There are many concerns about LNG in its production and use. When delivering natural gas to end users such as gas power plants and energy companies that supply gas to home heating users, it is necessary to understand the composition of the natural gas, determine the calorific value of the natural gas, and ensure that it meets the legal natural gas composition standards. Local real-time analysis can help quickly determine whether LNG is doped with nitrogen and other low-temperature gases. In order to adjust the composition of natural gas to comply with legal standards, it can also be used in mixing stations where nitrogen is added to high calorific value natural gas to convert it into low calorific value natural gas.