Particle counting method
First Claim
1. A method of particle counting, the method comprising:
- irradiating a sample gas with a light;
detecting a scattered light from a particle included in the sample gas by a photoelectric conversion device;
counting a number of the particles of every particle size division by an output voltage wave pattern of the photoelectric conversion device; and
calculating, with a Digital Signal Processor (DSP), a time difference (Ta−
T1) with a point (T1) of a peak of output voltage wave pattern and a point (Ta) of a falling detection threshold (A), when the time difference (Ta−
T1) exceeds a counting cancellation time (B), the output voltage wave pattern is not counted as a particle.
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Abstract
A particle counting method that can count the number of the particles precisely. The method discriminates a wave pattern of the scattered light from a normal particle (subject of the counting) and a wave pattern of the light scattered by the agitation such as a floating particle, a radiation or changes in the intensity of the light. In one embodiment, a method for counting particles is disclosed which irradiates a light to a sample gas, detects a scattered light from a particle included in the sample gas by a photoelectric conversion device, counts the number of the particles of every particle size division by the output voltage wave pattern of the photoelectric conversion device, calculate a time difference (Ta−T1) from a point (T1) being a peak of output voltage wave pattern and a point (Ta) being a falling detection threshold (A), when the time difference (Ta−T1) is beyond counting cancellation time (B), the output voltage wave pattern is not counted as a particle.
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Citations
4 Claims
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1. A method of particle counting, the method comprising:
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irradiating a sample gas with a light; detecting a scattered light from a particle included in the sample gas by a photoelectric conversion device; counting a number of the particles of every particle size division by an output voltage wave pattern of the photoelectric conversion device; and calculating, with a Digital Signal Processor (DSP), a time difference (Ta−
T1) with a point (T1) of a peak of output voltage wave pattern and a point (Ta) of a falling detection threshold (A), when the time difference (Ta−
T1) exceeds a counting cancellation time (B), the output voltage wave pattern is not counted as a particle. - View Dependent Claims (4)
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2. A method of particle counting, the method comprising:
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irradiating a sample gas with a light; detecting a scattered light from a particle included in the sample gas by a photoelectric conversion device; counting a number of the particles every particle size division by an output voltage wave pattern of the photoelectric conversion device, wherein the output voltage wave pattern has a plurality of peaks, and wherein a voltage value difference of each peak (Px) and a dip (Dx−
1) just before that of the peak exceeds a predetermined voltage value (C); andcalculating, with a Digital Signal Processor (DSP), a time difference (Ta−
Txm) with a point (Ta) of a falling detection threshold (A) and a point (Txm) just before that of the peak (Pxm), when the time difference (Ta−
Txm) exceeds a counting cancellation time (B), the output voltage wave pattern is not counted as a particle. - View Dependent Claims (3)
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Specification