What are the precautions for the use of standard substances:

1. Follow the instructions for use and storage.

2, the validity period on the certificate should be observed, and the certified reference material/standard sample should not be used beyond the validity period.

3. For certified standard materials/standard samples that can be used multiple times, ensure the tightness of their packaging and storage methods meet the requirements. In some cases, it is necessary to repackage the remaining parts, otherwise the characteristic values given may not be valid, making the certified reference material/reference sample unusable or unreliable. The user should follow the instructions provided by the producer in this regard.

4. Sampling should be done according to the minimum sampling quantity given. Less than the minimum sample size is not representative.

5, for the certified reference material/standard sample that can be used several times, it should be mixed again before use. Otherwise, in the long run, the remaining certified reference material/reference sample will no longer be representative of the produced and valued package lot, and the values and uncertainties given on the certificate will no longer be valid.

6, the standard material marked "this standard material after opening please use it all at once", can not be poured into other packaging for multiple use.

What are the uses of the standard material:

1. It can be used as a sample for precision evaluation of the method. More uniform than lab samples.

2. Evaluation of bias (estimates of system measurement errors). The bias estimates obtained from the certified reference material/reference sample used for calibration can be used directly for calibration. For tests, bias correction is more complex, and the properties of certified reference materials/standard samples can hardly fully reflect the properties of everyday samples. In many cases, improvements are recommended to reduce or eliminate bias, rather than trying to correct it. Some standards provide guidelines for acceptable bias.

3, equipment calibration, establish calibration curve.

4. Assign value to the sample.

5. Agree on the scale. For example, the Mohs' scale used to measure hardness in geological experiments is based on ten minerals assigned to ten hardness levels, and each of the harder minerals can scratch the less hard minerals. pH scale: Since absolute single-ion activity cannot be measured experimentally, pH is considered a loose physical quantity. In order to make the pH being measured as meaningful as possible, a convention pH scale is adopted, which is defined by the standard solution to which the pH value is assigned. The pH values of these solutions are calculated by measuring the electromotive force of a non-migrating hydrogen-silver/silver chloride cell and using the given calculation method according to convention.

6. Quality control.

7, check the expired standard.

The above content is about the use of standard substances and what the use of standard substances all introduced, now the rapid development of China's standard material industry, thanks to the rapid development of China's measurement instruments, so that China's standard material authority to further improve, international recognition in the world to provide reference. If you want to know more about standard substances, please pay attention to us.