The order of developing instruments for process control proposed in [3] was confirmed on a concrete example. The ITP-1 instrument allows controlling the thickness of a fluoroplastic coating on a polyimide film directly in process equipment by a contactless method of measurement. The technical solutions for controlling the thickness of film and fibre materials when the object measured exhibits transverse mechanical oscillations are reported. A method is proposed for checking the ITP-1 instrument using a calculation equation. A possible area of application of these process solutions is indicated.