Fast Measurements with Modified HVD Series of High Voltage Dividers

HVD series of precision high voltage dividers manufactured by Spellman are specified for DC measurements only. As such, they possess very high input impedance (1
$\mathrm{G}\Omega$
and higher) and are corona-free. We modified 100-kV and 200-kV models for time-domain measurements, extending the range of HVD100 to 140 kV. These models are dubbed HVD100C, HVD140C, and HVD200C (“C” stands for “compensated”). The last two models' corona suppression electrodes have also been modified, and E-field analysis is described showing that the field is below corona inception. Typical usable risetime is 2
${\mu} \mathrm{s}$
for 100-kV and 140-kV models, and 10
$\mu \mathrm{s}$
for the 200-kV model. Settling time to 0.2 % is less than 2 ms for 100-kV and 140-kV models. HVDs are calibrated for fast response both at low and high voltage by step response method; calibration results are provided. The modified, compensated, versions retain the same NIST-traceable DC accuracy as their original DC counterparts. Compensated HVDs are useful for laboratory and manufacturing practices when fast HV time domain measurements are necessary in combination with high dc accuracy and high input impedance.