IMPROVED TRANSDUCER DESIGN FOR MACHINE WEAR DEBRIS MONITORING

In recent years several systems have been reported which use coils pla ced close to the lubricant flow in a machine to monitor the presence o f metallic wear debris. Operation is based on changes in coil inductan ce caused by metallic debris the coil. Unfortunately, any air bubbles or water droplets in the lubricant stream will modify the stray capaci tance of the coil, leading to false indications. The purpose of the Le tter is to describe a method of coil construction that overcomes the p roblem of bubbles being detected as metallic debris.