CN113092435A - Fluorescence method dissolved oxygen measuring circuit and dissolved oxygen measuring device - Google Patents
Fluorescence method dissolved oxygen measuring circuit and dissolved oxygen measuring device Download PDFInfo
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- CN113092435A CN113092435A CN202110494123.5A CN202110494123A CN113092435A CN 113092435 A CN113092435 A CN 113092435A CN 202110494123 A CN202110494123 A CN 202110494123A CN 113092435 A CN113092435 A CN 113092435A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
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- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
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- G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
- G05B19/042—Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
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- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
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Abstract
The invention relates to the technical field of dissolved oxygen measurement, and solves the problems of large calculated amount, high requirement on a single chip microcomputer and large power consumption of a circuit for measuring dissolved oxygen by a fluorescence method in the prior art. The utility model provides a fluorescence method dissolved oxygen measuring circuit, includes the collection module, and the collection module is including photosensitive element, IV converting circuit, first order amplifier circuit, second grade amplifier circuit, exclusive-OR gate, RC rectifier circuit, the singlechip that connects gradually, and the RC rectifier circuit is including the first RC rectifier circuit, second RC rectifier circuit and the first impedance matching circuit that connect gradually. The photosensitive element is a silicon photocell or a photodiode. The reflected red light and the red light emitted by the fluorescent substrate are processed by an exclusive-OR gate to form square waves, the square waves are processed by an RC (resistance-capacitance) rectification circuit to form direct-current voltage signals, and the voltage is in direct proportion to the duty ratio of the square waves. The singlechip only needs to process direct current voltage signals and calculate the concentration of the dissolved oxygen according to the voltage, the calculated amount of the singlechip is small, the requirement of a circuit on the singlechip is low, and the energy consumption of the singlechip is reduced.
Description
Technical Field
The invention relates to the technical field of dissolved oxygen measurement, in particular to a fluorescence-method dissolved oxygen measurement circuit and a dissolved oxygen measurement device.
Background
Dissolved Oxygen (Dissolved Oxygen) refers to the amount of Oxygen Dissolved in water, expressed in milligrams of Oxygen per liter of water. The water which is not contaminated is saturated with dissolved oxygen. Clean surface water dissolves oxygen nearly to saturation. If the content of organic matters in water is high, the oxygen consumption speed exceeds the supply speed of oxygen, the dissolved oxygen in water is reduced continuously, when the water body is polluted by the organic matters, the dissolved oxygen in water can even approach zero, and at the moment, the organic matters are decomposed under the anoxic condition to generate the putrefactive fermentation phenomenon, so that the water quality is seriously deteriorated. Therefore, the dissolved oxygen is used as an index of the water pollution degree. Less dissolved oxygen indicates a greater degree of contamination.
The biological treatment in the current sewage treatment mostly adopts the treatment process that the anaerobism combines together with good oxygen, and dissolved oxygen has the effect of playing a vital role in the biological treatment operation of actual waste water, and improper or undulant too big of this index can lead to the activated sludge system to receive the impact rapidly, and then influences treatment effeciency. Therefore, in the actual biochemical treatment process, the content of dissolved oxygen needs to be strictly controlled.
In addition, in aquaculture, fish transport and aquarium applications, dissolved oxygen is monitored to ensure that aquatic organisms have sufficient oxygen in their habitat to survive, grow and reproduce. Some food industries also require measurements of dissolved oxygen, and the oxygen content of wine has a large impact on the quality, stability and longevity of wine. The combination of monitoring and controlling oxygen at different stages of the brewing and bottling process is becoming an increasing concern for breweries. Poor dissolved oxygen can cause discoloration of white wine and deterioration of the flavor of white and red wines.
Typical measurement methods of dissolved oxygen include iodometry, electrode polarography, fluorescence, and the like. The iodometry measurement steps are complicated, not suitable for on-site measurement, and the detection time is relatively long. In the water body where algae grows, the oxygen release amount is increased due to photosynthesis, so that the oxygen in the water may reach an oversaturated state, and at the moment, the measurement of dissolved oxygen in the water by an iodometric method is difficult, and the measurement result is not accurate enough. The method for measuring the dissolved oxygen in water by the electrode polarography is simple and quick in step, relatively low in instrument price and belongs to a national standard method. However, as oxygen is consumed, fouling of the membrane and electrodes occurs, and the formation of an oxygen gradient decreases the reaction rate. If the semi-permeable membrane is damaged, the electrolyte is easily contaminated, which causes the potential of the battery to drift, and the drift is erroneously displayed as the concentration of dissolved oxygen in the water sample, so that the electrolyte and the semi-permeable membrane need to be replaced periodically. The step of measuring the dissolved oxygen in the water by a fluorescence method is simple and quick. Compared with the former two methods, the method for measuring the dissolved oxygen in water by the fluorescence method does not need calibration, has quick response time, stable measurement result, no requirement on flow, no interference, reduced cleaning frequency and low maintenance amount. Atoms of some photosensitive substances return to the ground state in a form of fluorescence emission after being excited, and the presence of oxygen interferes with the behavior, i.e., the more the content of oxygen molecules, the shorter the fluorescence lifetime, and the lower the corresponding intensity, and the content of oxygen in the sample solution can be determined according to the fluorescence intensity or fluorescence lifetime generated by the sample solution. The fluorescence method is characterized in that a blue light source irradiates a substrate to excite the substrate to emit red light, and oxygen molecules can enable the substrate to generate a quenching effect, so that the light intensity and the time for exciting the red light are influenced by the concentration of the oxygen molecules. The method comprises the steps of adopting a red light source synchronous with blue light as reference, adopting a method of fixed point fast sampling and obtaining sine wave by fast Fourier transform to measure the phase difference between excited red light and reference light, comparing the phase difference with an internal calibration value, calculating the concentration of oxygen molecules, and outputting a final value through linearization and temperature compensation. The method has large calculation amount, high requirement on a single chip microcomputer and large power consumption.
Disclosure of Invention
The invention provides a fluorescence method dissolved oxygen measuring circuit and a dissolved oxygen measuring device, and solves the problems that in the prior art, a fluorescence method dissolved oxygen measuring circuit is large in calculation amount, high in requirement on a single chip microcomputer and large in power consumption.
The utility model provides a fluorescence method dissolved oxygen measuring circuit, includes the collection module, and the collection module is including photosensitive element, IV converting circuit, first order amplifier circuit, second grade amplifier circuit, exclusive-OR gate, RC rectifier circuit, the singlechip that connects gradually, and the RC rectifier circuit is including the first RC rectifier circuit, second RC rectifier circuit and the first impedance matching circuit that connect gradually. The photosensitive element is a silicon photocell or a photodiode. When the fluorescent lamp is used, the waveforms of the reflected red light collected by the photosensitive element and the red light emitted by the fluorescent substrate are processed by the exclusive-OR gate to form square waves, the square waves are processed by the RC rectifying circuit to form direct-current voltage signals, and the voltage is in direct proportion to the duty ratio of the square waves. The singlechip only needs to process direct current voltage signals and calculate the concentration of the dissolved oxygen according to the voltage, and the calculated amount of the singlechip is small, so that the requirement of a circuit on the singlechip is low, and the energy consumption of the singlechip is reduced.
Further, a high-pass filter circuit is arranged between the IV conversion circuit and the first-stage amplification circuit, and a high-pass filter circuit is arranged between the first-stage amplification circuit and the second-stage amplification circuit.
Further, the photosensitive element comprises a silicon photocell, the IV conversion circuit comprises an operational amplifier U1.2, a capacitor C54 and a resistor R59, two ends of the capacitor C54 are respectively connected with the inverting input end and the output end of the operational amplifier U1.2, and two ends of the resistor R59 are respectively connected with the inverting input end and the output end of the operational amplifier U1.2.
The light source module comprises a constant current control circuit, a first light source and a second light source, the first light source and the second light source are respectively connected with the constant current control circuit, and the first light source and the second light source are both connected with digital triodes.
Further, the constant current control circuit comprises a filter circuit, an operational amplifier U6 and a current expansion triode Q10 which are connected in sequence.
Further, the power supply module is further included, and the power supply module includes a voltage chip U30, a voltage chip U24, a voltage reference chip Q11, a voltage division circuit and a second impedance matching circuit which are connected in sequence.
Furthermore, the input end of the voltage chip U30 is sequentially connected with a filter circuit, a transient suppression diode TVS2 and an anti-reverse diode D13, the filter circuit is arranged between the voltage chip U30 and the voltage chip U24, and the output end of the voltage chip U24 is connected with the filter circuit.
Further, the second impedance matching circuit comprises an operational amplifier U1.1, an inverting input end of the operational amplifier U1.1 is connected with an output end thereof, and a non-inverting input end of the operational amplifier U1.1 is connected with the voltage division circuit.
The dissolved oxygen measuring device comprises a first cylinder, a second cylinder and a fluorescence method dissolved oxygen measuring circuit, wherein the first cylinder and the second cylinder are detachably connected in a sealing manner, the fluorescence method dissolved oxygen measuring circuit is positioned in the second cylinder, a fluorescence matrix and quartz glass are arranged in the first cylinder, a shading film is arranged on one surface, away from the quartz glass, of the fluorescence matrix, and an optical filter is arranged between the quartz glass and the fluorescence method dissolved oxygen measuring circuit.
Further, be equipped with the mount pad in the second barrel, be equipped with first light source passageway, second light source passageway and detection channel on the mount pad, first light source is located first light source passageway, the second light source is located second light source passageway, photosensitive element is located detection channel.
According to the technical scheme, the invention has the following advantages:
when the fluorescent lamp is used, the waveforms of the reflected red light collected by the photosensitive element and the red light emitted by the fluorescent substrate are processed by the exclusive-OR gate to form square waves, the square waves are processed by the RC rectifying circuit to form direct-current voltage signals, and the voltage is in direct proportion to the duty ratio of the square waves. The singlechip only needs to process direct current voltage signals and calculate the concentration of the dissolved oxygen according to the voltage, and the calculated amount of the singlechip is small, so that the requirement of a circuit on the singlechip is low, and the energy consumption of the singlechip is reduced.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings used in the description will be briefly introduced, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive efforts.
FIG. 1 is a partial circuit diagram of a power supply module according to the present invention;
FIG. 2 is a partial circuit diagram of a power supply module according to the present invention;
FIG. 3 is a partial circuit diagram of a power supply module according to the present invention;
FIG. 4 is a circuit diagram of a temperature measurement module according to the present invention;
FIG. 5 is a partial circuit diagram of an acquisition module of the present invention;
FIG. 6 is a circuit diagram of an analog switch of the present invention;
FIG. 7 is a circuit diagram of an XOR gate of the acquisition module of the present invention;
FIG. 8 is a circuit diagram of an RC rectifier circuit of the acquisition module of the present invention;
FIG. 9 is a circuit diagram of a light source module according to the present invention;
FIG. 10 is a circuit diagram of a single chip microcomputer of the present invention;
fig. 11 is a circuit diagram of an RS485 output module according to the present invention.
Detailed Description
In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the embodiments described below are only a part of embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given in the present patent without making any creative effort, shall fall within the scope of protection of the present patent.
Example 1
As shown in fig. 1-11, a fluorescence-based dissolved oxygen measurement circuit includes an acquisition module, a light source module, a power supply module, a control module, a temperature measurement module, and an RS485 output module.
The power supply module comprises a wire holder P7, an anti-reverse diode D13, a transient suppression diode TVS2, a capacitor C66, a capacitor C56, a resistor R68, an LDO voltage chip (low dropout regulator) U3, a capacitor C68, an inductor L2, a resistor R69, a resistor R70, a capacitor C69, a capacitor C67, a transient suppression diode TVS3, an LDO voltage chip U2, a capacitor C57, a capacitor C58, a voltage reference chip Q11, a capacitor C63, a resistor R62, a resistor R63, a capacitor C61, an operational amplifier U1.1 and a capacitor C64. The 3 third end and the fourth end of the wire holder P7 are connected with the mains supply. The third end of the wire holder P7 is grounded, the fourth end of the wire holder P7 is connected with the anode of an anti-reverse diode D13, the cathode of the anti-reverse diode D13 is connected with the first end of a transient suppression diode TVS2, the second end of the transient suppression diode TVS2 is grounded, the cathode of the anti-reverse diode D13 is connected with the first end of a capacitor C66, the second end of the capacitor C66 is grounded, the first end of a capacitor C66 is connected with the first end of the capacitor C56, the second end of a capacitor C66 is connected with the second end of the capacitor C56, and the VCC output end is formed at the first end of the capacitor C66. A first terminal of the capacitor C56 is connected to a first terminal of the resistor R68, a second terminal of the resistor R68 is connected to the 4 pin of the LDO voltage chip U3, a 5 pin of the LDO voltage chip U3 is connected to a first terminal of the capacitor C56, a 6 pin of the LDO voltage chip U3 is connected to a first terminal of the inductor L2, a 1 pin of the LDO voltage chip U3 is connected to a first terminal of the capacitor C68, a second terminal of the capacitor C68 is connected to a first terminal of the inductor L2, a 2 pin of the LDO voltage chip U3 is grounded, a3 pin of the LDO voltage chip U3 is connected to a first terminal of the resistor R69, a second terminal of the resistor R69 is connected to a second terminal of the inductor L2, a first terminal of the resistor R70 is connected to a first terminal of the resistor R69, a second terminal of the resistor R70 is grounded, a first terminal of the capacitor C69 is connected to a second terminal of the resistor R69, a second terminal of the capacitor C69 is connected to a second terminal of the resistor R69, the second terminal of the capacitor C67 is connected to the first terminal of the resistor R69, the first terminal of the transient suppression diode TVS3 is connected to the second terminal of the resistor R69, the second terminal of the transient suppression diode TVS3 is connected to the first terminal of the resistor R69, the second terminal of the transient suppression diode TVS3 is grounded, and a 5V voltage output terminal is formed at the first terminal of the transient suppression diode TVS 3. The first terminal of the TVS3 is connected to pin 2 (input terminal) of the LDO voltage chip U2, pin 1 of the LDO voltage chip U2 is grounded, pin 3 of the LDO voltage chip U2 is connected to the first terminal of the capacitor C57, the second terminal of the capacitor C57 is grounded, and the first terminal of the capacitor C57 forms a voltage output terminal A3.3V. The 3 pin of the LDO voltage chip U2 is connected to a first terminal of a capacitor C58, and a second terminal of the capacitor C58 is connected to ground. The resistor R62 and the resistor R63 form a voltage division circuit. The capacitor C66, the capacitor C56, the capacitor C69, the capacitor C67, the capacitor C57, the capacitor C58, and the capacitor C61 each constitute a filter circuit.
The 1 pin of the voltage reference chip Q11 is connected to the 5V voltage output terminal, the VREF output terminal is formed on the 2 pin of the voltage reference chip Q11, the 3 pin of the voltage reference chip Q11 is grounded, the first terminal of the capacitor C63 is connected to the 2 pin of the voltage reference chip Q11, and the second terminal of the capacitor C63 is connected to the 3 pin of the voltage reference chip Q11.
The first end of the resistor R62 is connected with the VREF output end, the second end of the resistor R62 is connected with the first end of the resistor R63, the second end of the resistor R63 is grounded, the first end of the capacitor C61 is connected with the first end of the resistor R63, the second end of the capacitor C61 is connected with the second end of the resistor R63, the first end of the resistor R63 is connected with the non-inverting input end of the operational amplifier U1.1, the inverting input end of the operational amplifier U1.1 is connected with the output end of the operational amplifier U1.1, a REF _ mid output end is formed at the output end of the operational amplifier U1.1, the positive power supply of the operational amplifier U1.1 is connected with the A3.3V voltage output end, the positive power supply of the operational amplifier U1.1 is connected with the first end of the capacitor C64, the second end of the capacitor C64 is grounded.
The acquisition module comprises a silicon photocell PD2, a capacitor C54, a resistor R59, an operational amplifier U1.2, a capacitor C55, a resistor R58, an operational amplifier U1.3, a resistor R56, a capacitor C46, a resistor R57, a capacitor C45, a resistor R55, an operational amplifier U7.1, a resistor R53, a capacitor C44, a resistor R54, an exclusive-or gate U4, a resistor R48, a resistor R47, a capacitor C33, a resistor R45, a capacitor C15 and an operational amplifier U7.2. A second terminal of the silicon photocell PD2 is connected to the REF _ mid output terminal, a first terminal of the silicon photocell PD2 is connected to the first terminal of the resistor R59, a first terminal of the silicon photocell PD2 is connected to the first terminal of the capacitor C54, a first terminal of the silicon photocell PD2 is connected to the inverting input terminal of the operational amplifier U1.2, a second terminal of the silicon photocell PD2 is connected to the non-inverting input terminal of the operational amplifier U1.2, a second terminal of the resistor R59 is connected to the output terminal of the operational amplifier U1.2, a second terminal of the capacitor C54 is connected to the output terminal of the operational amplifier U1.2, the output terminal of the operational amplifier U1.2 is connected to the first terminal of the capacitor C55, a second terminal of the capacitor C55 is connected to the first terminal of the resistor R58, a second terminal of the resistor R58 is connected to the REF _ mid output terminal, a second terminal of the capacitor C55 is connected to the non-inverting input terminal of the operational amplifier U1.3, an input terminal of the resistor R57 is connected to the inverting input terminal 57, the inverting input terminal of the operational amplifier U1.3 is connected to the first terminal of the resistor R56, the inverting input terminal of the operational amplifier U1.3 is connected to the first terminal of the capacitor C46, the output terminal of the operational amplifier U1.3 is connected to the second terminal of the resistor R56, the output terminal of the operational amplifier U1.3 is connected to the second terminal of the capacitor C46, the output terminal of the operational amplifier U1.3 is connected to the first terminal of the capacitor C45, the second terminal of the capacitor C45 is connected to the first terminal of the resistor R55, the second terminal of the resistor R55 is connected to the REF _ mid output terminal, the second terminal of the capacitor C45 is connected to the non-inverting input terminal of the operational amplifier U7.1, the inverting input terminal of the operational amplifier U7.1 is connected to the first terminal of the resistor R54, the second terminal of the resistor R54 is connected to the REF _ mid output terminal, the inverting input terminal of the operational amplifier U7.1 is connected to the first terminal of the resistor R53, the inverting input terminal of the operational amplifier U7.1 is connected to the first terminal of the capacitor C63, the output of the ampler U7.1 is connected to the second terminal of the capacitor C44. The operational amplifier U1.2, the resistor R59 and the capacitor C54 form an IV conversion circuit. The capacitor C55 and the resistor R58 form a high-pass filter circuit. The operational amplifier U1.3, the resistor R56, the capacitor C46 and the resistor R57 form a primary amplifying circuit. The operational amplifier U7.1, the resistor R53, the capacitor C44 and the resistor R54 form a two-stage amplifying circuit. The resistor R47 and the capacitor C33 form a primary RC rectifying circuit. The resistor R45 and the capacitor C15 form a secondary RC rectifying circuit. The op amp U7.2 forms a first impedance matching circuit.
The output end of the operational amplifier U7.1 is connected with the 2B input end of the exclusive-OR gate U4, the output end of the exclusive-OR gate U4 is connected with the first end of the resistor R48, and the second end of the resistor R48 is grounded.
The output end of the exclusive-or gate U4 is connected with the first end of the resistor R47, the second end of the resistor R47 is connected with the first end of the capacitor C33, the second end of the capacitor C33 is grounded, the second end of the resistor R47 is connected with the first end of the resistor R45, the second end of the resistor R45 is connected with the first end of the capacitor C15, the second end of the capacitor C15 is grounded, the second end of the resistor R45 is connected with the non-inverting input end of the operational amplifier U7.2, and the inverting input end of the operational amplifier U7.2 is connected with the output end of the operational amplifier U7.2.
The light source module comprises a resistor R60, a capacitor C48, a resistor R66, a capacitor C65, an operational amplifier U6, a capacitor C60, a current-expanding triode Q10, a resistor R61, a light-emitting diode D15, a digital triode Q9, a light-emitting diode D14, a digital triode Q8 and a capacitor C59. The central wavelength of the light emitting diode D15 was 650nm, and the central wavelength of the light emitting diode D14 was 450 nm. A first terminal of a resistor R60 is connected to a first terminal of a capacitor C48, a second terminal of the capacitor C48 is grounded, a first terminal of a resistor R60 is connected to a first terminal of a resistor R66, a second terminal of the resistor R66 is connected to a pin 1 of an operational amplifier U6, a pin 2 of the operational amplifier U6 is grounded, a pin 3 of the operational amplifier U6 is connected to a first terminal of a capacitor C65, a second terminal of a capacitor C65 is connected to a second terminal of a resistor R66, a pin 5 of the operational amplifier U6 is connected to a voltage output terminal A3.3V, a pin 5 of the operational amplifier U6 is connected to a first terminal of a capacitor C60, a second terminal of a capacitor C60 is grounded, a pin 4 of the operational amplifier U6 is connected to a base of a current-expanding transistor Q10, an emitter of a current-expanding transistor Q10 is connected to a pin 3 of the operational amplifier U6, an emitter of the current-expanding transistor Q10 is connected to a first terminal of a capacitor R10, a second terminal of the current-expanding diode 10, the anode of the light emitting diode D15 is connected with the 4 pin of the digital triode Q9, the 3 pin of the digital triode Q9 is connected with the 5V voltage output end, and the 1 pin of the digital triode Q9 is grounded; the collector of the current-expanding triode Q10 is connected with the cathode of the light-emitting diode D14, the anode of the light-emitting diode D14 is connected with the 4 pin of the digital triode Q8, the 3 pin of the digital triode Q8 is connected with the 5V voltage output end, the 3 pin of the digital triode Q8 is connected with the first end of the capacitor C59, the second end of the capacitor C59 is grounded, and the 1 pin of the digital triode Q8 is grounded. The resistor R60, the capacitor C48, the resistor R66, the capacitor C65, the operational amplifier U6, the capacitor C60, the current expansion triode Q10 and the resistor R61 form a constant current control circuit, wherein the resistor R60, the capacitor C48, the resistor R66 and the capacitor C65 form a filter circuit.
The control module comprises a single chip microcomputer U20, a resistor R51, a resistor R49, a capacitor C36, a resistor R50, a light emitting diode LED2, a capacitor C42, a capacitor C43, a crystal oscillator Y2, a resistor R52, a capacitor C37, a capacitor C39, a capacitor C40, a capacitor C41, an analog switch U5 and a resistor R67. A pin 10 of the singlechip U20 is connected with a pin 2 of the digital triode Q9, a pin 11 of the singlechip U20 is connected with a pin 2 of the digital triode Q8, a pin 14 of the singlechip U20 is connected with a pin 1 of the analog switch U5, a pin 15 of the singlechip U20 is connected with an output terminal of the operational amplifier U7.2, a pin 5 of the singlechip U20 is connected with a first terminal of a resistor R52, a pin 6 of the singlechip U20 is connected with a second terminal of a resistor R52, a first terminal of the resistor R52 is connected with a first terminal of a crystal oscillator Y2, a second terminal of the resistor R52 is connected with a second terminal of the crystal oscillator Y2, a first terminal of the resistor R52 is connected with a first terminal of a capacitor C42, a second terminal of the capacitor C42 is grounded, a second terminal of the resistor R52 is connected with a first terminal of a capacitor C7, a second terminal of the capacitor C43 is grounded, a pin 44 of the singlechip U20 is connected with a first terminal of the resistor R20, a second terminal of the singlechip U20 is connected with a second terminal of, the second end of the resistor R49 is connected with a A3.3V voltage output end, the first end of the resistor R49 is connected with the first end of the capacitor C36, the second end of the capacitor C36 is grounded, the 1 pin of the singlechip U20 is connected with an A3.3V voltage output end, the 24 pin, the 36 pin, the 48 pin and the 9 pin of the singlechip U20 are all connected with a A3.3V voltage output end, the 20 pin of the singlechip U20 is connected with the cathode of the LED2, the anode of the LED2 is connected with the first end of the resistor R50, the second end of the resistor R50 is connected with the A3.3V voltage output end, the 41 pin of the singlechip U20 is connected with the 6 pin of the analog switch U5, and the 23 pin, the 35 pin, the 47 pin and the 8 pin of the singlechip U20 are all grounded.
The first terminal of the capacitor C37, the first terminal of the capacitor C39, the first terminal of the capacitor C40, and the first terminal of the capacitor C41 are all connected to the A3.3V voltage output terminal, and the second terminal of the capacitor C37, the second terminal of the capacitor C39, the second terminal of the capacitor C40, and the second terminal of the capacitor C41 are all connected to ground.
The 4 pin of the analog switch U5 is connected to the second terminal of the resistor R60.
The temperature measuring module comprises a thermistor R65, a capacitor C62, a resistor R64 and an operational amplifier U1.4. The first end of the thermistor R65 is connected with the REF _ mid output end, the second end of the thermistor R65 is connected with the first end of the resistor R64, the second end of the resistor R64 is grounded, the first end of the capacitor C62 is connected with the first end of the resistor R64, the second end of the capacitor C62 is connected with the second end of the resistor R64, the second end of the thermistor R65 is connected with the non-inverting input end of the operational amplifier U1.4, the inverting input end of the operational amplifier U1.4 is connected with the output end of the operational amplifier U1.4, and the output end of the operational amplifier U1.4 is connected with the 16 pin of the singlechip U20.
The RS485 output module comprises an RS485 chip U9, a capacitor C21, a resistor R17, a resistor R19, a transient suppression diode TVS3, a transient suppression diode TVS4, a transient suppression diode TVS5, a self-recovery fuse T1 and a self-recovery fuse T2. The 1 pin of an RS485 chip U9 is connected with the 31 pin of a singlechip U20, the 2 pin and the 3 pin of the RS485 chip U9 are both connected with the 32 pin of a singlechip U20, the 4 pin of an RS485 chip U9 is connected with the 30 pin of a singlechip U20, the 5 pin of an RS485 chip U9 is grounded, the 8 pin of an RS485 chip U9 is connected with a 5V voltage output end, the 8 pin of an RS485 chip U9 is connected with a first end of a capacitor C21, the second end of the capacitor C21 is grounded, the 6 pin of an RS485 chip U9 is connected with a first end of a self-recovery fuse T1, the 7 pin of an RS485 chip U9 is connected with a first end of a self-recovery fuse T2, the first end of a resistor R17 is connected with a first end of a capacitor C21, the second end of a resistor R17 is connected with the 6 pin of an RS485 chip U9, the first end of a resistor R19 is connected with a 7 pin of an RS 485U 2, the second end of a transient resistor R56 is connected with a second end 828653 of a transient suppression fuse T, the second terminal of the transient suppression diode TVS3 is grounded, the first terminal of the transient suppression diode TVS5 is connected to the first terminal of the self-recovery fuse T2, the second terminal of the transient suppression diode TVS5 is grounded, the first terminal of the transient suppression diode TVS4 is connected to the first terminal of the self-recovery fuse T1, the second terminal of the transient suppression diode TVS4 is connected to the first terminal of the self-recovery fuse T2, the second terminal of the self-recovery fuse T1 is connected to the second terminal of the wire holder P7, and the second terminal of the self-recovery fuse T2 is connected to the first terminal of the wire holder P7.
Example 2
This embodiment is different from embodiment 1 in that the photosensitive element is a photodiode.
Example 3
The dissolved oxygen measuring device comprises a first cylinder, a second cylinder and a fluorescence method dissolved oxygen measuring circuit, wherein the first cylinder and the second cylinder are detachably connected in a sealing manner, the fluorescence method dissolved oxygen measuring circuit is positioned in the second cylinder, a fluorescence matrix and quartz glass are arranged in the first cylinder, a shading film is arranged on one surface, away from the quartz glass, of the fluorescence matrix, and an optical filter is arranged between the quartz glass and the fluorescence method dissolved oxygen measuring circuit. The filter allows passage of red light with a central wavelength of 650 nm. The second barrel is internally provided with a mounting seat, the mounting seat is provided with a first light source channel, a second light source channel and a detection channel, the light-emitting diode D15 is positioned in the first light source channel, the light-emitting diode D14 is positioned in the second light source channel, and the silicon photocell is positioned in the detection channel.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims and drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (9)
1. The utility model provides a fluorescence method dissolved oxygen measuring circuit, its characterized in that includes the collection module, and the collection module is including photosensitive element, IV converting circuit, one-level amplifier circuit, second grade amplifier circuit, exclusive-OR gate, RC rectifier circuit, the singlechip that connects gradually, and RC rectifier circuit is including the first RC rectifier circuit, second RC rectifier circuit and the first impedance matching circuit that connect gradually.
2. The fluorescence-based dissolved oxygen measurement circuit according to claim 1, wherein a high-pass filter circuit is provided between the IV conversion circuit and the first-stage amplification circuit, and a high-pass filter circuit is provided between the first-stage amplification circuit and the second-stage amplification circuit.
3. The fluorometric dissolved oxygen measuring circuit of claim 2, wherein the light sensing element comprises a silicon photocell, the IV conversion circuit comprises an operational amplifier U1.2, a capacitor C54 and a resistor R59, wherein two ends of the capacitor C54 are connected to the inverting input terminal and the output terminal of the operational amplifier U1.2, respectively, and two ends of the resistor R59 are connected to the inverting input terminal and the output terminal of the operational amplifier U1.2, respectively.
4. The fluorescence-method dissolved oxygen measurement circuit according to claim 1, 2 or 3, further comprising a light source module, wherein the light source module comprises a constant current control circuit, a first light source and a second light source, the first light source and the second light source are respectively connected with the constant current control circuit, and the first light source and the second light source are both connected with digital triodes.
5. The fluorescence-based dissolved oxygen measurement circuit of claim 4, wherein the constant current control circuit comprises a filter circuit, an amplifier U6 and a current expansion triode Q10 which are connected in sequence.
6. The fluorescence method dissolved oxygen measurement circuit according to claim 4, further comprising a power supply module, wherein the power supply module comprises a voltage chip U30, a voltage chip U24, a voltage reference chip Q11, a voltage division circuit and a second impedance matching circuit which are connected in sequence.
7. The fluorescence method dissolved oxygen measurement circuit according to claim 6, wherein the input end of the voltage chip U30 is sequentially connected with a filter circuit, a transient suppression diode TVS2 and an anti-reverse diode D13, the filter circuit is arranged between the voltage chip U30 and the voltage chip U24, and the output end of the voltage chip U24 is connected with the filter circuit.
8. The fluorescence method dissolved oxygen measurement circuit according to claim 7, wherein the second impedance matching circuit comprises an operational amplifier U1.1, an inverting input terminal of the operational amplifier U1.1 is connected to an output terminal thereof, and a non-inverting input terminal of the operational amplifier U1.1 is connected to the voltage dividing circuit.
9. The dissolved oxygen measuring device is characterized by comprising a first cylinder, a second cylinder and the fluorescence dissolved oxygen measuring circuit according to any one of claims 1 to 8, wherein the first cylinder and the second cylinder are detachably and hermetically connected, the fluorescence dissolved oxygen measuring circuit is positioned in the second cylinder, a fluorescence matrix and quartz glass are arranged in the first cylinder, a light shielding film is arranged on one surface, away from the quartz glass, of the fluorescence matrix, and a light filter is arranged between the quartz glass and the fluorescence dissolved oxygen measuring circuit.
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| CN202110494123.5A CN113092435A (en) | 2021-05-07 | 2021-05-07 | Fluorescence method dissolved oxygen measuring circuit and dissolved oxygen measuring device |
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| CN202110494123.5A CN113092435A (en) | 2021-05-07 | 2021-05-07 | Fluorescence method dissolved oxygen measuring circuit and dissolved oxygen measuring device |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113418967A (en) * | 2021-07-16 | 2021-09-21 | 山东仁科测控技术有限公司 | Liquid conductivity measuring circuit |
| CN113655011A (en) * | 2021-10-20 | 2021-11-16 | 武汉新烽光电股份有限公司 | Microfluidic detection system and detection method thereof |
| CN117147517A (en) * | 2023-10-31 | 2023-12-01 | 青岛海研电子有限公司 | Circuit for detecting dissolved oxygen |
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2021
- 2021-05-07 CN CN202110494123.5A patent/CN113092435A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113418967A (en) * | 2021-07-16 | 2021-09-21 | 山东仁科测控技术有限公司 | Liquid conductivity measuring circuit |
| CN113655011A (en) * | 2021-10-20 | 2021-11-16 | 武汉新烽光电股份有限公司 | Microfluidic detection system and detection method thereof |
| CN113655011B (en) * | 2021-10-20 | 2022-02-08 | 武汉新烽光电股份有限公司 | Microfluidic detection system and detection method thereof |
| CN117147517A (en) * | 2023-10-31 | 2023-12-01 | 青岛海研电子有限公司 | Circuit for detecting dissolved oxygen |
| CN117147517B (en) * | 2023-10-31 | 2024-03-22 | 青岛海研电子有限公司 | Circuit for detecting dissolved oxygen |
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