High-voltage Single-ended Probes - High-voltage single-ended probes are commonly used for measuring below 40 kV referenced to ground signal. However, certain single-ended probe designs are intended for instruments with isolated or floating inputs, for measurements not referenced to ground. Users should select probes with lower input capacitance specifications (< 4 pF) to minimize the probe's load on the circuit, as lower capacitance probes can provide higher input impedance at higher frequencies.