CN103353471A

CN103353471A - Device for measuring air pollution

Info

Publication number: CN103353471A
Application number: CN2013103199008A
Authority: CN
Inventors: 张伟
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-07-29
Filing date: 2013-07-29
Publication date: 2013-10-16

Abstract

The invention provides a device for measuring air pollution, which comprises an air quality VOC sensor module, an amplifying module, an A/D transverter module, a heater module, a control algorithm unit module and a two-wire serial bus module; the air quality VOC sensor module, the amplifying module and the A/D transverter module are electrically connected with the control algorithm unit module; the heater module is electrically connected with the control algorithm unit module; the control algorithm unit module is electrically connected with the amplifying module and the two-wire serial bus module separately. The device provided by the invention has the advantages that the equivalent calculation of the density of CO2 can be realized through a semiconductor sensor. The method is mature in manufacturing technology, facilitates miniaturize integrated circuit design, is large in batch, can be manufactured automatically, and is low in cost.

Description

A kind of measurement air-polluting device

Technical field

The present invention relates to a kind of measurement air-polluting device.

Background technology

Carbon dioxide is compound common in the air, and its molecular formula is CO2, is a kind of colorless and odorless gas under the normal temperature, and the density ratio air is bigger, can be water-soluble.The main source of greenhouse effect, a small amount of dioxy fossil-carbon to human body without harm, but the excessive breathing that can affect the people, blood carbonic acid increases, the generation acidosis.

The carbon dioxide molecule structure is very stable, the chemical property torpescence, and the carbon dioxide measuring method has infrared absorption process at present, chemical method, electrochemical process, gas chromatography, the shortcoming of the method is the cost height, universality is poor, algorithm is complicated, equipment volume is large etc.

Summary of the invention

The present invention provides a kind of method of utilizing semiconductor VOC sensor to measure CO2 concentration in the air by method of equal effects in order to solve a difficult problem of measuring CO2 concentration; Also can directly express according to the mode of 0%-100% according to the pollution level of VOC air quality simultaneously.

For solving the problems of the technologies described above, the present invention realizes as follows: a kind of measurement air-polluting device comprises air quality VOC sensor assembly, amplifier module, A/D converter module, heater module, control algolithm unit module and two-wire serial bus module; Described air quality VOC sensor assembly, described amplifier module, described A/D converter module are electrically connected with described control algolithm unit module successively; Described heater module is electrically connected with described control algolithm unit module; Described control algolithm unit module is electrically connected with described amplifier module and described two-wire serial bus module respectively.

Good effect of the present invention is:

The present invention can equivalent CO2 gas concentration by semiconductor transducer. and the method manufacturing process is ripe, is convenient to the Miniaturized Integrated Circuit design, and is large in batches, and automated production is with low cost;

Need not after the VOC sensor digitized processing to demarcate, produce simplyr, user's secondary development need not gas professional knowledge can finish other circuit design;

Adopt I2C, RS485, the way of outputs such as 232, PWM, mode signal output can satisfy any request for utilization of user flexibly.

Description of drawings

Fig. 1 is structural representation of the present invention.

Embodiment

The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments.

As shown in Figure 1, measurement air-polluting device of the present invention comprises air quality VOC sensor assembly, amplifier module, 12 A/D converter modules, heater module, voltage and current detection circuit module, CRC register module, control algolithm unit module and two-wire serial bus modules.

VOC sensor assembly, amplifier module, 12 A/D converter modules are electrically connected with the control algolithm unit module successively; Heater module, voltage and current detection circuit module, CRC register module are electrically connected with the control algolithm unit module respectively; The control algolithm unit module is electrically connected with amplifier module and two-wire serial bus module respectively.

Its principle of work is: electrical heating VOC sensor assembly, gather the corresponding voltage that changes of resistance of its variation again by the amplifier module amplifying signal, change digital signal into by 12 A/D converter modules biographies again and pass to the control algolithm unit module, data are exported via two-wire serial bus module or PWM mode after processing.

Convert CO2 concentration to by formula.Seek under the typical environment (in the automobile, indoor, outdoor etc., wherein indoorly refer to that namely any people of having may movable place), the increase and decrease amount of CO2 gas concentration and other gas concentrations is contained number and is concerned.

In automobile, indoor, outdoor three kinds of activity spaces are contained the foundation of number mathematical model, express respectively equipotent concentration or the pollution level of CO2. the typical algorithm formula:

VOC measures and represents with following several grade modes

A, dustiness 0-100%, soiling value is 0% in clear bright air, is 100% when being the sensor values maximum in turbid air)

B, (clear bright airborne CO2 concentration is about 350-500PPM to the equivalently represented method of 0-80000PPMCO2, and the concentration of CO2 can reach 80000PPM even higher under high pollution) 014 simulating signal with the VOC sensor measurement is converted to I2C by single-chip microcomputer, RS485, but 232 modes are exported also PWM output duty cycle (0-100% or 0-80000PPM etc.)

Whole sensor adopts the automatic background concentration method automatically to revise, and does not need manual synchronizing. so that this sensor obtains large spoke degree prolongation serviceable life, can reach more than 15 years like this.

Specific implementation method is as follows, powers on (5V contains following direct current) to sensor assembly, and add 10NF electric capacity between VDD and GND

Ground, this module I 2C ground is OX02,7 ground;

The read data mode is returned 3 byte datas+do not reply+position of rest for sending out a start bit+address bit OX02+ function code OX03+ module;

Module is 0-100 by first byte of I2C return data, and the duty ground of being exported by the PWM pin also corresponds to 0-100%;

Module is 0-8000 by the second, the three byte of I2C return data, i.e. corresponding current gas concentration 0-8000PPM;

Deposit data form sampling sexadecimal, high-order at front low level rear.

Good effect of the present invention:

This device can equivalent CO2 gas concentration. and the method manufacturing process is ripe, is convenient to the Miniaturized Integrated Circuit design, and is large in batches, and automated production is with low cost;

Represent air quality with straightaway CO2 concentration (0-8000PPM):

380ppm-450ppm: outdoor fresh air; 450ppm-1000ppm: recommend indoor air quality; 1000-5000: limit value; 5000PPM-15000PPM: danger; 15000PPM-80000PPM: may be dead; (user also can set up scope on their own according to environment for use)

020VOC soiling value (0-100%) expression pollution level, user Geng Yi accepts, and also can better know from experience VOC air-polluting connotation. and be easy to the user and understand and the environmental protection popularization.

0～30%: pure and fresh; 30-50%: normal; 50%-70%: relatively poor; 70-100%: seriously polluted.(user also can set up scope on their own according to environment for use)

Claims

1. measure the air-polluting device for one kind, it is characterized in that, comprise air quality VOC sensor assembly, amplifier module, A/D converter module, heater module, control algolithm unit module and two-wire serial bus module; Described air quality VOC sensor assembly, described amplifier module, described A/D converter module are electrically connected with described control algolithm unit module successively; Described heater module is electrically connected with described control algolithm unit module; Described control algolithm unit module is electrically connected with described amplifier module and described two-wire serial bus module respectively.

2. a kind of measurement air-polluting device according to claim 1 is characterized in that, also comprises voltage and current detection circuit module and register module; Described voltage and current detection circuit module and described register module are electrically connected with described control algolithm unit module respectively.