Tests were conducted on several diverter strip designs to obtain comparative performance data.
 

LDS10-01-05 diverters had breakdowns at greater than 235 kV. Breakdowns of 65 to 70 kV were obtained for the LDS10-01-34 diverter strips. Withstands at 160 kV were obtained for the LDS10-01-48 diverter strips. Breakdowns of 75 and 105 kV, with one withstand at 160 kV, were obtained for the LDS10-01-39 diverter strips.

LDS10-01-64 had breakdowns of 58 to 70 kV for small round buttons, and breakdowns of 27 to 60 kV for both the ovals and the large round buttons.
 

Tests were conducted by applying fast rising impulse voltages across a one- meter length of the diverter strip. The diverter strips were attached to a 3.5 inch diameter PVC pipe for testing. The voltage to breakdown and the current conducted after breakdown was monitored. The impulse voltage was delivered from a 5-stage Marx circuit (0.05 :F) and a 2.5 nF load capacitor. A 100 ohm resistor was connected between the load capacitor and the diverter strip to control discharge current. The applied voltage was monitored on the resistive voltage divider and the current was monitored with a pulse current transformer. The measurements were displayed and recorded on a digital storage oscilloscope (DSO). All reported data was taken form the DSO..2

The circuit supplied a nominal 350 kV/µs voltage rate-of-rise. Typical applied voltage and current oscillograms are given in Figure 1.

All measurements were made using equipment calibrated in accordance with the requirements of MIL-STD-45662A. A list of test equipment is given in Table 1, which includes calibration data where appropriate.
 

The segmented strip breakdown voltage test results are given in Table 2.

LDS10-01-05 diverters had breakdown levels greater than 235 kV.

Tests on the LDS10-01-34 diverters had breakdowns of 65 to 70 kV. The LDS10-01-48 diverters had breakdown levels greater than 160 kV. The LDS10-01-39 diverters had breakdowns of 75 and 105 kV with one withstand at 160 kV.

The LDS10-01-64 group had no withstands with breakdowns ranging from 25 to 70 kV. The .060 dia. (SR) buttons had the highest breakdowns, ranging from 58 to 71 kV. Both the 0.125 dia. (LR) buttons and the ovals (OV) had very similar breakdown ranges of 27 to 60 kV.

The LDS10-01-64 group data reflects the application of several tests to the same sample. If only the first two tests on each sample are considered, the breakdown range drops considerably for the (LR) and (OV) segment diverters. Both are in the range of 22 to 30 kV.