Legal analysis: 1. Catering service units should set up permanent test holes, sampling platforms and sewage outlet signs at the exhaust outlet. 2. The sampling position of lampblack and non-methane total hydrocarbon is the same, so it should be selected in the vertical pipe section first, avoiding the flue elbow and the parts with sharp changes in cross section. The sampling position should be set at a position not less than 3 times the diameter from the downstream direction of elbow and reducing pipe and not less than 1.5 times the diameter from the upstream direction of the above components. For rectangular flue, its equivalent diameter is d=2ab/(a+b), where a and b are side lengths. 3. When the cross-sectional area of exhaust pipe is less than 1.5m2, the sampling point is the median value of dynamic pressure; If the cross-sectional area exceeds the above, the number of sampling points shall be determined according to gb/t 16157 and hj/t 397. 4. When monitoring the emission of lampblack and non-methane total hydrocarbons in catering service units, samples should be taken during the peak hours of their cooking operations (cooking, food processing or other operations that produce lampblack). The sampling frequency is three consecutive sampling times, and each sampling time is 11 minutes

Legal basis: Environmental Protection Law of the People's Republic of China

Article 41 The state promotes clean production and recycling of resources.

relevant departments in the State Council and local people's governments at all levels should take measures to promote the production and use of clean energy.

enterprises should give priority to the use of clean energy, and adopt technologies and equipment with high resource utilization rate and low pollutant discharge, as well as technologies for comprehensive utilization of wastes and harmless treatment of pollutants, so as to reduce the generation of pollutants.

article 41 pollution prevention facilities in a construction project shall be designed, constructed and put into operation simultaneously with the main project. Facilities for the prevention and control of pollution shall meet the requirements of the approved environmental impact assessment documents, and shall not be dismantled or left idle without authorization.

article 42 enterprises, institutions and other producers and operators that discharge pollutants shall take measures to prevent and control the pollution and harm to the environment caused by waste gas, waste water, waste residue, medical waste, dust, malodorous gas, radioactive substances, noise, vibration, light radiation and electromagnetic radiation.

enterprises and institutions that discharge pollutants shall establish a responsibility system for environmental protection, and clarify the responsibilities of the person in charge of the unit and relevant personnel.

key pollutant discharge units shall install and use monitoring equipment in accordance with relevant state regulations and monitoring specifications, ensure the normal operation of monitoring equipment, and keep original monitoring records.

it is strictly prohibited to illegally discharge pollutants by means of concealed pipes, seepage wells, seepage pits, perfusion or tampering with or forging monitoring data, or by means of abnormal operation of pollution prevention facilities to evade supervision.