Rbd. Knight et P. Martin, A HIGH-VOLTAGE DIVIDER HAVING AN UNCERTAINTY OF 5-PPM AT 100 KV, IEEE transactions on instrumentation and measurement, 42(2), 1993, pp. 568-570
A high voltage dc divider has been designed and constructed for use as
a standard at 100 kV. A self-shielding arrangement controls leakages
due to corona currents. A modular version having three 50 kV sections,
which can be used singly or in any combination, is also available and
used in the calibration process. The design can be extended and versi
ons have been made elsewhere for use at voltages up to 1 MV. The divid
er ratio is first established at a low voltage. Influences which may c
hange the ratio at the working voltage are identified and limits to th
eir effects are estimated. A high-resolution isolated current measurin
g instrument has been developed which makes it possible to compare the
currents entering and leaving the divider resistor chain at the high
and low potential ends. This provides a resolution better than 1 ppm o
n a current of 100 muA. In use, the divider ratio is known to an uncer
tainty of 5 ppm (1sigma).