CN111879672A - High-precision open type easily-maintained dust concentration detection device and method - Google Patents

Abstract

The invention relates to the technical field of dust concentration detection, in particular to a high-precision open type easily-maintained dust concentration detection device which comprises a base, wherein a detection area is arranged on the base, a laser emission unit, a light trap and a photoelectric conversion unit are arranged on the base, the laser emission unit and the light trap are respectively arranged on two opposite sides of the detection area, the photoelectric conversion unit is arranged on the upper side of the detection area, a shell is detachably arranged on the base and covers the detection area, a plurality of through holes are formed in the shell and communicated with the detection area, and the shell is arranged on the base, so that the influence of natural light on dust concentration detection can be reduced, and the detection precision of dust concentration is improved; the shell is detachably arranged on the base, so that the detection area, the laser emission unit, the light trap and the photoelectric conversion unit are conveniently maintained, and the convenient and fast maintenance effect is achieved.

Description

A high-precision open and easy-to-maintain dust concentration detection device and method

technical field

The invention relates to the technical field of dust concentration detection, in particular to a high-precision open-type and easy-to-maintain dust concentration detection device and method.

Background technique

At present, the detection technology for the concentration of dust particles mainly relies on the light scattering method. After the laser is irradiated to the dust particles, the dust particles change the irradiation direction of the laser light (ie, scattering), and the scattered light intensity is detected by the light sensing element. There is a correlation between the strength and the particle size and concentration of the dust particles. By measuring the intensity of scattered light, the detection of dust concentration and particle concentration is realized, which has the advantages of high sensitivity and good real-time performance.

In the current technical solution, one is to pump the dust into the detection darkroom through a fan. This solution has the advantages of high detection accuracy, good stability, and less influence by external natural light. However, it is difficult to clean the detection element after it is contaminated. During the cleaning process It is easy to damage the laser element, and the maintenance process of the detection device is cumbersome during use, which limits the popularization and application of this technology; the other is to realize the detection of dust concentration by means of no power and free diffusion. Affected by natural light, the detection accuracy is low and unstable.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a high-precision, open-type and easy-to-maintain dust solution for the problems that the prior art dust concentration detection device adopts a detection darkroom, which is inconvenient to maintain, or the dust concentration detection device is greatly affected by natural light and has low detection accuracy. Concentration detection device and method.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

A high-precision, open and easy-to-maintain dust concentration detection device includes a base, a detection area is arranged on the base, a laser emission unit, an optical trap and a photoelectric conversion unit are arranged on the base, and the laser emission unit and the The light traps are respectively arranged on opposite sides of the detection area, the photoelectric conversion unit is arranged on the upper side of the detection area, and a casing is detachably provided on the base, and the casing covers the detection area, The casing is provided with a plurality of through holes, and the through holes communicate with the detection area.

As a preferred solution of the present invention, the base is provided with a light-shielding plate, the light-shielding plate is disposed on the side of the detection area, and the light-shielding plate is fixed on both sides of the photoelectric conversion unit to block the clutter of the laser from entering the photoelectric In the conversion unit, avoid causing large noise and affecting the detection accuracy.

As a preferred solution of the present invention, the base is further provided with a deflector, the deflector and the shading plate are fixed to form a frame-shaped structure, and the inner side of the deflector is arranged on an inclined plane, so that the photoelectric conversion unit is It is convenient for dust to gather at the bottom, which improves the detection accuracy of the photoelectric conversion unit. The inclined surface of the deflector is set to facilitate the flow of dust. On the other hand, it can block natural light from entering the detector, which can effectively avoid the influence of natural light on the detection device.

As a preferred solution of the present invention, a heat dissipation sleeve is fixed on the base, fins are fixed on the heat dissipation sleeve, and the heat dissipation sleeve is sleeved on the laser emitting unit to dissipate heat from the laser emitting unit to avoid excessive temperature. The laser power of the laser emitting unit is changed, and the error of the detection result is increased.

As a preferred solution of the present invention, the photoelectric conversion unit is electrically connected with a main control board, the main control board is arranged in the base, the photoelectric conversion unit converts the received optical signal into an electrical signal, and the main control board converts the electrical signal into an electrical signal. The signal is converted into a digital signal, and the specific value of the concentration is calculated.

As a preferred solution of the present invention, the upper end of the base is provided with a body, the body is provided with a circuit board electrically connected to the main control board, the circuit board is electrically connected with a display screen, and the display screen is provided with On the main body, the real-time concentration value is displayed on the display screen, which is easy to observe. Of course, in order to avoid the impact of excessive dust concentration on the physical and mental health of the staff, an alarm device can be electrically connected to the main control board. After the dust concentration range is reached, the alarm will be issued, and the dust reduction operation will be carried out through the dust reduction device.

As a preferred solution of the present invention, the photoelectric conversion unit is a silicon photovoltaic cell, a filter is provided on the side of the silicon photovoltaic cell close to the detection area, the main control board is a silicon photovoltaic cell control circuit board, and the silicon photovoltaic cell The control circuit board is fixed on the base, and converts the electrical signal converted by the silicon photocell into a digital signal, which is used to convert the optical signal of the laser emitting unit into an electrical signal. The effective response band of the silicon photocell is 635nm, and the filter It is a 635nm bandpass filter, which can effectively block the light intensity beyond 635nm, reduce the interference of external natural light, and improve the detection accuracy.

As a preferred solution of the present invention, a hook is arranged above the main body, a plug is arranged on the main body, the plug is electrically connected with the main control board, the hook is used to place the main body, and the plug is connected to the power supply through cooperation with the socket, Provide power for the main control board, and the plug can be an aviation plug.

As a preferred solution of the present invention, the base is provided with a light outlet, the laser emission port of the laser emitting unit is aligned with the light outlet, the base is also provided with a light inlet, and the light trap is aligned with the light trap. The light inlet, the light outlet and the light inlet are all set in the shape of a horn to avoid the leakage of stray light of the laser beam and reduce the influence on the measurement of dust concentration by the photoelectric conversion unit. The laser emission unit has a laser emitted by the light outlet. Part of the heat is dissipated on the dust particles, and part is absorbed into the light trap through the light inlet.

A high-precision, open and easy-to-maintain dust concentration detection method, firstly open the dust concentration detection device, turn off the laser, collect natural light data, and calculate the influence value of natural light on the dust concentration; then turn on the laser to measure the dust concentration; The dust concentration measured in the open state of the laser is subtracted from the effect of natural light on the dust concentration measured in the laser off state to obtain the real dust concentration.

As a preferred solution of the present invention, when the laser is turned off, the dust concentration values S under n groups of natural light are collected, and the median value SP=[max(S)-min(S)]/2 of the array is calculated; where S1, S2...Sn represents the n concentration values collected; max(S) represents the maximum value of the collected data; min(S) represents the minimum value of the collected data; SP represents the median value of the collected data;

The threshold of the median value is: YZ=SP*T; wherein, YZ is the calculated threshold; T is the coefficient of threshold filtering, 0<T<1;

Filter the dust concentration value M within the threshold fluctuation range, M={M|SP-YZ<S<SP+YZ}, where M is the data filtered by the median threshold, and the number of data is Q, Q≤n;

Calculate the mean Z of the median-threshold filtered data;

Z=(M1+M2+...+M _Q )/Q;

Among them, Z is the mean value of the calculated natural light signal after median threshold filtering; M1, ... M _Q are the values in the Q group of data; Q is the number of data in the M group.

According to the above operation, the influence of natural light on the dust concentration during the detection of the dust concentration is reduced, and the accuracy of the detection of the dust concentration is improved.

As a preferred solution of the present invention, when the laser is turned on, the dust concentration values Y in r groups of laser states are collected, which are Y1, Y2... Yr respectively;

The array after removing the influence of natural light signal is YP, YP _r =Y _r -Z; wherein YP _r is the data that removes the influence of natural light signal;

Calculate the average CP of the data without the influence of natural light signals;

CP=(YP1+YP2+...+YP _r )/r;

Corrections to Calculation Results

C=CP*K, where C is the output dust concentration value, and K is the correction proportional coefficient.

This improves the accuracy of detecting the dust concentration.

Compared with the prior art, the beneficial effects of the present invention:

1. Install the high-precision open and easy-to-maintain dust concentration detection device to the place where the dust concentration needs to be detected. The dust enters the detection area through its own floating through the through hole of the casing. The laser emitting unit emits laser light to irradiate the dust, and the laser enters the optical trap. The photoelectric conversion unit converts the optical signal of the laser light scattered by the dust into an electrical signal to detect the dust concentration. Since the shell is set on the base, the influence of natural light on the detection of dust concentration can be reduced and the detection of dust concentration can be improved. Accuracy; the detachable setting of the casing and the base facilitates the maintenance of the detection area, the laser emission unit, the optical trap and the photoelectric conversion unit, achieving the effect of convenient and quick maintenance, thereby reducing the maintenance cost.

Description of drawings

Fig. 1 is the structural representation of base;

Fig. 2 is the enlarged view of A place in Fig. 1;

Fig. 3 is the structural representation that the base is the shell assembly;

Fig. 4 is the structural representation of the present invention;

Fig. 5 is the sectional view of Fig. 4;

Fig. 6 is the flow chart of this method;

Markings in the figure: 1- base, 2- detection area, 3- laser emission unit, 4- optical trap, 5- photoelectric conversion unit, 6- shell, 7- through hole, 8- shield plate, 9- guide plate, 10- Cooling sleeve, 11- Fin, 12- Main control board, 13- Main body, 14- Circuit board, 15- Display screen, 16- Optical filter, 17- Hook, 18- Plug, 19- Light outlet, 20 - Light inlet, 21- nameplate.

Detailed ways

The present invention will be further described in detail below in conjunction with test examples and specific embodiments. However, it should not be construed that the scope of the above-mentioned subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

Example 1

As shown in Fig. 1-Fig. 3, a high-precision open and easy-to-maintain dust concentration detection device includes a base 1, a detection area 2 is arranged on the base 1, and a laser emission unit 3, Optical traps 4 and photoelectric conversion units 5, the laser emission unit 3 and the optical traps 4 are respectively arranged on opposite sides of the detection area 2, and the photoelectric conversion units 5 are arranged on the detection area 2 On the side, a casing 6 is detachably provided on the base 1 , the casing 6 covers the detection area 2 , and a plurality of through holes 7 are provided on the casing 6 , and the through holes 7 communicate with the detection area 2 In the present embodiment, the outer shell 6 is connected with the base 1 by bolts, and the detection area 2 is the U-shaped groove that is set on the base 1, and the detection area 2 is directly communicated with the outside when the outer shell 6 is not installed, and through the communication on the outer shell 6. The hole 7 connects the detection area 2 with the outside world, so that the dust can float into the detection area 2, and the dust concentration detection can be performed while avoiding the interference of natural light through the outer casing 6, and the detachable setting of the outer casing 6 is convenient for the detection area 2 and laser emission. The maintenance of the unit 3, the optical trap 4 and the photoelectric conversion unit 5 reduces the maintenance cost. The optical trap 4 is coated with a black material to ensure that the laser light entering the optical trap 4 is fully absorbed.

As shown in FIG. 1 and FIG. 2 , the base 1 is provided with a light shielding plate 8 , the light shielding plate 8 is arranged on the side of the detection area 2 , and the light shielding plate 8 is fixed on both sides of the photoelectric conversion unit 5 , In order to prevent the clutter of the laser from entering the photoelectric conversion unit 5, to avoid causing large noise and affecting the detection accuracy; the base 1 is also provided with a deflector 9, and the deflector 9 is fixed with the shading plate 8 A frame-shaped structure is formed, and the inner side of the deflector 9 is provided with an inclined surface, which makes it easy to collect dust under the photoelectric conversion unit 5, and improves the detection accuracy of the photoelectric conversion unit 5, and the deflector 9 is provided with an inclined surface to facilitate the flow of dust; The photoelectric conversion unit 5 is arranged above the middle of the rectangular frame formed by the shading plate 8 and the guide plate 9, and the lowest point of the shading plate 8 and the guide plate 9 is higher than the laser beam emitted by the laser emission unit 3, which is convenient for the photoelectric conversion unit. 5 Accumulate dust as much as possible while receiving the signal.

As shown in FIG. 1 , a heat dissipation sleeve 10 is fixed on the base 1 , fins 11 are fixed on the heat dissipation sleeve 10 , and the heat dissipation sleeve 10 is sleeved on the laser emitting unit 3 . Heat dissipation is performed to prevent the laser power of the laser emitting unit 3 from changing due to excessive temperature, resulting in an increase in the error of the detection result.

As shown in FIG. 1 , the photoelectric conversion unit 5 is electrically connected with a main control board 12 , and the main control board 12 is arranged in the base 1 . The photoelectric conversion unit 5 converts the received optical signal into an electrical signal, and the main control board 12 is The control board 12 converts the electrical signal into a digital signal, and calculates the specific value of the concentration.

As shown in FIG. 4 and FIG. 5 , the upper end of the base 1 is provided with a main body 13 , the main body 13 is provided with a circuit board 14 electrically connected to the main control board 12 , and the circuit board 14 is electrically connected with a circuit board 14 . Display screen 15, the display screen 15 is arranged on the main body 13, and the display screen 15 displays the real-time concentration value, which is convenient for observation. 12 Power on and connect to the alarm device. After the dust concentration exceeds the dust concentration range of the staff, the alarm will be issued, and the dust reduction operation will be carried out through the dust reduction device.

In this embodiment, the photoelectric conversion unit 5 is a silicon photovoltaic cell, a filter 16 is provided on the side of the silicon photovoltaic cell close to the detection area 2 , the main control board 12 is a silicon photovoltaic cell control circuit board, and the The silicon photovoltaic cell control circuit board is fixed on the base 1 and converts the electrical signal converted by the silicon photovoltaic cell into a digital signal for converting the optical signal of the laser emitting unit 3 into an electrical signal.

As shown in FIG. 4 and FIG. 5 , a hook 17 is arranged above the main body 13 , a plug 18 is arranged on the main body 13 , the plug 18 is electrically connected to the main control board 12 , and the hook 17 is used to place the main body 13. The plug 18 provides power for the main control board 12 by being connected to the power supply in cooperation with the socket. The plug 18 can specifically be an aviation plug. A nameplate 21 is provided on the outer surface of the main body 13 for recording the model of the unpowered dust concentration detection device, etc. .

As shown in FIG. 1 , in this embodiment, the base 1 is provided with a light exit port 19 , the laser emission port of the laser emitting unit 3 is aligned with the light exit port 19 , and the base 1 is also provided with a light input port 19 . The light trap 4 is aligned with the light inlet 20, the light outlet 19 and the light inlet 20 are both set in a horn shape to avoid the leakage of stray light of the laser beam and reduce the impact on the photoelectric conversion unit 5 Measure the effect of dust concentration.

The specific workflow of the application: the high-precision open-type and easy-to-maintain dust concentration detection device is installed in the area where the dust concentration needs to be measured through the hook 17, the dust enters the detection area 2 through the through hole 7 of the casing 6 through its own floating, and the laser The laser light emitted by the emission unit 3 is irradiated on the dust and scattered, and the laser light that is not irradiated to the dust enters the optical trap 4 and is absorbed. Process and display the real-time dust concentration on the display screen 15, thereby reducing the influence of natural light on the detection of dust concentration, improving the detection accuracy of dust concentration, and the detachable setting of the housing 6 is convenient for the detection area 2, the laser emission unit 3, the light Maintenance of the trap 4 and the photoelectric conversion unit 5 reduces maintenance costs.

As shown in Figure 6, a high-precision open-type and easy-to-maintain dust concentration detection method firstly turns on the dust concentration detection device, turns off the laser, collects natural light data, and calculates the effect of natural light on the dust concentration; then turns on the laser , measure the dust concentration; finally, the real dust concentration is obtained by subtracting the effect of natural light on the dust concentration measured in the laser off state from the dust concentration measured in the open state of the laser.

Specifically, when the laser is turned off, the dust concentration values S under n groups of natural light are collected, and the median value SP=[max(S)-min(S)]/2 of the array is calculated; among them, S1, S2...Sn represents the n concentration values collected; max(S) represents the maximum value of the collected data; min(S) represents the minimum value of the collected data; SP represents the median value of the collected data;

The threshold of the median value is: YZ=SP*T; wherein, YZ is the calculated threshold; T is the coefficient of threshold filtering, 0<T<1;

Filter the dust concentration value M within the threshold fluctuation range, M={M|SP-YZ<S<SP+YZ}, where M is the data filtered by the median threshold, and the number of data is Q, Q≤n;

Calculate the mean Z of the median-threshold filtered data;

Z=(M1+M2+...+M _Q )/Q;

Among them, Z is the mean value of the calculated natural light signal after median threshold filtering; M1, ... M _Q are the values in the Q group of data; Q is the number of data in the M group.

According to the above operation, the influence of natural light on the dust concentration during the detection of the dust concentration is reduced, and the accuracy of the detection of the dust concentration is improved.

Specifically, when the laser is turned on, the dust concentration values Y in the laser state of the r groups are collected, which are Y1, Y2...Yr respectively;

The array after removing the influence of natural light signal is YP, YP _r =Y _r -Z; wherein YP _r is the data that removes the influence of natural light signal;

Calculate the average CP of the data without the influence of natural light signals;

CP=(YP1+YP2+...+YP _r )/r;

Corrections to Calculation Results

C=CP*K, where C is the output dust concentration value, and K is the correction proportional coefficient.

This improves the accuracy of detecting the dust concentration.

In this embodiment, the n groups of dust concentrations collected under natural light are 600 groups, and the dust concentrations collected under laser light are 600 groups, which ensure the accuracy of the dust concentration threshold and the accuracy of the measured dust concentration results.

As shown in Figure 6, by calculating the average value of the collected dust concentration in the state of natural light, and then collecting the dust concentration value when the laser is turned on, the average value of the dust concentration collected under the natural light is subtracted from the dust concentration value collected under the laser charging The value of dust concentration can be obtained with higher precision and the influence of natural light noise can be reduced.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. within.

Claims (9)

1. The utility model provides a dust concentration detection device that high accuracy open was easily maintained, a serial communication port, including base (1), be provided with detection zone (2) on base (1), be provided with laser emission unit (3), light trap (4) and photoelectric conversion unit (5) on base (1), laser emission unit (3) with light trap (4) set up respectively the relative both sides of detection zone (2), photoelectric conversion unit (5) set up the upside of detection zone (2), can dismantle on base (1) and be provided with shell (6), shell (6) cover detection zone (2), be provided with a plurality of through-holes (7) on shell (6), through-hole (7) with detection zone (2) intercommunication.

2. A high-precision open easy-maintenance dust concentration detection device according to claim 1, characterized in that a light shielding plate (8) is arranged on the base (1), the light shielding plate (8) is arranged on the side of the detection area (2), and the light shielding plate (8) is fixed on two sides of the photoelectric conversion unit (5); the base (1) is also provided with a guide plate (9), and the guide plate (9) and the shading plate (8) are fixed to form a frame-shaped structure.

3. The high-precision open type easy-maintenance dust concentration detection device according to claim 1, wherein a heat dissipation sleeve (10) is fixed on the base (1), a fin (11) is fixed on the heat dissipation sleeve (10), and the heat dissipation sleeve (10) is sleeved on the laser emission unit (3); the photoelectric conversion unit (5) is electrically connected with a main control board (12), and the main control board (12) is arranged in the base (1).

4. A high-precision open type easy-maintenance dust concentration detection device according to claim 3, wherein a body (13) is arranged at the upper end of the base (1), a circuit board (14) electrically connected with the main control board (12) is arranged on the body (13), a display screen (15) is electrically connected to the circuit board (14), and the display screen (15) is arranged on the body (13).

5. The open dust concentration detection device that easily maintains of high accuracy according to claim 4, characterized in that, photoelectric conversion unit (5) is silicon photocell, and the silicon photocell is provided with light filter (16) near detection region (2) one side, and main control board (12) is silicon photocell control circuit board, and silicon photocell control circuit board is fixed on base (1).

6. A high-precision open type easy-to-maintain dust concentration detection device according to claim 1, wherein a light outlet (19) is provided on the base (1), the laser emission port of the laser emission unit (3) is aligned with the light outlet (19), a light inlet (20) is further provided on the base (1), the optical trap (4) is aligned with the light inlet (20), and the light outlet (19) and the light inlet (20) are both horn-shaped.

7. A high-precision open type easily-maintained dust concentration detection method is characterized in that firstly, a dust concentration detection device is opened, a laser is closed, natural light data are collected, and an influence value of natural light on dust concentration is calculated; then, turning on a laser and measuring the dust concentration; and finally, subtracting the influence value of the natural light dust concentration measured in the closed state of the laser from the dust concentration measured in the open state of the laser to obtain the real dust concentration.

8. A high-precision open easy-maintenance dust concentration detection method according to claim 7, characterized in that when the laser is turned off, dust concentration values S under n groups of natural light are collected, and a median SP ═ max (S) -min (S) ]/2 of the groups is calculated; wherein, S1 and S2 … … Sn represent n collected concentration values; max(s) represents the maximum value of the acquired data; min (S) represents the minimum value of the acquired data; SP represents the median of the collected data;

the threshold for the median is: YZ ═ SP × T; wherein YZ is a calculated threshold; t is the coefficient of threshold value filtration, and T is more than 0 and less than 1;

screening a dust concentration value M in a threshold fluctuation range, wherein M is { M | SP-YZ < S < SP + YZ }, M is data after median threshold filtering, the number of data is Q, and Q is less than or equal to n;

calculating an average value Z of the data after median threshold filtering;

Z＝(M1+M2+……+M_Q)/Q；

wherein Z is the mean value of the natural light signal after median threshold value filtering; m1, … … M_QIs a numerical value in the Q group data; q is the number of data in the M array.

9. The method of claim 8, wherein when the laser is turned on, r sets of values of dust concentration Y in laser state are collected, Y1 and Y2 … … Yr respectively;

the array without the influence of natural light signal is YP, YP_r＝Y_r-Z; wherein YP_rRemoving data influenced by natural light signals;

calculating an average value CP of data without the influence of the natural light signal;

CP＝(YP1+YP2+……+YP_r)/r；

correction of calculation results

And C is CP K, wherein C is the output dust concentration value, and K is the correction scale factor.

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