The same is the light scattering, what is the difference between the dust particle counter and the dust detector

What is the difference between the dust particle counter and the dust detector The dust detector and the dust particle counter are instruments that detect the target particles through the scattering principle of light, but their application scenarios are very different, what is the difference between the two? Dust detector is mainly used to measure the atmospheric environment, suitable for all kinds of environmental research institutions, meteorology, public health, environmental supervision, air pollution research, the use of the environment is used in CDC, mining, metallurgy, power plants, chemical manufacturing, health supervision, environmental protection, environmental online monitoring, etc
.

The particle counter is used in clean rooms, such as medicine, electronics, precision machinery, semiconductors, biological engineering and other industries, the purification effect and cleanliness level of various clean levels of workbenches, purification chambers, purification workshops are monitored to ensure the production quality
of products.

So in addition to the different application scenarios, what is the specific difference between the dust detector and the dust particle counter? First of all, we introduce a word "aerosol", because of the epidemic in recent years, this word is believed to be familiar to everyone, that is, a gaseous dispersion system
composed of solid or liquid particles suspended in a gaseous medium.

The density of these solid or liquid particles can differ slightly from the density of the gaseous medium, or it can vary widely
.

The size of aerosol particles is usually between 0.
01 and 10 μm, but because of the source and the cause of formation is very large, for example: pollen and other plant aerosols have a particle size between 5-100 μm, wood and tobacco combustion of aerosols, the particle size is usually 0.
01-1000μm, so the shape of the particles is various, can be almost spherical, such as liquid fog beads, can also be flake, needle-like and other irregular shapes
.

From the perspective of fluid mechanics, aerosols are essentially multiphase fluids
with a continuous gaseous state and a solid and liquid state as a dispersed phase.

Clouds, fog, and dust in the sky, smoke from boilers used in industry and transportation and unburned fuels from various engines, solid dust from mining processes, quarry mining and stone processing and grain processing, artificial masking smoke screens and toxic fumes are all concrete examples
of aerosols.

What we call PM2.
5 and PM10 in our daily life are solid particulate matter in atmospheric aerosols
.

Therefore, the dust detector can also be called an aerosol detector
.

Dust detector Dust detector is to be measured by the air supply pump to inhale the aerosol to be measured into the detection chamber, the aerosol to be measured in the branch into two parts, a part of the filter is filtered as clean air after a high efficiency filter, as a protective sheath gas to protect the components of the sensor room from gas pollution
to be measured.

The other part of the aerosol enters the sensor chamber
directly as the sample to be tested.

In the sensor room, the main components are laser diodes, lens sets and photodetectors
.

During the detection process, the laser is first emitted by the laser diode, and a thin layer of light source
is formed through the lens group.

When a thin layer of light is illuminated on the aerosol to be measured flowing through the sensor chamber, it creates a scattering, and the scattered light intensity
of the light is detected by a photodetector.

The detector generates an electrical signal when illuminated by light, which is proportional to the mass concentration
of the aerosol.

This is then multiplied by the voltage calibration coefficient, which is obtained
by determining a specific concentration of aerosols.

Dust particle counter Dust particle counter principle: The particle counter draws the sampled gas
through a sampling pump.

In the laser chamber, the sampled gas is irradiated by the laser, and the frequency of the flash reflected by the particles represents the number of particles, and the reflected light intensity represents the particle size
of the particles.

Since the components in the laser chamber are not protected by sheath gas, the laser particle counter should be used in a clean environment to prevent damage
to the laser sensor.

When there is a loose particle material, dust source, spray place, it must be kept at least 12 inches away from the inlet and outlet pipes to avoid particle and liquid contamination of the sensor and pipeline
.

In summary, the laser dust meter not only adopts the sheath gas protection function of the clean gas path, the internal detection sensor structure is more complex, effectively protecting the components, preventing the components from being damaged by pollutants, so it can be used
for a long time in a relatively complex and heavily polluted environment.

The dust particle counter because the gas path design does not add sheath gas, coupled with the detection sensor structure is relatively simple, can only be classified according to several effective particle sizes, converted to dust concentration when the error is large (estimating the classification of 8 channels, the calculation error is greater than 30%; The grading of 2 channels, the calculation error is greater than 50%), so particle counting measurements can only be made in cleaner spaces
.

Through the above introduction, do you now know the difference between particle counters and dust detectors?