A High-Impedance, Nanosecond Rise Time Probe for Measuring High-Voltage Impulses

Normal voltage dividers for high-voltage impulses are connected to the test object by an open air line which, when considered as part of the measuring system, gives an initially low input impedance to that measuring system due to the characteristic impedance of the line. This initially low impedance has been over- come by building a divider which can be used as an attenuator probe connected directly to the point on the test object at which the voltage is to be measured. By having the probe at a distance from the ground plane, the input capacitance can be kept low, thus allowing the probe to have a shorter rise time. Examples of results are given.