Weor, 70 (1981) 219 - 226 @ Elsevier Sequoia S.A., Lausanne - Printed in The Netherlands 219 SURFACE CONDITION MONITORING OF GRINDING WHEELS BY PNEUMATIC BACK-PRESSURE MEASUREMENT J. FAZLUR RAHMAN and V. RADHAKRISHNAN ~e~Qr~rne~~ of mechanical engineering, Indian Insf~~ate of Technology, Madras 600 036 {Zndia) (Received November 5, 1980) Summary A practical method for assessing the condition of wheel surfaces by determining the air flow around the wheel with back-pressure measurements using a pneumatic gauge is described. Different wheel surface profiles were compared and the change in wheel topography from a freshly dressed condi- tion to a glazed condition was ascertained from the back-pressure measure- ment. This simple and rapid method is suitable for determining when wheel redressing is necessary to achieve better performance. 1. Introduction Surface finish and dimensional accuracy are the two important factors which have to be controlled to ensure good quality in precision grinding. In- process measurements have been developed to control the workpiece size during processing, but monito~ng of surface roughness has not yet been perfected. The metal removal rate, grinding time and ground volume have a signifi- cant effect on the work surface roughness. During grinding, the topography of the wheel surface changes because of the wear and fracture of the abrasive grams, resulting in a variation in the work surface roughness. The work surface roughness may be predicted to a certain extent from the topography of the wheel surface and the dynamic behaviour of the wheel during grinding. Thus a considerable amount of research has been devoted to the investigation of the cutting surface of the grinding wheel [ 1, 2 ] . Al- though several approaches have been tried, the determination of the exact wheel topography for the prediction of the ground finish still appears to be a tedious and time-consuming job. In this paper we describe a simple technique for the assessment of grinding wheel topography based on the dynamic pressure and air velocity around a rotating grinding wheel.