Micro-ohm shunts for precise recording of short-circuit currents

A new design of the tubular shunt is presented which offers a reduction of the response time up to 10 times without changing the volume of the resistive material and preserving a regularly shaped response. A new formula is derived which gives the necessary data for calculating the improved shunt. Another possible design option is also presented which gives a shunt with zero response time but then the response curve indicates a larger overshoot. A simple mechanical design is presented, particularly suitable for heavy current shunts in the microohm range. Two such shunts were built for precise recording of steep front, short-circuit currents with a large asymmetry. They were designed according to the new formula and experimentally examined with a step impulse current. The measured response time of these shunts are in agreement with the calculated data.