Suction belt conveyor of a rod-forming machine of the tobacco processing industry for conveying materials, in particular tobacco, a rod-forming machine of the tobacco processing industry and use of the rod-forming machine and a method for measuring material properties of a material rod of the tobacco processing industry. The suction belt conveyor includes at least one rod guiding channel, which is open at the bottom and which is delimited by two lateral channel sides and a suction belt along a conveying path. At least one electromagnetic measuring device is integrated in the channel sides of the suction belt conveyor at at least one position along the conveying path in order to determine properties of the conveyed material.