A system for mounting a sensor on a construction machine is described. The system includes a sensor having a bottom interface and a base for mounting the sensor on a construction machine. The base includes a top interface for rotatably interlocking with the bottom interface of the sensor. The rotatably interlocking of the base with the bottom interface of the sensor causes one or more terminals of the bottom interface of the sensor to communicatively couple to corresponding terminals of the top interface of the base.

A system for mounting a sensor on a construction machine is described. The system includes a sensor having a bottom interface and a base for mounting the sensor on a construction machine. The base includes a top interface for rotatably interlocking with the bottom interface of the sensor. The rotatably interlocking of the base with the bottom interface of the sensor causes one or more terminals of the bottom interface of the sensor to communicatively couple to corresponding terminals of the top interface of the base.

An electromagnetic relay unit includes an electromagnetic relay; a socket that connects the electromagnetic relay to a mount board; a first terminal provided at the electromagnetic relay and including a first plate portion; and a second terminal provided at the socket to be connectable with the first terminal, and including a second plate portion, the first plate portion and the second plate portion being provided to face with each other when the electromagnetic relay and the socket are connected with each other, at least one of the first plate portion and the second plate portion including a projection that contacts the other of the first plate portion and the second plate portion.