Inductive spikes induced on power lines can be minimized by using varistors
or diodes across switched relay and solenoid coils. Both ends of coaxial cables carrying RF should be grounded to minimize the radiation of magnetic field interference.
As we have seen above, there are many methods for reducing the pick-up of coherent interference in low level analog signal conditioning systems.
Lead dress is important—separate low level leads from wires carrying high currents and voltages. Low level leads should be twisted and routed near the grounded case.
If twinax (twisted and shielded) cable is used, it should be grounded at one end only, and insulated.
Alternate grounds and signal leads on ribbon cables and in connectors must be ensured.
High impedance, low level leads should be kept as short as possible—this is especially true in wiring op-amps.
The summing junction should never have an exposed lead of more than 1.3 cm connecting components to it.