English to Spanish Tech/Engineering Transport / Transportation / Shipping

Hello,

The term appears in the maintenance description for slab tracks, the text specifically talks about inspections of the track rails. I don't really know how to translate "rail surface recording car". Does anyone have an idea?

Context:

Defect Indication Possibilities
Simple optical inspections
Ultrasonic inspections
Inspections with a rail surface recording car
Inspections with special rail measurement devices

Thank you very much in advance!