CN111899494A - Quantitative detection device and method for point-type smoke-sensing fire detector - Google Patents

Abstract

The invention provides a quantitative detection device and method for a point-type smoke detector, which relate to the technical field of smoke detection. The device includes a detection terminal, a control terminal and a tripod; the method improves that the traditional detection device cannot accurately judge the response degree of the fire alarm system to the fire signal on the scene, and cannot accurately and objectively evaluate the real situation that the detection system can achieve in the situation. Defects in the degree of protection have the advantages of easy operation, short measurement period, high precision, easy portability, easy application and maintenance, and stable and reliable performance.

Description

Quantitative detection device and method for point-type smoke detector

technical field

The invention relates to the technical field of smoke detection, in particular to a quantitative detection device and method for a point-type smoke detector.

Background technique

Point-type smoke detectors are the most commonly used fire detectors and the main equipment in the automatic fire alarm system. The comprehensive performance of the reliability of the main parameters and the stability of the main parameters are the key factors that determine the performance of the entire automatic fire alarm system. At present, the engineering application of point-type smoke detectors has the following characteristics:

1) With the continuous increase of new buildings, there are many point-type smoke detectors newly installed and used in my country every year, which can reach tens of millions;

2) A large number of installed point-type smoke detectors have been polluted for a long time or are approaching the service life. Since the 1980s, most of the detectors installed and used in engineering have reached the limit of pollution due to the different environments used, and are in urgent need of maintenance.

3) The concentration of the smoke source detected by the existing smoker is uncontrollable and not environmentally friendly. At present, the smokers used in the field of fire engineering inspection in my country generally use stick incense sticks, mosquito coils, etc. as the smoke source. Not only the amount of smoke is uncontrollable, but also it has certain pollution to the detector itself and the environment.

4) There is no on-site quantitative detection device for smoke detectors in China. At present, the smokers used in the field of fire engineering detection in my country are all the alarm functions of qualitative detection detectors, and the response threshold of the detectors cannot be quantitatively measured.

The National Fire Alarm Code NFPA72 is the only general fire alarm code in the United States. The regulation stipulates that all installed smoke detectors must undergo visual inspection up to six months after the initial acceptance test, and an annual functional test up to one year after the acceptance test. And it must be ensured that the sensitivity of each smoke detector is within its registered sensitivity range. If the detector sensitivity is found to be outside its registered sensitivity range, it must be cleaned, re-calibrated or replaced.

In my country, a series of regulations have been made in the following national standards and specifications for the on-site detection of point-type smoke detectors:

(1) Article 6.2.1 of GA 588-2012 "Rules for On-site Judgment of Fire Products" stipulates the inspection items, inspection methods and detection instruments for on-site inspection of point-type smoke detectors.

(2) Articles 4.3.1.1 and 5.3.1.1 of GA 503-2004 "Technical Regulations for the Detection of Fire Protection Facilities in Buildings" stipulate that point-type smoke detectors should be able to carry out alarm functions, fire alarm transmission functions, and alarm confirmation light display function, etc.

(3) Article 4.4.2 of GB 50166-2014 "Code for Construction and Acceptance of Automatic Fire Alarm System" stipulates the debugging of point-type smoke detectors, and Articles 5.1.5 and 5.1.9 are for point-type smoke detectors The on-site determination and acceptance methods of detectors are stipulated.

(4) Article 3.3.2 of GB 29837-2013 "Maintenance and Scrap of Fire Detection and Alarm Products" stipulates that after the smoke detector is repaired, the response threshold test should be carried out. Article 4.3.2 stipulates that the detector response threshold should be calibrated after cleaning.

In the above-mentioned national standards and specifications, the basic requirements for point-type smoke detectors on the project site are to perform functions such as alarm and reset. The response threshold tests specified in GB 29837-2013 are all carried out in the laboratory. Response threshold is the most important performance index of point-type smoke detector in field application, which is directly related to the response time of detector to fire and the stable operation of fire detection and alarm system.

Due to the limitation of current on-site detection technology, it is still impossible to accurately measure the response threshold of point-type smoke detectors at the engineering site in China. At present, the method of testing by lighting a cigarette or a cigarette lighter is commonly used, and there are the following outstanding problems:

1) The smoke source of these devices is neither stable, nor repeatable and reproducible, and the field test results are not consistent with laboratory standard tests, nor are they comparable;

2) The amount of smoke generated by lighting a cigarette or a smoker cannot be quantitatively controlled, and there is a lack of means to measure the smoke concentration at the project site, so it is impossible to make a quantitative judgment on whether the fire detector has achieved the corresponding fire detection response performance;

3) The detection method of lit cigarettes is extremely labor-intensive, and the detection efficiency is low, resulting in a huge workload of system engineering debugging, acceptance and maintenance.

The existence of the above problems directly leads to the inability to accurately judge the response degree of the fire alarm system to the fire signal at the scene, and it is impossible to accurately and objectively evaluate the real protection degree that the detection system can achieve in the scene. However, the method of sealing the samples of the detectors on site to a special testing agency for inspection lacks scientificity, rationality and operability.

SUMMARY OF THE INVENTION

Aiming at the problems existing in the prior art, the present invention provides a quantitative detection device and method for a point-type smoke detector.

In order to solve the above-mentioned technical problems, the technical scheme adopted by the present invention is:

In one aspect, the present invention provides a quantitative detection device for a point-type smoke detector, comprising a detection end, a control end and a tripod;

The detection end includes a reflector, a smoke collecting hood, a smoking flue, a smoking fan, a smoking module, a detection optical path cavity, a detection module, a two-way switch, a battery pack, an exhaust fan, and a smoke module air chamber. The battery compartment; the reflector is molded by a high-precision hexagonal mold core, and is installed directly above the detection optical path cavity in the fume collecting hood to reflect infrared light to form a small-sized optical path; the detection optical path cavity It is made of ferrous metal and is connected to the reflector and the detection module to detect the brightness attenuation of the light inside the closed cover; the smoke collecting cover is molded from a transparent acrylic material, and is arranged above the smoking flue and the detection light path cavity. , wrap the point-type smoke detector quantitative detection device in the smoke collecting hood to form a completely closed space; the detection module is installed directly below the detection optical path cavity, and is used to detect the change of the attenuation value on the optical path; The reflector and the detection module are installed perpendicular to the center line of the detection optical path cavity; the smoke-adding fan is installed just below the smoke-generating flue, and is used to pass the pre-mixed smoke from the smoke-generating module through The smoking flue is transported into the fume collecting hood; the smoking flue is made of ferrous metal, and the smoking module is arranged in the air chamber of the smoking module below the smoking fan; the battery pack is arranged at In the battery compartment, one side of the battery compartment is connected to the smoke generating module, the exhaust fan is arranged below the detection module, and is used to exhaust the smoke in the detection end; the two-way switch is arranged between the exhaust fan and the detection module, It is used for the control between the detection terminal circuit, the smoke module and the battery pack;

The smoke module is composed of a liquid storage chamber, a smoke heating device and a fan, the fan is installed in the lower part of the liquid storage chamber, the smoke heating device is installed in the upper part of the liquid storage chamber, and the liquid storage chamber passes through the oil-absorbing cotton and the smoke heating device connected;

The detection module is composed of a lenticular lens, a background infrared LED light-emitting tube, a detection infrared LED light-emitting tube, an infrared receiving tube, a signal processing light source driving circuit board, and a lens module; the lenticular lens is installed in the cavity of the lens module The bottom, parallel to the reflector, includes a first lens and a second lens, the first lens is used for converging and detecting the light reflected by the infrared LED light-emitting tube light source through the reflector and focusing on the infrared receiving tube, and the second lens is used for converging The infrared light emitted by the infrared LED light-emitting tube is detected; the lens module is fixed on the surface of the signal processing light source driving circuit board; the signal processing light source driving circuit board is embedded with a signal processing circuit and a photocell driving circuit, and the photocell driving circuit is respectively connected with the The signal processing circuit is connected with the infrared receiving tube, and the background infrared LED light-emitting tube, the detection infrared LED light-emitting tube and the infrared receiving tube are all welded on the surface of the signal processing light source driving circuit board; the infrared receiving tube is arranged on the first lens of the lens module The top of the cavity where it is located; the detection infrared LED light-emitting tube is arranged on the top of the cavity where the second lens of the lens module is located; the axis of the background infrared LED light-emitting tube and the infrared receiver tube is parallel to the cavity of the lens module, perpendicular to the lenticular lens, and the background infrared The light source emitted by the LED light-emitting tube is directly received by the infrared receiving tube.

The control terminal includes a control terminal casing, a control terminal circuit board, a liquid crystal display, a buzzer, a control button, a portable hook, a lanyard, a switch, and a charging hole. The control terminal circuit board is installed in the control terminal casing, so The liquid crystal display is installed on the control end circuit board to display the detection data and software functions; the buzzer and the control button are welded on the control end circuit board; the liquid crystal display, the buzzer and the control button are on the control end There are corresponding openings on the shell; the switch and the charging hole are fixed on the surface of the control end shell; the portable hook is fixed on the opposite side of the control end shell, and the lanyard is connected to the hook;

The buzzer is operated by pressing keys on the control end, and a prompt sound is output when the battery is low; the six keys of the control key are up, down, exit, confirm, stop and start respectively; the switch is used for the control end circuit Control with the battery pack; the charging hole is used to charge the battery at the control end.

The tripod is composed of a connecting piece, a tripod, and a supporting piece. The connecting piece is connected to the detection end through a bayonet, and the tripod is connected to the supporting piece through a bayonet to fix the supporting frame. The supporting frame is 5-stage telescopic. type, two adjacent sections are fixedly connected by bayonet;

On the other hand, a quantitative detection method for point-type smoke detectors is implemented by the aforementioned quantitative detection device for point-type smoke detectors: the method includes the following steps:

Step 1: Input smoke into the smoke detection area by controlling the smoke generating device, and create a simulated smoke environment in the detection area;

Step 2. Detect the smoke concentration in the detection area through the detection end of the quantitative detection device of the smoke detector and transmit the detection result to the control end from time to time;

Step 3: The detection ends when the quantitative detection device of the smoke detector generates an alarm action, and the smoke concentration corresponding to this moment is the on-site test response threshold of the point-type smoke detector.

The beneficial effects produced by the above technical solutions are:

The invention provides a quantitative detection device and method for a point-type smoke detector, which improves the inability of the traditional detection device to accurately judge the response degree of the fire alarm system to the fire signal on site, and the inability to accurately and objectively evaluate the detection system's performance in the field. The defects of the real protection degree that can be achieved in the occasion have the advantages of easy operation, short measurement period, high precision, easy portability, easy application and maintenance, and stable and reliable performance.

Description of drawings

1 is a schematic diagram of a quantitative detection device for a point-type smoke detector provided by an embodiment of the present invention;

2 is a schematic diagram of a detection terminal provided by an embodiment of the present invention;

In the figure, 1-reflector, 2-smoke hood, 3-smoke flue, 4-smoke fan, 5-smoke module, 6-detection light path cavity, 7-detection module, 8-dual-channel Switch, 9-battery pack, 10-exhaust fan;

3 is a schematic diagram of a detection module provided by an embodiment of the present invention;

In the figure, 11-first lens, 12-background infrared LED light-emitting tube, 13-infrared receiver tube, 14-signal processing circuit, 15-photoelectric cell drive circuit, 16-detection infrared LED light-emitting tube, 17-lens module, 18 - the second lens;

4 is a schematic diagram of a control terminal provided by an embodiment of the present invention;

In the figure, 19-LCD, 20-Buzzer, 21-Control button, 22-Portable hook, 23-Switch, 24-Charging hole;

Fig. 5 is the control flow chart of the lower computer provided by the embodiment of the present invention;

Fig. 6 is the control flow chart of the upper computer provided by the embodiment of the present invention;

FIG. 7 is a schematic block diagram of a detection terminal provided by an embodiment of the present invention;

8 is a schematic block diagram of a control terminal provided by an embodiment of the present invention;

FIG. 9 is a minimal system diagram of a detection terminal provided by an embodiment of the present invention;

FIG. 10 is a circuit diagram of a smoke control drive circuit at a detection end provided by an embodiment of the present invention;

FIG. 11 is a driving circuit diagram of a detection end infrared light emitting tube light source provided by an embodiment of the present invention;

12 is a circuit diagram of a detection terminal signal amplification circuit provided by an embodiment of the present invention;

13 is a minimal system diagram of a control terminal provided by an embodiment of the present invention;

FIG. 14 is a circuit diagram of a control terminal liquid crystal interface provided by an embodiment of the present invention;

15 is a circuit diagram of a control terminal 2.4G wireless communication interface provided by an embodiment of the present invention;

16 is a circuit diagram of a control terminal key module provided by an embodiment of the present invention;

FIG. 17 is a communication circuit diagram of a control terminal 485 according to an embodiment of the present invention.

Detailed ways

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In one aspect, the present invention provides a quantitative detection device for a point-type smoke detector, as shown in FIG. 1 , comprising a detection end, a control end and a tripod;

As shown in Figure 2, the detection end includes a reflector 1, a smoke collecting hood 2, a smoking flue 3, a smoking fan 4, a smoking module 5, a detection optical path cavity 6, a detection module 7, and a two-way switch 8. The battery pack 9, the exhaust fan 10, the air chamber of the smoke module, and the battery compartment; the reflector 1 is molded by a high-precision hexagonal mold core, and is installed in the smoke collecting hood 2 just above the detection optical path cavity , used to reflect infrared light to form a small-sized optical path; the detection optical path cavity 6 is made of ferrous metal, and is connected to the reflector 1 and the detection module 7 to detect the brightness attenuation of the light inside the closed cover; the smoke collection cover 2 is molded from a transparent acrylic material, and is arranged above the smoke flue 3 and the detection optical path cavity 6, and the quantitative detection device of the point-type smoke detector is wrapped in the smoke collecting hood 2 to form a completely closed space; The detection module 7 is installed directly below the detection optical path cavity 6, and is used to detect the change of the attenuation value on the optical path; the reflector 1 and the detection module 7 are installed perpendicular to the centerline of the detection optical path cavity 6; the The smoking fan 4 is installed directly below the smoking flue 3, and is used to transport the premixed smoke from the smoking module 5 into the fume collecting hood 2 through the smoking flue 3; The flue 3 is made of ferrous metal, and the smoking module 5 is arranged in the air chamber of the smoking module 5 below the smoking fan 4; the battery pack 9 is arranged in the battery compartment, and the side of the battery compartment is connected to the The smoke modules are connected, and the exhaust fan 10 is arranged below the detection module 7 to discharge the smoke in the detection end; the two-way switch 8 is arranged between the exhaust fan 10 and the detection module 7 for detection of the detection end The circuit in the module, the control between the smoking module 5 and the battery pack 9;

The smoke module is composed of a liquid storage chamber, a smoke heating device and a fan, the fan is installed in the lower part of the liquid storage chamber, the smoke heating device is installed in the upper part of the liquid storage chamber, and the liquid storage chamber passes through the oil-absorbing cotton and the smoke heating device connected;

As shown in Figure 3, the detection module is composed of a lenticular lens, a background infrared LED light-emitting tube 12, a detection infrared LED light-emitting tube 16, an infrared receiving tube 13, a signal processing light source driving circuit board, and a lens module 17; The convex lens is installed at the bottom of the cavity of the lens module 17, parallel to the reflector 1, and includes a first lens 11 and a second lens 18. The first lens 11 is used to converge and detect the infrared LED light-emitting tube 12. The light source passes through the reflector. 1. The reflected light is focused on the infrared receiving tube 13, and the second lens 18 is used to collect and detect the infrared light emitted by the infrared LED light-emitting tube; the lens module 17 is fixed on the surface of the signal processing light source driving circuit board; the signal processing light source A signal processing circuit 14 is embedded on the driving circuit board, which is used for amplifying the photoelectric signal, and a photocell driving circuit 15. The photocell driving circuit is respectively connected with the signal processing circuit 14 and the infrared receiving tube 13. According to the signal generated by the signal processing circuit 14 The control signal is used to drive the photocell to emit light; the background infrared LED light-emitting tube 12, the detection infrared LED light-emitting tube 16 and the infrared receiver tube 13 are all welded on the surface of the signal processing light source drive circuit board; the infrared receiver tube 13 is arranged on the lens mold. The top of the cavity where the first lens 11 of the group is located; the detection infrared LED light-emitting tube 16 is arranged on the top of the cavity where the second lens 18 of the lens module is located; the background infrared LED light-emitting tube 12, the axis of the infrared receiving tube 13 and the cavity of the lens module 17 The body is parallel and perpendicular to the lenticular lens, and the light source emitted by the background infrared LED light-emitting tube 12 is directly received by the infrared receiving tube 13, thereby providing the background light source;

As shown in Figure 4, the control terminal includes a control terminal shell, a control terminal circuit board, a liquid crystal display 19, a buzzer 20, a control button 21, a portable hook 22, a lanyard, a switch 23, and a charging hole 24. The control end circuit board is installed in the control end housing, and the liquid crystal display 19 is installed on the control end circuit board for displaying detection data and software functions; the buzzer 20 and the control button 21 are welded on the control end circuit board ; Described liquid crystal display 19, buzzer 20, control button all have corresponding openings on the control end casing; switch 23 and charging hole 24 are fixed on the control end casing surface; The portable hook 22 is fixed on the control end casing At the opposite side of the body, the lanyard is connected to the hook 22;

The buzzer 20 is operated by pressing the keys on the control end, and a prompt sound is output when the battery power is low; the six buttons of the control button 21 are up, down, exit, confirm, stop and start respectively; the switch 23 is used for Control between the control terminal circuit and the battery pack; the charging hole 24 is used for charging the control terminal battery.

The tripod is composed of a connecting piece, a tripod, and a supporting piece. The connecting piece is connected to the detection end through a bayonet, and the tripod is connected to the supporting piece through a bayonet to fix the supporting frame. The supporting frame is 5-stage telescopic. type, two adjacent sections are fixedly connected by bayonet;

On the other hand, a quantitative detection method for point-type smoke detectors is implemented by the aforementioned quantitative detection device for point-type smoke detectors: the method includes the following steps:

Step 1: Input smoke into the smoke detection area by controlling the smoke generating device, and create a simulated smoke environment in the detection area;

Step 2. Detect the smoke concentration in the detection area through the detection end of the quantitative detection device of the smoke detector and transmit the detection result to the control end from time to time;

Step 3: The detection ends when the quantitative detection device of the smoke detector generates an alarm action, and the smoke concentration corresponding to this moment is the on-site test response threshold of the point-type smoke detector.

The detection end circuit of the quantitative detection device of the point-type smoke detector consists of a light source driving module that generates a driving signal to control the infrared light-emitting tube, a smoke control module that controls the amount of smoke, a photoelectric conversion sampling module that collects smoke concentration, and a wireless data transmission module capable of data transmission. It consists of a communication module and a main control module. The minimum system diagram of the detection end in this embodiment is shown in Figure 9. The smoke drive control circuit includes a first MOS transistor T1, a second MOS transistor T1_1, a third MOS transistor T2, and a fourth MOS transistor. T2_1; wherein: the drains of the first MOS tube and the second MOS tube are respectively connected to the positive poles of the smoking fan and the exhaust fan, and the drains of the third MOS tube and the fourth MOS tube are respectively connected to the heating wire of the smoking module It is connected to the positive pole of the fan, and the gates of the four MOS tubes are connected to the smoke drive module. The smoke control drive circuit uses PWM control to control the turn-on and turn-off of the first MOS transistor T1, the third MOS transistor T2 and the fourth MOS transistor T2_1, and dynamically adjust the MOS transistors T2 and T2_1 by detecting the rising rate of the smoke concentration. On-time, control the smoke output of the smoking module and the speed of the fan, and achieve a constant rising rate of smoke concentration. After the detection, the smoke adding fan and exhaust fan are fully opened, and the smoke exhaust cleaning of the optical path cavity is carried out. Each MOS tube is Model SI2315 is used.

The light source drive circuit is divided into the main emission tube D4 and the slave emission tube D7 by selecting an infrared light-emitting tube with a wavelength of 940nm with a wide operating temperature range, and cooperates with the constant current source drive circuit built by LM317, analog switch 4066 and realize the light-emitting tube. Stable control of working current.

Photoelectric conversion sampling circuit, in order to achieve accurate detection of small light intensity attenuation, the amplifier circuit firstly amplifies and converts the current signal output by infrared receiving S1 into a voltage signal through a cross-group amplification design composed of U2C, R32, and C4. Through the strobe of the analog switch 4066, the integral op amp is partially amplified. During actual operation, in order to eliminate the change of the photosensitive signal with the difference of the ambient light intensity, the INA326 and The differential amplifying circuit composed of peripheral circuits makes the signal amplifying output not affected by the intensity of ambient light.

A complete optical path driving cycle consists of 8 stages:

Stage (1) The fourth channel of the analog switch 4066 is turned on, the capacitor E13 corresponding to the main transmitting tube D4 is charged, the fourth channel of the analog switch 4066 is turned off, and the charging is completed.

Stage (2) The first channel of the analog switch 4066 is turned on, the transistor Q3 is turned on, the corresponding capacitor E13 of the main transmitting tube is discharged, the main transmitting tube D4 emits an infrared beam, the first channel of the analog switch 4066 is turned off, the transistor Q3 is turned off, and the discharge is over .

Stage (3) The third channel of the analog switch 4066 is turned on, and the capacitor E14 corresponding to the transmitting tube D7 is charged, and the third channel of the analog switch is turned off, and the charging is completed.

Stage (4) The second channel of the analog switch 4066 is turned on, the transistor Q7 is turned on, the corresponding capacitor E14 is discharged from the transmitting tube D7, the infrared beam is emitted from the transmitting tube D7, the second channel of the analog switch 4066 is turned off, the transistor Q7 is turned off, and the discharge is Finish.

Stage (5) The third channel of the analog switch 4066 is turned on, and the capacitor E14 corresponding to the transmitting tube D7 is charged, and the third channel of the analog switch is turned off, and the charging is completed.

Stage (6) The second channel of the analog switch 4066 is turned on, the transistor Q7 is turned on, the corresponding capacitor E14 is discharged from the transmitting tube D7, the infrared beam is emitted from the transmitting tube D7, the second channel of the analog switch 4066 is turned off, the transistor Q7 is turned off, and the discharge is Finish.

Stage (7) The fourth channel of the analog switch 4066 is turned on, the capacitor E13 corresponding to the main transmitting tube D4 is charged, the fourth channel of the analog switch 4066 is turned off, and the charging is completed.

Stage (8) The first channel of the analog switch 4066 is turned on, the transistor Q3 is turned on, the corresponding capacitor E13 of the main transmitting tube is discharged, the main transmitting tube D4 emits an infrared beam, the first channel of the analog switch 4066 is turned off, the transistor Q3 is turned off, and the discharge is over . A complete optical path drive cycle is completed.

Further, as shown in Figure 7, the main control unit of the detection end has an ARM chip STM32 with multiple interfaces. One end of the chip is connected to the driver module, and the other end is connected to the photoelectric conversion and sampling circuit, which is used to drive the cigarette according to the sampling value. device, and peripheral circuits used to support the normal operation of the ARM chip. The smoke control drive circuit at the detection end is shown in Figure 10, the infrared light source drive circuit at the detection end is shown in Figure 11, and the signal amplification circuit at the detection end is shown in Figure 12.

The control terminal circuit of the quantitative detection device of the point-type smoke detector is shown in Figure 8. It consists of a main control module, a liquid crystal module, a wireless transmission module, a key module, and a 485 communication module. The minimum system diagram of the control terminal is shown in Figure 13. , the LCD interface circuit of the control terminal is shown in Figure 14, the 2.4G wireless communication interface circuit of the control terminal is shown in Figure 15, the button module circuit is shown in Figure 16, and the 485 communication circuit of the control terminal is shown in Figure 17.

The main control unit consists of STM32 and peripheral circuits that support its normal operation. The key module and liquid crystal module are used for human-computer interaction with STM32, and are used to issue detection, stop, cleaning, read address commands, and display the smoke uploaded by the detection terminal. Concentration value, battery voltage information, etc. The 485 communication circuit adopts the 3485 chip, which is used for communication with the host computer software such as the computer.

The wireless communication between the detection terminal and the control terminal adopts the wireless serial port LC12S module to realize the data and command transmission between the control terminal and the detection section.

As shown in Figure 6, after the upper computer detects that the "start" key is pressed, it downloads the "start detection command" to the lower computer wirelessly. After the initialization is completed, the smoke value is uploaded at an interval of 1s, and it stops after receiving the "stop detection command".

If the upper computer downloads the "start detection command" three times in a row, and does not receive the feedback from the lower computer, it will display "command sending failure". After receiving the feedback command from the lower computer, it starts counting every second and displays the accumulated time. If the smoke value is verified correctly, the received smoke value data will be displayed on the LCD screen.

If the upper computer detects that the "stop" key is pressed, it will download the "stop detection command" to the lower computer wirelessly. Complete this test.

As shown in Figure 5, after receiving the detection command from the upper computer, the lower computer starts to perform AD acquisition and conversion on the voltage output value of the photoelectric conversion differential sampling circuit, and the AD value represents the attenuation degree of smoke to light. If the AD value is too large, it means that the ambient light is not accurately offset in the photoelectric conversion differential sampling circuit, and runtime calibration is required.

The run-time calibration process is as follows: fine-tune the charging time of the charging capacitor E14, and record the AD value of the photoelectric conversion differential sampling circuit. When the AD value is less than a certain amount (for example, less than 300 under the 12-bit sampling width), the run-time calibration is completed.

After the runtime calibration is completed, the AD values are averaged 3s to 10s before the acquisition, and the average value is used as the background value ADb of the light attenuation in the smoke-free state. Then take 500ms～1000ms as a cycle, collect the AD value periodically, and use the difference between AD value and ADb as the light attenuation ADt caused by smoke, and start the smoke control drive circuit to drive the smoke module to generate smoke. , and start the smoking fan to start the smoke circulation. In the detection process, according to the ADt size and the rising rate, the average output voltage of the smoke control drive circuit is controlled in sections, and then the heating power of the smoke generating module is controlled to control the amount of smoke, and the average output of the smoke control drive circuit is controlled. The voltage decreases slightly in the middle and later stages of smoking, which can keep the smoke concentration ADt increasing in a linear manner.

The relationship between the light attenuation ADt and the smoke concentration (dB/m) is achieved by calibrating with an optical smoke densitometer in a standard smoke box. The specific method is: place the lower computer in the standard smoke box, The smoke box is linearly raised at a constant rate, and the corresponding point between ADt and smoke concentration is calibrated at every calibration interval of 0.05dB/m. During detection, the smoke concentration value corresponding to the non-calibration point ADt is calculated by linear interpolation.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope defined by the claims of the present invention .

Claims (4)

1. A point-type smoke detector quantitative detection device, characterized in that: comprising a detection end, a control end and a tripod; The detection end includes a reflector, a smoke collecting hood, a smoking flue, a smoking fan, a smoking module, a detection optical path cavity, a detection module, a two-way switch, a battery pack, an exhaust fan, and a smoke module air chamber. The battery compartment; the reflector is molded by a high-precision hexagonal mold core, and is installed directly above the detection optical path cavity in the fume collecting hood; the detection optical path cavity is made of ferrous metal and is connected to the reflector and the detection module The smoke collecting hood is molded from transparent acrylic material, and is arranged above the smoking flue and the detection optical path cavity, and the quantitative detection device of the point-type smoke detector is wrapped in the smoke collecting hood to form a completely enclosed space The detection module is installed directly below the detection optical path cavity, and the reflector and the detection module are both installed vertically with the centerline of the detection optical path cavity; the smoking fan is installed directly below the smoke duct, The smoking flue is made of black metal material, and the smoking module is arranged in the air chamber of the smoking module below the smoking fan; The modules are connected, the exhaust fan is arranged below the detection module, and the two-way switch is arranged between the exhaust fan and the detection module; The control terminal includes a control terminal casing, a control terminal circuit board, a liquid crystal display, a buzzer, a control button, a portable hook, a lanyard, a switch, and a charging hole, and the control terminal circuit board is installed in the control terminal casing. , the liquid crystal display is installed on the control end circuit board to display the detection data and software functions; the buzzer and the control button are welded on the control end circuit board, the buzzer is operated on the control end button, and the battery power is low The prompt tone is output when the status is in, and the six control buttons are up, down, exit, confirm, stop and start respectively; the liquid crystal display, buzzer and control buttons have corresponding openings on the control end shell; the switch and the charging hole is fixed on the surface of the control end shell, and the switch is used for control between the control end circuit and the battery pack; the charging hole is used for charging the control end battery; the portable hook is fixed on the opposite side of the control end shell , the lanyard is connected to the hook; The tripod is composed of a connecting piece, a tripod, and a supporting piece. The connecting piece is connected to the detection end through a bayonet, and the tripod is connected to the supporting piece through a bayonet to fix the supporting frame. The supporting frame is 5-stage telescopic. Type, two adjacent sections are fixedly connected by bayonet. 2 . The quantitative detection device for a point-type smoke detector according to claim 1 , wherein the smoke generating module is composed of a liquid storage chamber, a smoke heating device and a fan, and the fan is installed with the fan. 3 . In the lower part of the liquid storage chamber, the smoke heating device is installed on the upper part of the liquid storage chamber, and the liquid storage chamber is connected with the smoke heating device through oil-absorbing cotton. 3. The quantitative detection device for a point-type smoke detector according to claim 1, wherein the detection module is composed of a lenticular lens, a background infrared LED light-emitting tube, a detection infrared LED light-emitting tube, and an infrared receiving tube. , a signal processing light source drive circuit board, and a lens module; the biconvex lens is installed at the bottom of the lens module cavity, parallel to the reflector, and includes a first lens and a second lens, and the first lens is used for The light reflected by the light source of the infrared LED light-emitting tube is focused on the infrared receiving tube by the reflector, and the second lens is used for converging and detecting the infrared light emitted by the infrared LED light-emitting tube; the lens module is fixed on the surface of the signal processing light source driving circuit board The signal processing light source driving circuit board is embedded with a signal processing circuit and a photoelectric tube driving circuit, and the photoelectric tube driving circuit is respectively connected with the signal processing circuit and the infrared receiving tube. The background infrared LED light-emitting tube, the detection infrared LED light-emitting tube and the infrared light-emitting tube are The receiving tubes are all welded on the surface of the signal processing light source drive circuit board; the infrared receiving tubes are arranged on the top of the cavity where the first lens of the lens module is located; the detection infrared LED light-emitting tube is arranged on the top of the cavity where the second lens of the lens module is located ; The axis of the background infrared LED light-emitting tube and the infrared receiving tube is parallel to the cavity of the lens module and perpendicular to the lenticular lens, and the light source emitted by the background infrared LED light-emitting tube is directly received by the infrared receiving tube. 4. A quantitative detection method for a point-type smoke detector, comprising the following steps: a quantitative detection device for a point-type smoke detector according to claim 1, characterized in that: Step 1: Input smoke into the smoke detection area by controlling the smoke generating device, and create a simulated smoke environment in the detection area; Step 2. Detect the smoke concentration in the detection area through the detection end of the quantitative detection device of the smoke detector and transmit the detection result to the control end from time to time; Step 3: The detection ends when the quantitative detection device of the smoke detector generates an alarm action, and the smoke concentration corresponding to this moment is the on-site test response threshold of the point-type smoke detector.

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