Relay test equipment allows the engineer to inject current into the relay and measure the resistance, voltage and current. A basic relay test looks at the resistance of the relay to check for shorts. The voltage and current transmitted and required by the relay can also be checked. Rent relay test sets online from brands such as Omicron, Chauvin Arnoux, Ponovo, Megger, EuroSMC, Kocos and T&R Test Equipment.