Relays switching at minimal loads require clean contacts.
Not only have relay designs changed, but also applications are more diverse. In modern electronics, signal levels decrease while system impedance increases. Therefore, relay contacts are operated at low or dry circuit levels with small currents. No arcing occurs to clean the contacts and due to circuit requirements, load levels of varying magnitude are applied to the same relay. One contact system is used to switch the load; the other is used for monitoring purposes.