Source: Jim Lux, 1998
Symmetrical Sphere Gaps
This data applies to gaps where neither sphere is grounded, or, where the gap is so far from the surroundings that the fields relative to ground have no influence.
All voltages in kiloVolts with air at 20deg C, 760 torr, either polarity impulse, AC, DC
spacings <0.5D Accuracy +/- 3% ; spacings >=0.5D accuracy +/- 5% (shown in italics)
|
Sphere Diameter (cm) |
|
|
|
|
|
|
|
gap (cm) |
5 |
10 |
15 |
25 |
50 |
100 |
150 |
200 |
0.5 |
17.5 |
16.9 |
16.5 |
|
|
|
|
|
1 |
32.2 |
31.6 |
31.3 |
31 |
|
|
|
|
1.5 |
46.1 |
45.8 |
45.5 |
45 |
|
|
|
|
2 |
58.3 |
59.3 |
59.2 |
59 |
|
|
|
|
2.5 |
69.4 |
72.4 |
72.9 |
73 |
|
|
|
|
3 |
79.3 |
84.9 |
85.8 |
86 |
|
|
|
|
4 |
|
107 |
111 |
113 |
112 |
|
|
|
5 |
|
128 |
134 |
138 |
138 |
137 |
137 |
137 |
8 |
|
177 |
194 |
207 |
214 |
|
|
|
10 |
|
|
|
248 |
263 |
266 |
267 |
267 |
12 |
|
|
|
286 |
309 |
|
|
|
14 |
|
|
|
320 |
353 |
|
|
|
16 |
|
|
|
352 |
394 |
|
|
|
18 |
|
|
|
|
452 |
|
|
|
20 |
|
|
|
|
495 |
504 |
511 |
511 |
25 |
|
|
|
|
558 |
613 |
628 |
632 |
30 |
|
|
|
|
|
744 |
741 |
746 |
35 |
|
|
|
|
|
812 |
848 |
860 |
40 |
|
|
|
|
|
902 |
950 |
972 |
50 |
|
|
|
|
|
1070 |
1140 |
1180 |
60 |
|
|
|
|
|
1210 |
1320 |
1380 |
70 |
|
|
|
|
|
|
1490 |
1560 |
80 |
|
|
|
|
|
|
1640 |
1730 |
90 |
|
|
|
|
|
|
|
1900 |
100 |
|
|
|
|
|
|
|
2050 |
|