airborne particle counterIt is a specialized instrument for testing the particle size and distribution of airborne dust particles, developed from microscopes, and has gone through the processes of microscopes, settling tubes, settling instruments, centrifugal settling instruments, particle counters, laser air particle counters, and PCS nano laser air particle counters. Due to its advantages such as fast testing speed, wide dynamic distribution, and no human influence, laser air particle counters have become mainstream products in many industries in recent years and are widely used.
airborne particle counterWorking principle:
Particles in the air scatter when exposed to light, a phenomenon known as light scattering. Light scattering is related to factors such as particle size, wavelength of light waves, refractive index of particles, and absorption characteristics of particles towards light. However, in terms of scattered light intensity and particle size, there is a basic rule that the intensity of scattered light from particles increases with the increase of their surface area. In this way, by measuring the intensity of scattered light, the size of particles can be inferred, which is the basic principle of light scattering particle counters.
In fact, the scattered light intensity generated by each particle is very weak, which is a small light pulse. It needs to be amplified by a photoelectric converter to convert the light pulse into an electrical pulse with a larger signal amplitude, and then further amplified and screened by electronic circuits to complete the counting of a large number of electrical pulses. At this point, the number of electrical pulses corresponds to the number of particles, and the amplitude of the electrical pulses corresponds to the size of the particles.
The specific working principle of the air particle counter: The light from the light source is focused by lens group 1 into the measurement chamber. When each particle in the air quickly passes through the measurement chamber, the incident light is scattered once, forming a light pulse signal. This optical signal is sent to the photodetector through lens group 2, which is proportionally converted into an electrical pulse signal. After amplification and discrimination by the instrument's electronic circuit, the required signal is picked out and displayed through the counting system.
Classified by different standards:
1. According to the testing principle: scattered light method testing (white light, laser), microscope method testing, weighing method testing, DMA method testing (particle size analyzer), inertia method testing, diffusion method testing, condensed nucleus method testing (CNC), etc.
2. By flow rate: small flow rate of 0.1cfm (2.83L/min), large flow rate of 1cfm (28.3L/min)
3. By shape and volume: handheld, desktop
4. According to the testing channel: single channel (only measuring a certain particle size); Dual channel (testing two particle sizes); Multi channel (testing multiple particle sizes)
5. Other: The application areas of particle counters include the pharmaceutical industry, air conditioning purification industry, electronics industry, food hygiene industry, epidemic prevention department, research institute, optics, high-efficiency filters (HEPA), precision printing, and aerospace industry.