In the prior art, it was necessary to adjust the time required for a measurement operation for moving a
welding tip to a prescribed measurement location in order to measure a wear amount. This device 80 comprises: a measurement operation
execution unit 70 that controls a mobile
machine 58 so as to execute a measurement operation for moving a
welding tip in a first direction to a measurement location; a
location data acquisition unit 72 that acquires the location of the mobile
machine 58 when the measurement operation has been executed; and a measurement
initiation location determination unit 74 that determines, as a measurement
initiation location, a location for the mobile
machine 58 at which the
welding tip is arranged a prescribed distance apart from a first location in a second direction, which is opposite of the first direction, on the basis of the first location which is acquired during a first measurement operation. During a second measurement operation following the first measurement operation, the measurement operation
execution unit 70 controls the mobile machine 58 so as to position the mobile machine 58 at the measurement
initiation location and then move the welding tip in the first direction.