The grouping test method at four constant stress levels was applied for short life span areas while the stress up and down test method were used for long life span areas.

By comparing the advantage and disadvantage of ramp current with other methods, ramp current method and up-and-down method are used to test sensitivity of bridge-wire Electrical Initiating Device.

K... the grouping test method at four classes of constant stress levels was applied for short life-span areas while the stress up-and-down test method was used for long life-span areas.