| 摘要 |
<p>PURPOSE:To detect a fine and very thin floating metal powder in a wide range of an oil tank by a method wherein a pair of electrodes using a thin film metal is made to interlock on an insulation substrate in a comb as opposed to each other to measure a pulse voltage generated by the metal powder. CONSTITUTION:Metal for electrodes is deposited on a highly insulating substrate 6 and formed in a comb by etching or the like. A counter interval (t) of electrodes 1 and 2 ranges 1-50mum and the width of the electrodes 1 and 2 ranges 3t-8t. Metal composing the electrodes 1 and 2 employs Ta, W, Pt, Au or the like that would not make an insulating portion or a semiconductor by oxidation. In the detection, a sensor is immersed into a lubricant and a voltage of 30-50V is applied between the electrodes 1 and 2. With the existence of metal abrasives, a pulse voltage is generated in the electrodes 1 and 2 to be detected with a detector 5. The level of the height of the pulse voltage is proportional to the squaring of a particle size and the frequency of the pulse is proportional to a particle density. Thus, the particle size and density of the metal abrasives can be learned in the lubricant by detecting the pulse voltage and the frequency.</p> |
