The design of infrared methane monitor based on the infrared abaorbtion sepectra principle is introduced.The pyroelectric infrared sensor is used as the sensing element

the C8051F040 is used as the intelligent control unit

the accurate measuring of methane volume fraction is actualized by the infrared methane monitor.The structural design of the sample cell

the amplified circuit design of the week signal and the design of the data acquisition are introduced in detail.It shows through analysing experimental data that the monitor has the performance of high accuracy

good stability and low consumed power etc.It meets the demand of utility.