Detonating cord and continuity verification system
 A continuity checking system for detonating cord having four principle parts. The detonating cord has a fiber optic cord associated therewith to run from the blasting cap to a remote primer; a light return device is installed at the primer; a disposable testing head is installed at the end of the detonating cord adjacent the blasting cap; and a testing device is positioned a safe distance away from the disposable testing head. The testing head utilizes an LED with means for illuminating the end of the fiber optic cord, and a light sensitive device with means for sensing return light from the fiber optic cord. An electrical input signal, and an electrical output signal from the disposable testing head is communicated by electrical wires to the remote testing device. The remote testing device functions to test for a signal from the light sensitive device before supplying an input signal to the LED following which a time delay is initiated before the output signal from the light sensitive device is used to indicate continuity. 
Research Energy of Ohio, Inc.
C G F
C06C G01B F42C
inventional inventional inventional
Robert A. Richard E. James D.
Ziemke Walker Heckelman