Method for determining the atmospheric dust concentration of GB 6921-86
Introduction
Atmospheric dust is a major source of urban air pollution and contributes to climate change. It is the top-priority pollutant and needs to be monitored and controlled. As one of the effective methods for dust monitoring and control, the atmospheric dust concentration has been paid close attention. GB 6921-86 is the standard for method of determining the dust concentration in the air. This article will discuss the main methodologies used in GB 6921 86.
Main content
This method is for the determination of atmospheric dust concentration in a single atmospheric environment. The method is suitable for determining the dust concentration of fine particles that are airborne, as well as coarse dust particles captured using an effective dust collection device. The atmospheric dust concentration is defined as the mass concentration of particles in the air, without considering the size of the particles.
The method uses two main pieces of equipment: an air sampler and a counter. The air sampler extracts the air from the atmosphere, and the counter is used to detect and count the number of dust particles in the air.
The air sampler consists of a fan and a micro-cyclone. The fan is used to pull the air in the atmosphere into the sampler, and the micro-cyclone is used to separate the dust particles from the air particles. The micro-cyclone is also used to collect the dust particles, which will be weighed prior to counting.
The counter is used to detect and count the number of dust particles collected by the air sampler. The counter is calibrated to accurately detect and count particles, and the results are the number of particles per cubic meter (PM).
At the end of the sampling and counting period, the number of particles detected is used to calculate the dust concentration of the atmosphere using a formula based on the weight of the particles multiplied by their volume. The dust concentration is then compared to the standards set by environmental regulations and standards.
Conclusion
The method for determining the atmospheric dust concentration of GB 6921-86is an effective way to measure the pollution in the environment. The method uses two main pieces of equipment; an air sampler and a counter, to accurately measure the number of particles in the air. The method is also used to compare the dust concentration of the atmosphere with the standards set by environmental regulations and standards. The method is suitable for measuring both fine and coarse dust particles, making it a versatile method for dust monitoring and control.
