differences between samples that contain high concentration interference substances and noncontaining or normally concentrated interference substance samples (control) test results. For qualitative detection reagents with quantitionless data, interference test results can only be expressed as negative and positive, but it should be noted that research samples should contain weak positive levels.. For qualitative detection reagents based on quantitative data (such as OD value, Ct value or counting results, etc.) for threshold judgment, it is recommended to conduct difference analysis on quantitative data, instead of only using negative and positive to indicate the results of interference test. 16What are the key factors that should be considered for the samples stability of in vitro diagnostic reagent? The selection of the sample concentration should be focused, at least containing negative samples, weak positive samples, and medium/strong positive samples to examine the stability of different concentration samples and affect whether the detection will have. 17 Bland~altman analysis precautions of in vitro diagnostic reagent quantitative test results Bland~Altman analysis is generally used to evaluate the consistency of paired quantitative test results. In the Bland~Altman analysis of quantitative test results of in vitro diagnostic reagents, not only the consistency limit should be calculated according to the deviation value of test results, but also the appropriate acceptable criteria should be set according to clinical requirements. Evaluate whether the conformance limits are within acceptable standards. The setting of clinically acceptable standards should be based on reasonable evidence. 18 In the circumstance where reagents and their supporting instruments are to undergo clinical trials concurrently, can the same set of clinical data be used for the registration of both of their separate registrations? Would there be any issues to be aware of? In general, the completion of IVD reagent sample testing requires the support of applicable supplementary instruments. In the case where said supporting instruments have also yet to acquire marketing approval, the clinical trial of the IVD reagent should be performed with its applicable devices. Here the registration of the IVD reagent and its supplementary devices can share the same set of clinical data and documentation. However, the regulations applicable to reagent registration differ from that of its complementary devices, which is why they should be registered as separate units in the registration process. Aspects of clinical trial design and document preparation to be noted are as follows: ethical approval should clearly state the clinical trial that is being approved, including the declared reagents and supporting devices; the clinical trial protocols, summaries, report title, and content should include both the reagent and the devices; the main text of the content should clearly state the specifications of the reagent and devices; the clinical trial protocol should simultaneously encompass all evaluating indexes and methods for the reagent and devices; the clinical trial summary and report should cover all information relevant to the clinical evaluation of the reagent and devices, to the extent where it suffices the requirements for marketing clinical evaluation. 19 What things to pay attention to in the submission of IVD reagent clinical trial databases? As required of declaration materials, all IVD reagents undergoing clinical evaluation via the clinical trial route should submit their clinical trial database, as of January 1st, 2022. Applicants should strictly follow requirements on the correct submission of clinical trial databases outlined in “Guidelines for the Submission of Clinical Trial Data for Registration Review of IVD Reagents”. The clinical trial database should include the raw database, the analytical database, explanatory documents, and the program code (if applicable). The raw database refers to all cases and sample information enrolled in the clinical trial in accordance with the protocol. The analytical database refers to a database generated with input from the raw database in ways that facilitate statistical analysis, including the cases and sample information corresponding to the statistical analysis. The explanatory document should include at least a data explanation document and a statistical analysis document. If program code is used in database administration or statistical analysis, said program code should be provided. 20 What are the main points of focus concerning the IFU of IVD reagent in clinical trials ? In the design and implementation of IVD reagent clinical trials, special attention should be given to the consistency between the operational specifics of the clinical trial process and the corresponding the IFU. Regardless of whether the reagent is an clinical trail IVD reagent, a comparison reagent, or a confirmation reagent, the process of clinical trial should pay close attention to the IFU, on aspects including intended use, applicable sample type, sample anticoagulant, sample storage and processing requirements, supporting reagents used in sample processing (e.g. nucleic acid extraction reagents) and other applicable reagents, applicable devices, trial protocol, result interpretation criteria, and limitations, etc. Detailed operating procedures should be formulated according to relevant IFUs during clinical trial design, to ensure that the clinical trial is performed in strict compliance with the requirements of the IFU, and that the procedures and results of the clinical trial is capable of supporting the statements made in the declared product IFU. 21 How to establish the exclusion criteria for subjects in the design of in vitro diagnostic reagent clinical trials? In clinical trials of in vitro diagnostic reagents, reasonable criteria for subject inclusion and exclusion should be set according to the appropriate population and indications for the intended use of the product. Note: Clinical trial subjects should come from the population for which the intended use of the product is claimed (the target population) and indications, such as persons with certain symptoms, signs, physiological, pathological conditions or certain epidemiological background. Inclusion of nontarget population may introduce subject selection bias, resulting in clinical trial results that do not reflect the real situation of the product. For example, an in vitro diagnostic reagent used to assist in the diagnosis of a disease, large numbers of asymptomatic healthy subjects should not be randomly enrolled in clinical trials,Improper inclusion criteria may cause the clinical sensitivity and specificity evaluation to deviate from the true performance of the product. 22 Can you adjust positive cut-off value/reference range in IVD reagent clinical trials?The positive cutoff value/reference range of an IVD reagent should be established and validated prior to the clinical trial, and the clinical trial test results are expected to be interpreted against these adequately validated positive cutoff value/reference range. If the positive cutoff value/reference range of an IVD reagent is considered unreasonable and needs to be adjusted according to the clinical reference standard in the process of a clinical trial, the adjusted data cannot be used as clinical research data for confirming the clinical performance of the product, but can be used as research data of the positive cutoff value/reference range, after adjustment, clinical cases should be re-enrolled for clinical trials. 23How should the phrase “different sources” be interpreted in the IVD analytical performance evaluation, which states the study requirement of the use of samples from different sources?In the investigation of the analytical performances of IVDs, it is generally required that a variety of samples of an applicable population be enrolled in testing, including those from different times, places, and demographics (e.g. age, gender, ethnicity, other circumstances, etc.), i.e., selecting samples from "different sources" for evaluation. The selection of representative samples should be based on factors such as the characteristics of the product itself and its intended clinical use. 24 When applying for IVD modification registration of adding applicable instrument, if the amount of reagent or sample added on the new model instrument changes, is the submission of clinical evaluation data required?Under the circumstance where the composition, production, as well as intended use of an IVD remains unaltered, to apply for adding applicable instrument models, if there is no change in the reagent and sample addition amount on the new model or although there is change, but the ratio of reagent and sample addition amount in the final reaction system is unchanged, it is generally not necessary to submit relevant clinical evaluation data. If the proportion of reagents and samples added in the final reaction system is altered in the new instrument model, the corresponding clinical evaluation data should be concurrently submitted when applying for the modification registration. 25How to fill in the registration certificate number/record number/product code number in the “required but not included” section under the [Main Components] part of an IVD IFU manual?The “required but not included” section under the [Main Components] part of an IVD IFU should clearly list reagents that are necessary but not included in the present kit. If said reagents have already acquired registration numbers or record numbers, it is necessary to list them; if said reagents are still in the process of registration/record, it is necessary to write down “product code number and registration number: (leave blank)/record number: (leave blank)”, and for the register to fill in the blank space after registration/recording. 26Are clinical samples necessary for the preparation of corporate references?Corporate references are a key tool in product development and quality control. It is recommended that clinical samples be utilized in the preparation of corporate reference material, for exceptionally rare samples, replacement samples may be considered, e.g. pathogen cultures or cell lines, in accordance of relevant product guideline. 27 What documents are required when applying for IVD modification registration of packaging specifications?Changes in the packaging specifications of IVD reagents should describe in detail the differences in packaging before and after the change, identify all relevant potential risks based on the specific differences, and analyze and validate against these risk factors. If the reaction mechanism before and after the change of packaging (such as drug testing products), or the size of the reaction membrane strips (such as PCR amplification hybridization products) are altered, the analytical performance assessment information of the altered packages should be submitted; if the change in packaging results in significant alterations of package volume or vessel, in so far as increased risks of evaporation or loss is introduced, whether or not the product’s shelf stability, use stability, or calibration accuracy has been affected should be considered. 28 What is the test system for IVD reagents?A testing system for an IVD reagent is a combination of sample processing products, testing reagents, calibrators, controls, testing equipment, etc., that accomplishes all stages from sample processing to final result reporting. The entire testing system should be fully evaluated and approved for safety and efficacy.The product registration process of IVD reagents may not include all the other products needed to complete the test, in this scenario the supporting products need to be specified in the product IFU, to ensure that the test proceeds in accordance with all the supporting products composing the test system. For example, for nucleic acid test reagents that do not include extraction reagents, in the process of performance evaluation and clinical evaluation, it is necessary to use the matching extraction reagents claimed in the IFU. 29 Can ELISA kits be changed from "two-step" reaction model to "one-step" ones? ELISA testing methods can be sorted as “one-step” and “two-step” methods according to reaction model. The “one-step” method refers to adding the test sample and the enzyme-labeled antibody into the reaction well at the same time, “two-step” refers to adding the test sample to the well first and waiting for its reaction to end prior to the addition of enzyme-labeled antibodies. The experimental procedures differ between the two methods. The former is characterized by a shortened reaction time, but may lead to a decrease in product performance. Thus it is not recommended to switch from a “two-step” method to a “one-step” one via modification registration.
31 How to select testing samples for extractive performance study of contact lens products?The extractive performance study for contact lens products should select finished product lenses for testing purposes. Samples should be representative of factors like dye type and overall formula. With consideration of the least favorable scenario, the lens with the highest dye formulation that contains all dye types is selected. If the lens with the highest dye formulation does not contain all dye types, supplement with lenses with other dye types is necessary, with a separate process of extraction testing and validation. 32 What Research Data that should be submitted for joint prosthesis products that contain hydroxyapatite/metal composite coatings?For joint prosthesis products that contain hydroxyapatite/metal composite coatings, hydroxyapatite/metal material composition, research data on coating surface morphology (thickness, porosity, average pore intercept), composite coating mechanical properties (shear fatigue, shear strength, tensile strength, wear properties) should generally be provided. When conducting research on the mechanical properties of composite coatings, it is recommended that the failure mode of each test (e.g., failure occurs between the coating and the substrate, or between the coating and the coating, etc.) be clarified. In the absence of standardized testing methods, it is recommended that the relevant basis for determining the test methods, test parameters, and design of the testing system be provided when conducting relevant studies. For test results, sufficient supporting information should be provided to prove the clinical acceptability of the results. For this class of composite coating, the performance indicators required in the product technical requirements must specify the composite coating adhesive strength, tensile strength, coating surface quality, coating surface roughness, and thickness. 33 How to submit design verification data for single-use sterile closure clips?It is suggested to elaborate the structural design of the product, including the inner surface structure of the upper and lower arms, the size parameters, the structure of the joint, the lock, etc., in combination with the requirements of the strength, toughness and the stability of the clips in clinical use. Please describe the basis for determining the structure and the comparison with similar products already on the market. 34 In vitro diagnostic reagents add new applicable instruments, what should be described in the description of product modifications? In addition to in vitro diagnostic reagents for supporting the use of instruments, should focus on describing the similarities and differences between the proposed new instrument and the approved instrument, including the instrument's registration information, structural composition, instrument itself performance, modules and reaction procedure setting parameters and reaction system. In order to display the similarities and differences visually, it is suggested to use the way of text and illustration to describe. 35 Whether multiple single clinical trial exempt in vitro diagnostic reagents are combined into multiple joint test products and can be exempted from clinical trials? First of all, according to the Guiding Principles for the Division of Medical Device Registration Units, for the tested substances in the joint inspection project, there should be collaborative diagnostic significance for specific indications, otherwise joint inspection is not recommended. Secondly, confirm the consistency between the product and the exempt clinical catalogue products. The items to be tested should be consistent with the detection target and product description range of the exempt clinical catalogue, and the joint test should not expand the application scope of the product. In this case, a number of joint inspection products can be exempted from clinical trials. 36 Whether clinical samples are required for the preparation of corporate reference products? Corporate reference is one of the important tools for product design, development and quality control. It is recommended to give priority to clinical samples when preparing corporate reference products, and for very rare samples, consider using alternative samples, such as pathogen cultures or cell lines, it should be in accordance with the relevant product guidelines. 37 How to consider the in vitro diagnostic reagent detection limit and linear study batch and model? The detection limit and linear research of in vitro diagnostic reagents can be divided into detection limit establishment, detection limit verification, linear establishment and linear verification. The samples used for the establishment and verification of detection limits should not be duplicated, and the samples should cover all claimed or major types during the study. The applicant shall submit all applicable model registration information, structural composition, instrument performance, reaction procedure setting parameters and reaction system comparison; The representative model and other models should be basically the same in terms of working principle, detection method, reaction condition control, signal processing, etc. On the premise that there are representative models of the applicable models of the declared products, the applicant can choose the representative models to conduct 3 batches of product establishment research and 1 batch of product verification research; At the same time, 3 batches of product validation studies were conducted using other models. Applicants can also select all applicable models to conduct 3 batches of product establishment studies and 1 batch of product validation studies. The analytical performance of all applicable models should be basically the same. If different models have differences in the analytical performance of a certain test item, different models should be used to establish and verify the analytical performance of the difference. The above is the general requirements for conventional in vitro diagnostic reagents, for new products, new methods, special products or new problems in the performance evaluation, should be analyzed according to the specific situation of the application data. 38 For orthopedic implant products, if the product is directly purchased from the supplier, the applicant only carries out the steps of subpackage, sterilization, packaging, etc., and no other processing, whether the applicant can apply for registration? For orthopedic implant products, where the applicant directly purchases the finished product of the design, does not do any processing, and only carries out subsequent subpackage, sterilization and packaging, the applicant can apply for registration as a holder. The applicant shall include the relevant quality control of the products provided by the supplier into its own quality control scope. At the same time, the applicant shall submit the registration application data of the declared products according to the requirements of current regulations and normative documents, such as performance research data, biological evaluation data, product technical requirements, test report, clinical evaluation data, etc. 39If the raw materials for orthopedic and oral implant products come from two suppliers. What verification should be required?If the raw materials for orthopedic and oral implant products come from two suppliers, the applicant shall evaluate the suppliers in accordance with the requirements of the quality management system. If there are two raw material suppliers of the same raw material, and it cannot be determined that the composition, content and synthesis of the raw materials used by the two manufacturers are the same, the information provided should include the performance verification/confirmation and risk assessment (including biological assessment) of the products made of raw materials from different sources. To ensure that products made of raw materials from both sources perform consistently and meet safety and effectiveness requirements. 40 What information required by the NMPA when registering the Ultrasonic diagnostic equipment with remote maintenance and remote diagnosis functions (does not involve remote control)?Remote maintenance and remote diagnosis functions both involve remote communication. The remote maintenance function usually involves only the transmission of equipment data for routine maintenance and overhaul of equipment. The remote diagnostic function also involves the transmission of patient data and ultrasound images for remote viewing of ultrasound images or remote diagnosis. For the above functions, network security related research data should be provided, specifying the detailed purpose and the type of data involved in transmission. The corresponding functional requirements should be clearly defined in the product technical requirements, and the test report should be provided. Research data should provide verification of data transmission stability, if remote diagnosis is involved, it should also provide supporting data that data delay and image quality can meet clinical needs. It should be noted that if the patient information and image data are involved in the transfer of overseas servers, they should meet the requirements of laws and regulations related to data exit, and the applicant should fully inform the user organization of the risks, rights and responsibilities related to data exit, as well as relevant warning information and compliance, and jointly bear the responsibility of data exit declaration. 41 Precision test design of the Quantitative in vitro diagnostic reagents , should each influencing factor be evaluated separately?The precision of in vitro diagnostic reagents is affected by the operator, measuring instrument, measuring procedure, reagent lot, calibration (calibration lot, calibration cycle), run, time, location, environmental conditions and many other factors. In general, it is not necessary to evaluate each influencing factor separately, and a balanced nested design can be used to integrate all relevant factors into the design of precision tests to obtain the analysis results of repeatability, laboratory precision, laboratory precision and lot-to-lot precision. 42 When the performance index of in vitro diagnostic reagents change, how should the registrant submit the change statement?When the registrant applies to change the product performance index, the change statement shall specify the reason and purpose of the change of the product performance index, describe the specific change of the product in detail, and analyze its impact on the product performance. If the registrant claims that the product has not changed, the reason why the product has not changed but the performance index has changed should be explained in detail from the perspective of product design and development, and supporting information should be provided. 43 How to understand "continuous working time" in the performance index of active medical devices Continuous working time refers to whether the device cannot work normally due to overheat or overload in continuous working state, or the maximum working time that the battery of the internal power supply device can support. If the product itself is designed with a preset working cycle of 30 minutes, the next working cycle can be started immediately after the end of the timing, and the applicant does not give a restrictive description of the duration, cycle or interval of treatment, the product is considered to be in continuous working state and shall meet the relevant electrical safety requirements for continuous working mode. The corresponding continuous working time can be calculated according to the maximum number of work cycles that can be tolerated or supported. It should be noted that for such cases, the applicant should not directly declare in the manual that "the product can work continuously for XX hours", but should explain the single maximum working time, tolerable working cycle, cumulative working time test and calculation method together, so as to avoid the risk caused by the user's understanding deviation when using. 44 During the electromagnetic compatibility test, if the equipment accessories (consumables) have service life limits and cannot reach the duration required by the test, can you replace the same type of accessories to continue the test？During the electromagnetic compatibility test, some test projects require the equipment to work for a long time. If the accessories used cannot complete the duration required by the test, the accessories of the same model and batch can be replaced during the test to continue the test. It is necessary to consider whether the replacement of accessories in the test will affect the test itself, and it is recommended to adopt appropriate test intervals based on the life expectancy of accessories, or set appropriate test tools. |