.50 Lpm Laser Particle Counting Sensor Development

The particle counter based on the principle of light scattering has been widely used in clean room test, airborne particle monitor and particle research, because of its fast, high precision, good repetition and suitable for on-line measurement characteristics. China relatively backward in this area, most of the previous product use the photomultiplier as the photo detector, the maximum sample flow rate only 28.3L/min and can only detect particles bigger than 0.3 micron. As of the upgrade of standard and the development of modern industry, the particle counter whose sample flow rate is 28.3L/min can not meet the needs of modern industry. So it's necessary to develop a particle counter with higher sample flow rate.This article carefully analysis the factors that affect the counter's performance. And than raised the method how to improve the sample flow rate in the context of doesn't reduce the counter's other features. Than developed a laser particle counter which sample flow rate is 50L/min, detection sensitivity is 0.3 micron and photo detector is photodiode based on the laser particle counter whose sample flow is 28.3L/min, detection sensitivity is 0.3 micron.Finally compared this counter with LasairⅢairborne particle counter, the result show this counter has met the requirement of ISO 21501 and can keep up with LasairⅢ. Now this counter has been used by many Suzhou companies.The result of this article played a certain role in Chinese development of laser particle counter, and provides a widely available instrument for clean room testing.