System for monitoring PM2.5 by smart phone

Abstract

The invention discloses a system for monitoring PM2.5 by a smart phone. The networked system is rapid and light and is low in cost. In addition to the general smart phone, the system is also provided with a small and intelligent air sampling head. The intelligent air sampling head can perform inhaling sampling through a human mouth and also can perform sampling by a sampling air pump. The intelligent air sampling head and the smart phone can communicate with each other. The intelligent air sampling head measures the number and particle size of dust in air by a laser scattering method under the guide of the smart phone, the gas flow is measured by a capillary heat transfer temperature difference measurement method, and the measurement result is transmitted to the smart phone for processing and displaying. The smart phone wirelessly uploads the location of the smart phone and the measurement result of PM2.5, so that nationwide automatic PM2.5 networking coverage is realized, and the pollution source and diffusion direction are determined. According to the system, the intelligent air sampling head can be automatically maintained and corrected by a user under the guide of the smart phone.

Description

technical field [0001] The invention relates to the field of atmospheric monitoring, in particular to a system for monitoring PM2.5 with a smart phone. Background technique [0002] The smog is making big cities in China and even the whole world tense. Particles with a diameter of less than 7 microns can stay in the atmosphere for a long time and float with the wind to all parts of the world. When particles with a diameter of less than 2.5 microns enter the human body, they will block the micro-organisms of the human body. Circulation, and directly block the lungs, resulting in a reduction in lung capacity and hardening of the lungs. A large amount of data has proved that lung cancer, which has risen to the number one cancer in China, is directly related to smog. Similarly, due to the use of a large number of plastics and other industrial products, these plastic products will age and become dust and enter the water source. The human body's filtering effect on tiny particles...

AI Technical Summary

Problems solved by technology

Air sampling uses a sampling pump. The sampling air flow rate of the sampling pump is basically stable. Therefore, the laser particle counters currently on the market can easily and conveniently measure the volume of gas flowing through, but they cannot dilute the incoming air. When dirty, the particle count and size cannot be accurately measured

In addition, the sampling pump occupies a certain volume and consumes a lot of power

This type of instrument currently on the market has the following disadvantages: (1) It consumes a lot of power and needs to be equipped with a large-capacity battery (up to 2000mAh); (2) It is heavy and inconvenient to carry; (3) It is expensive and expensive (the cheapest (4) did not take advantage of the popularization of smart phones, could not automatically add test location information, and could not automatically network the whole city and the whole country; (5) directly extract air when sampling, When it is too dirty, the laser scattering method will miss counts, resulting in inaccurate results

(6) The user cannot calibrate the instrument anytime and anywhere by himself, which affects the credibility of the measurement results

[0006] For the processing of particle laser scattering photoelectric signals, the current handheld PM2.5 tester uses the pulse comparison counting method, which will produce Leakage counting (the photoelectric pulse corresponding to the dust is too dense to be distinguished), and the comparison threshold used cannot change with the background signal, and the background depends on the pollution in the laser counting cavity and the oxidation degree of the reflective surface, the laser Power changes, contamination of each mirror, etc., so the measurement results will inevitably drift

In addition, the user cannot correct it by himself, so the existing instrument error will be uncontrollable

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