Some Measurement Techniques for Characterizing Sealed Reed Contact Performance

The sealed magnetic reed contact offers many possibilities for improved switching performance. As its use is extended into new fields, particularly the area of miniaturization, new forms of tests are needed to characterize its behavior. Some measuring methods pertinent to such characterization are described in this paper. In the field of contact resistance, procedures are indicated for correlating resistance stability with the degree of magnetization applied to a coil surrounding the contact. Also, a procedure for applying magnetic measurements to the sealed units is described which permits accurate estimation of the actual contact forces. A new technique for characterizing the energy-handling ability of the contact is outlined. The method applies the variable stress technique used in many strength of materials studies and more recently in semiconductor device evaluation. As shown by examples, it appears to offer considerable promise for comparing designs, determining reliability, making extended estimates beyond the available data, and identifying and isolating various physical mechanisms that control performance.