US Patent 9703264 Timing device

The timing device is a lifetime monitor for indicating when the usable lifetime of a product has ended or for indicating the timing for regular usage of a product. The timing device has a timing initiator, a power supply in the form of a membrane zinc air battery and a visual or audible indicator. The timing initiator is a tear-off air blocking membrane which lets in air when the tear off film is removed. The timing device is capable of indicating a predetermined passage of time which is substantially independent of ambient temperature.