Particle detecting method and storage medium storing program for implementing the method

A computer-readable storage medium storing a particle detecting program for causing a computer to execute a particle detecting method of detecting particles carried by a gas stream, the program comprising:

• a scattered light intensity-measuring module for measuring intensity of scattered light generated when a light emitted into the gas stream is scattered by a particle, using a light receiving unit at predetermined time intervals;
• a maximum intensity measuring timing-selecting module for dividing a measuring time period for measuring the scattered light intensity into measurement periods each defined as a predetermined time period, and selecting a measured time point in each measurement period at which a maximum value of the scattered light intensity measured is measured;
• and
• a passed particle counting module counting a number of particles having passed by in front of the light receiving unit, based on the measured time point selected in each measurement period.