This standard establishes guidelines related to various aspects of sampling of processed natural gas. Unless otherwise stated, all pressures in this standard are given in gauge pressure, which can be up to 15 MPa, compressed natural gas (CNG) pressure can be up to 30 MPa, under the premise of ensuring the safety of the sampling system, this standard can be used. This standard involves point sampling, combined sampling (cumulative sampling) and continuous sampling system. This standard considers oxygen, hydrogen sulfide, air, nitrogen, carbon dioxide, etc. components, this standard does not cover the sampling of liquid or multiphase fluids, if traces of liquids such as glycol and compressor oil are present, they are considered interfering impurities and are not part of the sampled gas and should be removed to protect Sampling and analysis equipment shall not be polluted. This standard applies to transfer metering systems and distribution metering systems. This standard applies to those situations where sampling is not described as an analysis step. This standard focuses on describing sampling systems and steps. For those using these The analysis of samples obtained by the system and steps can be used in many aspects, including calculating and determining the calorific value of the airflow, identifying the pollutants in the airflow, and judging whether the airflow meets the technical indicators stipulated in the contract based on the composition.