Apparatus and method for measuring the concentration of large particles in a gas

摘要

The invention provides apparatus and method for measuring the concentration of large particles in a gas which may also contain small particles. The apparatus comprises a triboelectric charging means which effects triboelectric charging of the large particles in the gas, and charge measuring means for measuring charges on the particles in the gas after it has passed the triboelectric charging means. The triboelectric charging means can be a curved section of an air intake duct or the compressor of a turbocharger. The apparatus enables the operation of an engine or other air consuming device to be interrupted when the concentration of large particles in the incoming air is sufficient to damage the engine, but avoids unnecessary shutdowns due to the presence of small particles, e.g. smoke particles, which are too small to damage the engine or other device.