A high speed chlorine detector

Abstract

The application relates to the field of gas detection, in particular to a high-speed chlorine gas detector. The high-speed chlorine gas detector comprises a chlorine gas sensing module, a signal conversion module, a control module and a display module. The chlorine gas sensing module is connected with the signal conversion module through an operational amplifier module, and the operational amplifier module is used for amplifying the analog signal generated by the chlorine gas sensing module and then sending the analog signal to the signal conversion module. The operational amplifier module contains an operational amplifier, the output end of the operational amplifier is connected with the inverting input end of the operational amplifier through a negative feedback resistor, the slope of the operational amplifier is changed by using the negative feedback resistor, and the detection speed is improved.

Description

Technical Field

[0001] This invention relates to the field of gas detection, specifically a high-speed chlorine gas detector. Background Technology

[0002] Currently, traditional chlorine detectors include a chlorine sensing module, a signal conversion module, a control module, and a display module. The chlorine sensing module is connected to the signal conversion module, which in turn is connected to the control module, and the control module is connected to the display module. The chlorine sensing module detects the concentration of chlorine in the environment and converts this concentration information into an analog signal, which is then sent to the signal conversion module. The signal conversion module converts the analog signal into a digital signal and sends it to the control module. The control module then uses the digital signal to control the display module to show the chlorine concentration information. Traditional chlorine detectors directly transmit the analog signal to the signal conversion module, resulting in a weak signal and slow response time. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a high-speed chlorine gas detector with strong signal and fast response speed.

[0004] To address the aforementioned problems, the following technical solution is provided: The high-speed chlorine detector of the present invention includes a chlorine sensing module, a signal conversion module, a control module, and a display module. The chlorine sensing module is adapted and connected to the signal conversion module, the signal conversion module is adapted and connected to the control module, and the control module is adapted and connected to the display module. The chlorine sensing module detects the concentration of chlorine in the environment and converts the chlorine concentration information into an analog signal, which is then sent to the signal conversion module. The signal conversion module converts the analog signal into a digital signal and sends it to the control module. The control module controls the display module to display the chlorine concentration information based on the digital signal. A key feature is that the chlorine sensing module is connected to the signal conversion module via an operational amplifier module. The operational amplifier module amplifies the analog signal generated by the chlorine sensing module and sends it to the signal conversion module. The operational amplifier module contains an operational amplifier, and the output terminal of the operational amplifier is connected to the inverting input terminal of the operational amplifier through a negative feedback resistor. The negative feedback resistor is used to change the voltage gain slope of the operational amplifier, thereby improving the detection speed.

[0005] The chlorine sensing module contains a sensor, and there is an IV conversion circuit between the CE and RE pins of the sensor. When chlorine enters the sensor, the sensor generates a current signal. The IV conversion circuit converts the current signal into a voltage signal, forms the analog signal, and transmits it to the operational amplifier module.

[0006] The sensor is an alcohol-resistant sensor.

[0007] The IV conversion circuit includes a reference voltage chip U02 and a transistor Q02; the VIN pin of the reference voltage chip U02 is connected to the first power supply and one end of the capacitor C13, and the other end of the capacitor C13 is grounded; the GND pin of the reference voltage chip U02 is grounded; the VOUT pin of the reference voltage chip U02 is connected to the non-inverting input of the operational amplifier U03A, the output of the operational amplifier U03A is connected to one end of the resistor R03, and the other end of the resistor R03 is connected to the CE pin of the sensor. The RE pin of the sensor is connected to one end of resistor R04 and the drain (D) of transistor Q02. The other end of resistor R04 is connected to one end of capacitor C16 and resistor R02. The other end of capacitor C16 is connected to the output of operational amplifier U03A. The other end of resistor R02 is connected to capacitor C15 and the inverting input of operational amplifier U03A. The other end of capacitor C15 is connected to the output of operational amplifier U03A. The gate (G) of transistor Q02 is connected to the first power supply through resistor R05. The source (S) of transistor Q02 is connected to the WE pin of the sensor.

[0008] The operational amplifier module includes operational amplifiers U03B and U04. The source (S) terminal of transistor Q02 is connected to one end of resistor R06, and the other end of resistor R06 is connected to the inverting input of operational amplifier U03B. The non-inverting input of operational amplifier U03B is connected to a second power supply. The output of operational amplifier U03B is connected to one end of resistors R07 and R08, respectively. The other end of resistor R07 is connected to the inverting input of operational amplifier U03B. Resistor R07 serves as the negative feedback resistor for operational amplifier U03B. A capacitor C17 is connected in parallel across resistor R07. The other end of resistor R08 is connected to capacitor C19 and operational amplifier U04, respectively. The other end of capacitor C19 is grounded. Operational amplifier U03B amplifies the analog signal at one stage and then transmits it to operational amplifier U04 through resistor R08. Operational amplifier U04 amplifies the amplified analog signal at one stage and then transmits it to the conversion module.

[0009] One end of resistor R08, connected to capacitor C19, is connected to one end of resistor R12. The other end of resistor R12 is connected to one end of resistor R15. The other end of resistor R15 is connected to the inverting input of operational amplifier U04. The second power supply is connected to one end of resistor R09. The other end of resistor R09 is connected to one end of resistor R10, capacitor C20, resistor R13, and resistor R14. The other ends of resistor R10 and capacitor C20 are grounded. The other end of resistor R13 is connected to one end of resistor R16. The other end of resistor R14 is connected to the connection point of resistors R12 and R15. The other end of resistor R16 is connected to the non-inverting input of operational amplifier U04 and one end of resistor R18. The other end of resistor R18 is grounded. The connection point of resistor R08 and resistor R11 is connected to one end of resistor R11. The other end of resistor R11 is connected to the connection point of resistors R13 and R16. The inverting input terminal of the operational amplifier U04 is connected to one end of capacitor C21 and resistor R19, respectively. The other end of capacitor C21 is connected to the inverting input terminal of operational amplifier U04. The other end of resistor R19 is connected to one end of inductor L02, resistor R17 and capacitor C23, respectively. The other end of resistor R17 is connected to the inverting input terminal of operational amplifier U04. The other end of inductor L02 is connected to one end of the conversion module and capacitor C24, respectively. The other ends of capacitors C23 and C24 are grounded.

[0010] The control module is adapted to be connected to an infrared receiver.

[0011] The above approach has the following advantages:

[0012] Because the chlorine sensing module of the high-speed chlorine detector of this invention is connected to the signal conversion module via an operational amplifier module, the operational amplifier module amplifies the analog signal generated by the chlorine sensing module and sends it to the signal conversion module. The operational amplifier module contains an operational amplifier, and the output terminal of the operational amplifier is connected to the inverting input terminal of the operational amplifier through a negative feedback resistor. By using the negative feedback resistor to change the voltage gain slope of the operational amplifier, the detection speed is improved. This detector uses an operational amplifier module to amplify the analog signal and then uses a negative feedback resistor to change the voltage gain slope of the operational amplifier, thereby improving the signal transmission speed and shortening the detection time. Attached Figure Description

[0013] Figure 1 This is a circuit block diagram of the high-speed chlorine gas detector of the present invention;

[0014] Figure 2A This is a circuit diagram of the first half of the operational amplifier module in the high-speed chlorine detector of the present invention;

[0015] Figure 2BThis is a circuit diagram of the latter half of the operational amplifier module in the high-speed chlorine detector of the present invention.

[0016] Figure 3 This is a circuit diagram of the control module in the high-speed chlorine detector of the present invention;

[0017] Figure 4 This is a circuit diagram of the display module in the high-speed chlorine detector of the present invention;

[0018] Figure 5 This is a circuit diagram of the infrared receiver tube in the high-speed chlorine detector of the present invention;

[0019] in, Figure 2A R06 and Figure 2B R06 in the text refers to the same component. Detailed Implementation

[0020] The following is in conjunction with the appendix Figure 1-5 The present invention will be described in further detail below.

[0021] like Figure 1 As shown, the high-speed chlorine detector of the present invention includes a chlorine sensing module, a signal conversion module, a control module, a display module, and an infrared receiver. The chlorine sensing module is connected to the signal conversion module via an operational amplifier module. The signal conversion module is adapted to the control module, and the control module is adapted to the display module and the infrared receiver. The chlorine sensing module detects the concentration of chlorine in the environment and converts the concentration information into an analog signal, which is then sent to the operational amplifier module. The operational amplifier module amplifies the analog signal generated by the chlorine sensing module and sends it to the signal conversion module. The signal conversion module converts the analog signal into a digital signal and sends it to the control module. The control module controls the display module to display the chlorine concentration information based on the digital signal. The infrared receiver receives infrared control signals, thereby enabling remote control functionality.

[0022] In this embodiment, the signal conversion module is an AD digital-to-analog converter, and its specific circuit structure is common knowledge and will not be described in detail here. The display module is an LCD display, and its peripheral circuit is as follows: Figure 4 As shown, this is existing technology and will not be elaborated further here.

[0023] In this embodiment, the control module contains a 90C514RD+ microcontroller, which is connected to peripheral circuits for driving its operation, such as... Figure 3 As shown, this is existing technology and will not be elaborated further here.

[0024] In this embodiment, the control module is adapted to connect to a DA digital-to-analog converter and a 4-20mA output for outputting a 4-20mA analog signal. The specific circuit structure of the DA digital-to-analog converter and the 4-20mA output, as well as their connection method with the microcontroller, are existing technologies and will not be described in detail here.

[0025] In this embodiment, the circuit of the infrared receiver is as follows: Figure 5 As shown, the circuit structure is existing technology and will not be described in detail here.

[0026] like Figure 2A As shown, the chlorine sensing module contains a sensor, which is an alcohol-resistant sensor to achieve the function of resisting alcohol interference. In this embodiment, the sensor is a CL2 sensor manufactured by RIKEN in Japan.

[0027] like Figure 2A As shown, there is an IV conversion circuit between the CE and RE pins of the sensor. When chlorine gas enters the sensor, the sensor generates a current signal. The IV conversion circuit converts the current signal into a voltage signal, forms an analog signal, and transmits it to the operational amplifier module.

[0028] like Figure 2A As shown, the IV conversion circuit includes a reference voltage chip U02 and a transistor Q02. The VIN pin of the reference voltage chip U02 is connected to the first power supply and one end of capacitor C13, while the other end of capacitor C13 is grounded. The GND pin of the reference voltage chip U02 is grounded. The VOUT pin of the reference voltage chip U02 is connected to the non-inverting input of operational amplifier U03A. The output of operational amplifier U03A is connected to one end of resistor R03, and the other end of resistor R03 is connected to the CE pin of the sensor. The RE pin of the sensor is connected to one end of resistor R04 and the drain of transistor Q02. The other end of resistor R04 is connected to one end of capacitor C16 and one end of resistor R02. The other end of capacitor C16 is connected to the output of operational amplifier U03A. The other end of resistor R02 is connected to one end of capacitor C15 and the inverting input of operational amplifier U03A. The other end of capacitor C15 is connected to the output of operational amplifier U03A. The gate (G) of transistor Q02 is connected to the first power supply through resistor R05, and the source (S) of transistor Q02 is connected to the W / E pin of the sensor. When the sensor comes into contact with chlorine gas, it generates a current signal. This current signal is converted into a voltage signal by an operational amplifier U03A, a resistor-capacitor network consisting of resistors R03 and R02, capacitors C15 and C16, and transistor Q01, thus forming an analog signal.

[0029] like Figure 2BAs shown, the operational amplifier module contains operational amplifiers. The output of the operational amplifier is connected to its inverting input via a negative feedback resistor. This negative feedback resistor alters the voltage gain slope of the operational amplifier, improving detection speed. The operational amplifier module contains operational amplifiers U03B and U04. The source (S) of transistor Q02 is connected to one end of resistor R06, and the other end of resistor R06 is connected to the inverting input of operational amplifier U03B. The non-inverting input of operational amplifier U03B is connected to a second power supply. The output of operational amplifier U03B is connected to one end of resistors R07 and R08, respectively. The other end of resistor R07 is connected to the inverting input of operational amplifier U03B. Resistor R07 serves as the negative feedback resistor for operational amplifier U03B, and capacitor C17 is connected in parallel across resistor R07. The other end of resistor R08 is connected to capacitor C19 and operational amplifier U04 respectively. The other end of capacitor C19 is grounded. Operational amplifier U03B amplifies the analog signal in one stage and then transmits it to operational amplifier U04 through resistor R08. Operational amplifier U04 amplifies the analog signal in one stage in another stage and then transmits it to the conversion module. The analog signal sampling resistor R06, operational amplifier U03B, capacitor C17, and resistor R07 perform the first stage amplification, forming the first stage amplified signal after amplification by a factor of 330.

[0030] like Figure 2BAs shown, one end of resistor R08, connected to capacitor C19, is connected to one end of resistor R12. The other end of resistor R12 is connected to one end of resistor R15. The other end of resistor R15 is connected to the inverting input of operational amplifier U04. The second power supply is connected to one end of resistor R09. The other end of resistor R09 is connected to one end of resistor R10, capacitor C20, resistor R13, and resistor R14 respectively. The other ends of resistor R10 and capacitor C20 are both grounded. The other end of resistor R13 is connected to one end of resistor R16. The other end of resistor R14 is connected to the connection point of resistors R12 and R15. The other end of resistor R16 is connected to the non-inverting input of operational amplifier U04 and one end of resistor R18 respectively. The other end of resistor R18 is grounded. The connection point of resistor R08 and resistor R11 is connected to one end of resistor R11. The other end of resistor R11 is connected to the connection point of resistors R13 and R16. The inverting input of operational amplifier U04 is connected to one end of capacitor C21 and resistor R19, respectively. The other end of capacitor C21 is connected to the inverting input of operational amplifier U04. The other end of resistor R19 is connected to one end of inductor L02, resistor R17, and capacitor C23, respectively. The other end of resistor R17 is connected to the inverting input of operational amplifier U04. The other end of inductor L02 is connected to the conversion module and one end of capacitor C24, respectively. The other ends of capacitors C23 and C24 are grounded. The first-stage amplified signal then passes through resistor R08, polarity selection circuit, 0.4VDC reference circuit, resistor R15 or resistor R16, operational amplifier U04, resistor R17, and capacitor C21 for a second-stage amplification, with a magnification factor of 5. The analog signal, consisting of a 0.4-2.0VDC voltage, is then transmitted to the conversion module via resistor R19 and inductor L02.

[0031] In this embodiment, the first power supply is a 5V power supply, and the second power supply is a 1.25V power supply. Resistors R11, R12, R13, and R14 form a polarity selection circuit. The 1.25V power supply forms a 0.4VDC reference circuit through resistors R09, R13, and R14.

[0032] The high-speed chlorine detector of this invention requires calibration using standard gases. Calibration requires zero-point gas, 0.8 ppm CL2 / Air standard gas, an electronic stopwatch, and an EVT-100 infrared remote control. The calibration process is as follows:

[0033] The first step is to place the high-speed chlorine detector in a contaminant-free test chamber, preheat it for 30 seconds, and then introduce zero-point gas for 30 seconds to complete the zero-point calibration.

[0034] The second step involves introducing 0.8 ppm CL2 / Air standard gas into the sensor inlet at a rate of 0.5 liters per minute. Once the display stabilizes, the control module is operated to complete the calibration, and the actual measured result is 0.79 ppm.

[0035] Third, the high-speed chlorine detector read 0.00 ppm, and 0.8 ppm of CL2 / Air standard gas was introduced again. At the same time, a stopwatch was started to record the T90 response time. This process was repeated 3 times, and the average of the 3 times was taken as the T90 response time. The measured result was 21.43 s.

[0036] Third, the high-speed chlorine detector read 0.00 ppm, and 0.8 ppm of CL2 / Air standard gas was introduced, and the reading was recorded. This process was repeated six times, and the repeatability was measured at 1.1%.

[0037] Anti-interference alcohol test A: When 400ppm ethanol / Air standard gas is introduced into the chlorine sensor port, the high-speed chlorine detector of this invention displays a reading of 0.01ppm.

[0038] Anti-interference alcohol test B: Place a bottle of 99.9% pure alcohol 1 cm below the chlorine sensor port, open the cap, and allow the pure alcohol to evaporate for more than 30 seconds. The high-speed chlorine detector of this invention will display a reading of 0.00 ppm.

[0039] Anti-interference alcohol test C: When 1200ppm isopropanol / Air standard gas is introduced into the chlorine sensor port for 1 minute, the display reading of the high-speed chlorine detector of the present invention is 0.00ppm.

[0040] Anti-interference alcohol test D: When 1200ppm isopropanol / Air standard gas is introduced into the chlorine sensor port for 1 minute, the display reading of the high-speed chlorine detector of this invention is 0.00ppm.

[0041] The high-speed chlorine detector of this invention employs an alcohol-resistant gas sensor, providing 100% immunity to alcohol interference. Furthermore, the minimum sensing sensitivity of this high-speed chlorine detector is 0.01 ppm, the concentration display error is as low as 2% F.S., and the T90 response time is reduced by 12 seconds. The improved response speed is achieved through negative feedback from the operational amplifier U04.

Claims

1. A high-speed chlorine gas detector, comprising a chlorine gas sensing module, a signal conversion module, a control module, and a display module; wherein the chlorine gas sensing module is adapted and connected to the signal conversion module, the signal conversion module is adapted and connected to the control module, and the control module is adapted and connected to the display module; the chlorine gas sensing module is used to detect the concentration of chlorine gas in the environment and convert the chlorine gas concentration information into an analog signal and send it to the signal conversion module; the signal conversion module converts the analog signal into a digital signal and sends it to the control module; the control module controls the display module to display the chlorine gas concentration information according to the digital signal; characterized in that, The chlorine sensing module is connected to the signal conversion module via an operational amplifier module. The operational amplifier module amplifies the analog signal generated by the chlorine sensing module and sends it to the signal conversion module. The operational amplifier module contains an operational amplifier, the output of which is connected to the inverting input of the operational amplifier via a negative feedback resistor. This negative feedback resistor alters the voltage gain slope of the operational amplifier, improving the detection speed. The chlorine sensing module also contains a sensor. An IV-to-Voltage (IV-V) conversion circuit is located between the CE and RE pins of the sensor. When chlorine enters the sensor, it generates a current signal. The IV-Voltage (IV-V) conversion circuit converts this current signal into a voltage signal, forming the analog signal that is then transmitted to the operational amplifier module. The IV-Voltage (IV-V) conversion circuit includes a reference voltage chip U02 and a transistor Q02. The VIN pin of the reference voltage chip U02 is connected to a first power supply and one end of a capacitor C13, while the other end of the capacitor C13... Grounded; the GND pin of the reference voltage chip U02 is grounded; the VOUT pin of the reference voltage chip U02 is connected to the non-inverting input of the operational amplifier U03A, the output of the operational amplifier U03A is connected to one end of the resistor R03, and the other end of the resistor R03 is connected to the CE pin of the sensor; the RE pin of the sensor is connected to one end of the resistor R04 and the drain of the transistor Q02, the other end of the resistor R04 is connected to one end of the capacitor C16 and the resistor R02, the other end of the capacitor C16 is connected to the output of the operational amplifier U03A, the other end of the resistor R02 is connected to the capacitor C15 and the inverting input of the operational amplifier U03A, and the other end of the capacitor C15 is connected to the output of the operational amplifier U03A; the gate of the transistor Q02 is connected to the first power supply through the resistor R05, and the source of the transistor Q02 is connected to the WE pin of the sensor.

2. The high-speed chlorine detector as described in claim 1, characterized in that, The sensor is an alcohol-resistant sensor.

3. The high-speed chlorine detector as described in claim 1, characterized in that, The operational amplifier module includes operational amplifiers U03B and U04. The source (S) terminal of transistor Q02 is connected to one end of resistor R06, and the other end of resistor R06 is connected to the inverting input terminal of operational amplifier U03B. The non-inverting input terminal of operational amplifier U03B is connected to a second power supply. The output terminal of operational amplifier U03B is connected to one end of resistors R07 and R08, respectively. The other end of resistor R07 is connected to the inverting input terminal of operational amplifier U03B. Resistor R07 serves as the negative feedback resistor for operational amplifier U03B. A capacitor C17 is connected in parallel across resistor R07. The other end of resistor R08 is connected to capacitor C19 and operational amplifier U04, respectively. The other end of capacitor C19 is grounded. Operational amplifier U03B amplifies the analog signal at one stage and then transmits it to operational amplifier U04 through resistor R08. Operational amplifier U04 amplifies the amplified analog signal at one stage and then transmits it to the signal conversion module.

4. The high-speed chlorine detector as described in claim 3, characterized in that, One end of resistor R08, connected to capacitor C19, is connected to one end of resistor R12. The other end of resistor R12 is connected to one end of resistor R15. The other end of resistor R15 is connected to the inverting input of operational amplifier U04. The second power supply is connected to one end of resistor R09. The other end of resistor R09 is connected to one end of resistor R10, capacitor C20, resistor R13, and resistor R14. The other ends of resistor R10 and capacitor C20 are both grounded. The other end of resistor R13 is connected to one end of resistor R16. The other end of resistor R14 is connected to the connection point of resistors R12 and R15. The other end of resistor R16 is connected to the non-inverting input of operational amplifier U04 and one end of resistor R18. The other end of resistor R18 is grounded; the connection point of resistor R08 and resistor R11 is connected to one end of resistor R11, and the other end of resistor R11 is connected to the connection point of resistors R13 and R16; the inverting input of operational amplifier U04 is connected to one end of capacitor C21 and resistor R19 respectively, the other end of capacitor C21 is connected to the inverting input of operational amplifier U04, the other end of resistor R19 is connected to one end of inductor L02, resistor R17 and capacitor C23 respectively, the other end of resistor R17 is connected to the inverting input of operational amplifier U04, the other end of inductor L02 is connected to one end of the conversion module and capacitor C24 respectively, and the other ends of capacitors C23 and C24 are grounded.

5. The high-speed chlorine detector as described in claim 1, characterized in that, The control module is adapted to be connected to an infrared receiver.

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