In order to realize the value transfer, the national metrology department often needs to clarify the measurement standards at all levels and the accuracy differences between measurement standards and working measuring instruments, specify the names, ranges, accuracy and verification methods of benchmarks, standards and working measuring instruments, and write technical documents in the form of words combined with charts. A verification system so specified is called a verification system.

The value transfer must pass the verification. The so-called verification is to evaluate whether the measuring performance of measuring instruments is qualified. The telecommunication departments that use telecommunication measuring instruments shall regularly send the measuring instruments to the higher-level telecommunication measuring departments for verification as required; Or send the S-high measurement standard of this department to the higher measurement department for verification, and then periodically verify the measuring instruments with the verified measurement standard to ensure that the value of this department is consistent with the national standard.

In the absence of higher precision measurement standards, we can compare the values between measuring instruments of the same precision level to achieve relative unity of values. This measurement method is called comparison.

In order to ensure the smooth transmission of telecom values, a telecom metering network is set up in the telecom system, which is composed of ministerial metering stations and regional, provincial and municipal metering stations, each with its own corresponding level of metering standards. Through the gradual transmission of values, the accuracy of working metering instruments in various telecom departments is ensured.

Although the measurement value transfer process can evaluate the measurement performance of the measured measurement standard, due to the different environmental conditions and the degree of thermal training, it sometimes cannot reflect the actual measurement performance achieved when using this standard to verify the lower-level measuring instruments. Therefore, measurement assurance plan (MAP) is implemented abroad. In this scheme, the national metrology department first verifies the special transfer standard, and then sends it to the local metrology department for verification. The transfer standard returns to the national metrology department before verification, and then analyzes and compares its own verification data with the verification data of the local metrology department, and at the same time issues a verification report. The total uncertainty of the verification process given by MAP reflects random error and systematic error.