I wonder why they need silver at such high purity. Wouldn't gold be a better alternative?
Nope, remember SIlver has the Highest Conductivity. So whatever the application is they must need absolute best conductivity they can achieve. Impurities would also greatly affect the conductivity at very small levels. I imagine for something like a magnetic sensor (magnetism then induces the current) that the absolute best conductivity would result in the Best sensor / most sensitivity to sensing whatever they are trying to find.
Think of impurities as that Slow Ass driver in the Left lane. Just one stupid Copper ion could back up the whole road.
