Comus RI series of glass reed switches are miniature dry contact magnetic switches that are hermetically sealed in a gas filled glass sleeve. A dry-reed switch can be defined as an assembly that contains two ferromagnetic NiFe contact blades hermetically sealed in a glass envelope and filled with an inert gas. The inert gas atmosphere protects the contact resistance of the reed switch, which is one of its most important electrical performance characteristics. The inert atmosphere is maintained by the integrity of the critical glass-to-metal seal of the switch. This seal is defined as a “residual stress seal,” which means that the seal is sensitive to handling.

When properly made, this seal will maintain the inert gas atmosphere of the reed switch for a maximum of thirty (30) years. However, improper handling of the switch and the application of the excessive mechanical force of the switch leads, for example during assembly on prints, may result in a loss of the seal hermeticity. If damage is caused, it might be immediately visible as a glass crack in the seal area with or without the evidence of chipped glass particles. Or a latent defect may be created that will deteriorate the seal hermeticity over time due to the residual stress of the seal being altered through the improper application of a mechanical force. Once the seal integrity is compromised, atmosphere oxygen and other contaminants will degrade the contact resistance and the life expectancy of the switch will be severely impacted.

Reed Switch Handling Instructions

Reed Switch Cutting and Bending Instructions