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1 Question 1: How should the accuracy of instruments used for verifying standard materials of equipment be evaluated? Reference discussion: The En value method is generally used in normal cases. Reference materials come with standard values and uncertainties. By using these reference materials to calibrate the instrument, an inspection value can be obtained. We can then evaluate the uncertainty of this testing method, and compare it with the EN value; if it is greater than 1, the result is considered unsatisfactory ； If it’s less than 1, then it’s satisfactory. Question 2: The TTB incubation temperature for Salmonella in the device is 42±1 degrees, while that for Shigella is 41.5±1 degrees. If only 42 degrees is calibrated, can 41.5 degrees be used for Shigella? Or can the incubation temperature for Shiga be set at 42 degrees? Or do both 42 and 41.5 need to be calibrated? Reference discussion: Shiga can be used, but it must be clearly specified in the original culture records that it was done at 42 degrees. It’s best to do both options. Better. Question 3: Equipment. Should instruments be certified or calibrated? How can one determine this? Apart from checking the list of items subject to mandatory verification, how can one make a quick distinction? For instruments that require verification, is it possible to issue a calibration report? Reference discussion: If the equipment to be inspected is listed in the mandatory inspection catalog and its intended use meets the requirements for mandatory inspection, then it can be taken for inspection. Verification and calibration are determined by the laboratory; there have been previous tweets on the official account that you can check out. Items on the mandatory inspection list are subject to mandatory inspection, and the inspection is free; in fact, it is even cheaper. You have to judge the rest for yourself. In general, for devices such as pH meters, balances, etc., there is no fixed measurement value; therefore, they can be calibrated. On the other hand, devices like incubators have a fixed operating temperature, and it is best to calibrate them using those parameters. Of course, pH meters and balances can also be calibrated. It is possible to determine whether they meet our requirements by referring to the data on the calibration certificates. Generally, an inspection will yield a conclusion, while calibration merely provides objective calibration data. Calibration is usually carried out using actual samples, in accordance with relevant inspection procedures; however, these procedures may not be followed strictly, and aspects such as repeatability and bias may not be checked. In such cases, it is necessary for us to communicate with the calibration agency to clarify things. Whether instruments that require verification can issue calibration reports: For us, **verification follows specific regulations; internationally, calibration is the standard practice. Apart from those listed in the mandatory verification catalog, we do not distinguish between instruments that must be calibrated and those that must be verified. Therefore, this issue does not arise – it depends solely on how we intend to use the instruments. Question 4: For a laboratory balance, does it matter whether a desiccant is used or not when weighing, and does it have a significant impact on the measurement results? It was kept aside all along, and the room temperature and humidity there are generally sufficient to meet the requirements. For reference: Traditional mechanical balances may require desiccants, but modern electronic balances usually don’t need them; on the contrary, using desiccants could affect the results, as this would result in a dry environment inside the balance while the outside is humid, which reduces stability. As long as the environmental conditions meet the balance’s requirements, that’s sufficient. Question 5: What is the difference between function verification and calibration of equipment? Which types of equipment require function verification, and does calibration mean that function verification is no longer necessary? Reference discussion: First, the functional verification is carried out by our own laboratory, while the calibration is done by an external calibration agency. It is sufficient to keep records of the functional checks; calibration will result in a calibration certificate, and confirmation is also required. Function verification is first and foremost just one aspect of periodic inspection; not all devices require both function verification and periodic inspection. It is necessary to determine this on one’s own by considering various factors such as the frequency of device use, its impact on experimental results, and the stability of the device itself, in order to decide whether verification is needed. It isn’t necessarily required to conduct a functional check once calibration has been done; if calibration is carried out according to planned schedules, there is a fixed interval for that. Yet it might still be necessary to perform a check between two such calibration intervals Not all devices require calibration, nor do all devices need functional testing, and their scope is not comprehensive. Analyze specific devices individually. However, any verification needs to be documented; if the verification is simple, it can also be recorded in a notebook. Question 6: During the equipment review, experts pointed out that the sterilization time of the autoclave was not calibrated. However, the standard used by the local provincial metrology institute for calibrating autoclaves requires calibration only of temperature and pressure, with no requirement for time calibration. Is it necessary to calibrate the time? How should this non-conformity be addressed? Reference discussion: First, consider the equipment – autoclaves are used for sterilization. There is no specific time constraint; it is sufficient to record the start time and end time of the sterilization process, indicating the hour and minute. 8 hours and 8.5 hours make little difference, as long as the sterilization goal is achieved. Not everything said by experts is correct; we also need to make our own judgments. So, one could seek advice from expert teachers; a stopwatch can be calibrated and used to record the time and give it a try. Question 7: For the testing items in the kit that require incubation at a constant temperature, is it necessary to use an incubator? For reference in discussing whether incubation can be carried out in a heater used for detecting slow antibodies: First, it is necessary to check what the standard method specified in the kit says. If it clearly states that an incubator is required, then incubation must take place in an incubator. If there are no specific requirements, as long as we can ensure the necessary temperature conditions (accuracy and stability of temperature), we can decide on the equipment to use ourselves. Question 8: When calibrating non-standard equipment, if the calibration report does not bear the CNAS seal, can the annual surveillance audit of the laboratory’s quality management system still be passed? First of all, there is no such thing as non-standard equipment. Only the term for non-standard methods is mentioned. Reference discussion: It is guessed that non-standard equipment refers to devices that are not purchased from the market, but may be modified or developed by oneself. There are various methods for device traceability; we give priority to calibration provided by calibration institutions or verification and calibration services offered by official metrology departments. Then, one can choose to use reference materials that can certify traceability to IS units. Next are comparisons between laboratories, as well as the verification of certain standard samples. If the device was developed or modified by oneself, and there are available verification procedures or calibration specifications, then an application for verification and calibration can be submitted directly. If it can be calibrated, then the calibration certificate must bear the CNAS seal. If there are no calibration specifications or verification procedures, then surely no institution will be able to provide us with calibration and verification services. In such cases, we can see how the calibration institution approaches calibration; if traceable reference materials are used, then we can accept that approach as well. You can make a judgment based on the conditions of the laboratory. Question 9: Does the prohibition on 100% testing refer to all testing items or each individual category? For example, if one plans to test 10 parameters in drinking water, including 8 sensory and general chemical indicators, my household has the capability to conduct such tests ； The other 2 items are radiation-related indicators; my company does not have the necessary qualifications in this field. Can I subcontract all these two radiation-related tasks? Reference discussion: Yes. Generally, CNAS does not have a requirement that 100% coverage is mandatory. Generally, provincial-level CMA has specific requirements regarding subcontracting. For example, Guangzhou requires that subcontracting cannot be carried out on a 100% basis, nor can it be done by entities without the necessary qualifications. If there are no such requirements and subcontracting is possible in all cases, then subcontracting can be carried out. Generally speaking, when we say it’s not possible to cover 100% of the items, it means that the testing items for this sample cannot be covered in their entirety; this applies regardless of the field, and there is no distinction based on field. Question 10: The items related to non-compliances identified during work supervision and inspection have been compiled and submitted to the management department. However, since they are not recorded as internal non-compliance or correction records, is it necessary to record them again as internal records after the corrections are made? Reference discussion: Records must be timely; retroactive recording is not allowed. If the corrective actions have already been completed, this can be done in this way; for future corrective actions, it is sufficient to use internal forms for recording. Generally, CMA and CNAS do not require specific forms for recording such corrections, so using one’s own forms is acceptable. Question 11: There was a project for which we didn’t have any testing methods, so we found a technical paper online and used it as a guide for the testing. How should we fill in the section on the basis for testing in the report? Reference discussion: The basis for testing should be consistent with that in the commission contract. It must be determined during the contract review. If it is a short-term action done occasionally, one can discuss it with the client during the contract review; the source and title of the paper should be clearly stated according to the standards, and the report just needs to be consistent with the contract. If used over the long term, it can be turned into a custom laboratory method, which can then be validated before use. Question 12: When a method validation laboratory expands its capabilities, how should a method verification report be prepared using the gravimetric method? Reference discussion: First of all, there is no method to verify this term anymore; it is now referred to as method validation. Generally, first purchase the standard text to determine whether the resources are sufficient, then develop internal work instructions and specialized internal forms, train the staff, conduct two trials to identify difficult points and complex operations, supervise the staff, and verify the methods. Verify the detection limit, repeatability, reproducibility, and method accuracy, then assess the measurement uncertainty. Next, examine external comparison methods such as inter-laboratory comparisons, proficiency testing, and measurement audits, and conduct multiple simulation experiments to ensure a thorough mastery of these methods. Question 13: Must the signature on the original record be handwritten? Is typed text okay? Is it acceptable to have the qualified result printed as “qualified”, or is manual signing by an authorized person required? Reference discussion: It can be printed; this ensures personnel rights. Only the individual himself/herself can print their own documents; others cannot print them at will. “The “Qualified” result can be printed; the authorized signatory simply needs to verify whether this judgment is correct. Question 14: For internal personnel comparisons in quality control laboratories, how should the results of instrument comparisons be evaluated? What should a comparison report include? Reference discussion: If tolerances are specified in the standard, the tolerance method can be used; if no tolerances are given, the En value method or the T-test method can also be employed. The En value method requires the evaluation of measurement uncertainty, while the T-test method does not require measurement uncertainty, but it demands that each instrument provide 5 sets of data for analysis. The comparison report should include the personnel involved, the time taken, the methods used, the comparison data, the methods for evaluating the comparison data, the results of that evaluation, the person who conducted the evaluation, the person who approved it, and the approval date. Question 15: Quality control – Are reports required for the experiments conducted as part of the internal quality control plan? Things like personnel comparison and instrument comparison – how should the two sets of data obtained from testing be evaluated? Reference discussion: A report needs to be prepared. There is the tolerance method; if that isn’t available, the En value method and the T-test method can be used. Question 16: Quality control requires that laboratories being accredited for the first time participate in proficiency testing prior to accreditation. Do CMA laboratories also need to participate in proficiency testing before they are first accredited? No basis for CMA was found; relevant discussions: Many of the requirements for CMA are based on convention rather than having any specific basis. This suggestion should still be implemented; to verify our capabilities, we can use external methods to determine them. If the laboratory isn’t capable of doing everything, it should still do as much as it can. It is possible to participate in proficiency testing as well as inter-laboratory comparisons. At the very least, we should work on typical projects in each field.