After each experiment, all participants in the experimental research should sign the original records by the experimenter and the person in charge of the experiment. Many places in the original records involve signatures, so we should correctly understand the seriousness of signatures. All signatures must be completed by myself and cannot be signed on behalf of others.

2. Experimental methods

CNAS requires laboratories to use appropriate methods and procedures for all tests.

The laboratory is facing the product. Different products implement different standards and use different detection methods. For products with clear implementation standards, just choose the detection method in the standard. In practical work, we will encounter a large number of non-standard products, especially in entrusted inspection, we need to communicate with customers and adopt methods that meet customer needs and are suitable for inspection.

When the customer does not specify the method to be used, the laboratory should choose the appropriate detection method from the methods published in international, regional, national and industry standards, or methods published by well-known technical institutions or related scientific books and periodicals, or methods specified by equipment manufacturers. The testing methods developed or adopted by the laboratory can also be used if the expected purpose can be achieved and confirmed.

3. Sample information

After receiving the sample, don't rush to test it. First, check whether there are any defects in the sample state that affect the normal detection. For some packaged samples, if the defects cannot be directly observed, the inspection should be terminated immediately when the package is opened, and the samples should be properly handled and communicated with customers in time. Even if there are no defects, the sample state should be properly described in the original records.

4. Record modification

The original records shall not be deleted, modified or increased or decreased at will. If revision is needed, a diagonal line should be drawn at the revision place, and it cannot be completely blacked out, so as to ensure that the records before revision can be identified and signed by the reviser, indicating the revision time and reason.

5. Standard solution

Commonly used standard solutions include titration solution, standard pH buffer solution, standard colorimetric solution, standard lead solution and standard arsenic solution. When using these standard solutions, the process of preparation and calibration should be recorded in the original records, or the source should be indicated, and the preparation and calibration records should be recorded in another record book.

6, use and recipients registration

During the experiment, we should register the use of the instrument, and the original records should correspond to the use registration. The collection and registration of some special reagents (poison, hemp, essence and release) should correspond to the original experimental records, and the collection records of reference substances and reference medicinal materials should correspond to the original experimental records.