Monitoring device for coating substrate with paste - using capacitive sensor in HF resonant circuit whose frequency change is measured as sensor moves parallel to surface

摘要

The arrangement for monitoring substrate coatings contains a capacitive sensor arranged perpendicular and close to butnot in contact with the coating surface. The sensor is connected into a high freq. resonant circuit whose freq. change is measured as the sensor is moved parallel to the surface. The sensor (10) contains at least one probe (7) which represents the open end of a quarter-wave gudie forming part of the high freq. resonant circuit. USE/ADVANTAGE - For monitoring coatings in the liq. to paste range. Efficiency of capacitive monitoring device is improved w.r.t. conventional ones.