Research on the influnce of impurity atmosphere to arc burning between contacts of sealed relay

Some certain protective gases are often filled in the sealed relay in order to improve the reliability and life of relay contacts. However, it is inevitable for the existence of impurity atmosphere even in the good sealed relay. What influence on the arc will these impurity atmospheres do? Aimed at several popular impurity atmospheres, this paper began with building the microscope model of the arc and did calculations on microscope parameters of the arc: (1) pure nitrogen; (2) nitrogen with little metal vapor; (3) nitrogen with little oxygen; (4) nitrogen with little water vapor. Then it did arc spectrum experiment by putting the relay contacts in a special sealed pot filled with above atmospheres. Species and light intensities info are gained. The results of experiment is basically uniform with the results of theory calculation and shows that the metal material of contacts can do some influence on arc as well as the impurity gas in pure nitrogen will lead to more chemical reactions happen and bring out many particles. These factors all strengthen the conductivity of arc and may aggravate the contact erosion.