This charge transfer is due to the mechanical release or closure of the contacts, the contact-to-coil capacitance, and the stray capacitance between signal and relay drive lines.

A basic approach to high speed measurements is to minimize stray shunting capacitance through careful mechanical design of the picoammeter.

It is the result of stray capacitance, mutual inductance, and leakage resistance between channels and is generally given in decibels at a specific frequency.