Abstract: A process for mapping the path of an electric arc through a sample of resive material whereby the magnetic field propagated by the arc is recorded on a sleeve of magnetic sensitive material which surrounds the sample, with the intensity of the recorded field at different points on the sleeve indicating the path of the arc.

Abstract: Light shown through a space containing smoke or an aerosol is detected from everal paths through the space. The light may be gathered from physically separated optical fibers feeding a common photodetector, or several physically separated, series-connected photodetectors may be used. The total amount of light reaching the photodetector(s) is directly related to the average density of the smoke or aerosol.

Abstract: A circuit for determining the fire no-fire characteristics of electroexplve devices involves the application of an incrementally adjustable current level automatically to successive electroexplosive devices. The initial predetermined current level is applied to the first electroexplosive device under test. The current level applied to the next and succeeding electroexplosive devices is increased or decreased automatically by a predetermined amount, depending on whether the previous unit functioned or not. This method results in a mean firing current level being obtained with less chance for error and less operator involvement than required by presently established procedures.

Abstract: A ramp current method of sensitivity testing allows a dynamic record to be btained of the current, voltage, and energy, as well as resistance and instantaneous power necessary to fire electroexplosive devices. This method is most valuable in that useful information is gained from each firing and thus only minimum sampling is utilized. The ramp method also allows a defective item to be detected rather than recorded as a less sensitive device and therefore as an erroneous data point, contributing to more accurate firing data.