CN202196014U - Turbidity measuring circuit based on photosensitive diode - Google Patents
Turbidity measuring circuit based on photosensitive diode Download PDFInfo
- Publication number
- CN202196014U CN202196014U CN2011203364745U CN201120336474U CN202196014U CN 202196014 U CN202196014 U CN 202196014U CN 2011203364745 U CN2011203364745 U CN 2011203364745U CN 201120336474 U CN201120336474 U CN 201120336474U CN 202196014 U CN202196014 U CN 202196014U
- Authority
- CN
- China
- Prior art keywords
- operational amplifier
- resistance
- capacitor
- terminations
- ground connection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Landscapes
- Amplifiers (AREA)
Abstract
The utility model discloses a turbidity measuring circuit based on a photosensitive diode. A 555 timer generates a square-wave signal to control the work state of a light-emitting diode; liquid turbidity is converted into a photoelectric signal by the light-emitting diode and the photosensitive diode and then is measured; a low current signal is converted into a voltage signal through operational amplifiers and the voltage signal is amplified, at the same time, owing to phase compensation and wave filtering during the conversion, the voltage signal capable of A/D conversion is generated. The utility model controls the on/off of triodes by utilizing a square-wave generating circuit with a duty cycle of 1:2 and generated by the 555 timer, so as to realize the regulation of a light source, and further prevent the interference brought by natural light.
Description
Technical field
The utility model belongs to the Detection of Weak Signals field, especially a kind of turbidimetry circuit based on photodiode.
Background technology
Now the turbidity transducer overwhelming majority of usefulness is a photonephelometer, and the light-receiving that light source is sent with the device of photoelectric cell and so on also converts electric signal into and handles.The turbidity notion all will obtain using in many industries.Just need strict control water quality in the waterworks, to guarantee the healthy of people, suspension can increase the incidence probability of infectious disease too much in the potable water.The hydrometric station also need be monitored water quality.And the atmospheric researcher needs the pollution level of many air to study, the toxic emission of various factories, and the use of hydraulic valve all will be studied the pollution level of using medium.Also have Beer Production, medicament production, manufacturing film, production glass, manufacturing paper all will in production procedure, monitor to the medium turbidity.Turbidity also is the notion of often using in medical research, for example all will use the notion of turbidity to the mensuration of various cells, number of bacteria and various content of material in the blood.The turbidity monitoring is carried out in the inland river, can be understood the silt loss situation, the content of microorganism in water pollution condition and the water.The turbidity monitoring is carried out in offshore waters, can understand the content of suspended biological.Deep-marine-environment is carried out the turbidity monitoring, can survey suspended biological content and seabed abnormal conditions, seek mineral deposit or interested environment.
Summary of the invention
The utility model has proposed a kind of turbidimetry circuit based on photodiode to the deficiency of prior art.The technical scheme that the utility model technical solution problem is adopted is:
Turbidimetry circuit based on photodiode comprises radiating circuit and receiving circuit two parts.
Radiating circuit partly comprises the 8th resistance R 8, the 9th resistance R 9, the tenth resistance R the 10, the 11 resistance R the 11, the 12 resistance R the 12, the 13 resistance R the 13, the 11 filter capacitor C11, the 12 filter capacitor C12, the 13 filter capacitor C13, the 14 filter capacitor C14, emitting diode D1, the first triode Q1, the second triode Q2, the 3rd operational amplifier U3, NE555P timer U4.
7 pin of the 8th resistance R 8 one termination NE555P timer U4,2 pin and 6 pin of another termination NE555P timer U4,4 pin of the 9th resistance R 9 one termination NE555P timer U4; 7 pin of another ground termination NE555P timer U4,3 pin of the tenth resistance R 10 1 termination NE555P timer U4, the base stage of another termination first triode Q1; 2 and 6 pin of the 11 capacitor C 11 1 termination NE555P timer U4, other end ground connection, 5 pin of the 12 capacitor C 12 1 termination NE555P timer U4; Other end ground connection, the 1 pin ground connection of NE555P timer U4,2 pin are connected with 6 pin; 4 pin and 8 pin connect the power supply of voltage for+3.3V, the collector of the 11 resistance R 11 1 terminations first triode Q1, the in-phase input end of another termination the 3rd operational amplifier U3; The in-phase input end of the 12 resistance R 12 1 terminations the 3rd operational amplifier U3, other end ground connection, the homophase power input of the 13 capacitor C 13 1 terminations the 3rd operational amplifier U3; Other end ground connection, the inverting power supplies input end of the 14 capacitor C 14 1 terminations the 3rd operational amplifier U3, other end ground connection; The base stage of the first triode Q1 connects the tenth resistance R 10, and collector connects the 11 resistance R 11, and emitter connects the power supply of voltage for+3.3V; The base stage of the second triode Q2 connects the output terminal of the 3rd operational amplifier U3, and diode D1 is penetrated in the collector sending and receiving, and emitter connects the inverting input of the 3rd operational amplifier U3; The inverting input of the 13 resistance R 13 1 terminations the 3rd operational amplifier U3; Other end ground connection, emitting diode D1 one termination voltage is+power supply of 5V, and the collector of another termination second triode Q2; The homophase power input of the 3rd operational amplifier U3 connects the power supply of voltage for+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V.
Receiving circuit partly comprises first resistance R 1; Second resistance R 2; The 3rd resistance R 3; The 4th resistance R 4; The 5th resistance R 5; The 6th resistance R 6; The 7th resistance R 7; The first phase compensation capacitor C 1; The second filter capacitor C2; The 3rd filter capacitor C3; The 4th filter capacitor C4; The 5th filter capacitor C5; The 6th filter capacitor C6; The 7th filter capacitor C7; The 8th filter capacitor C8; The 9th filter capacitor C9; The tenth filter capacitor C10; Reception diode D2; The first operational amplifier U1; The second operational amplifier U2.
First resistance R, 1 one end ground connection, the in-phase input end of another termination first operational amplifier U1, first capacitor C, 1 one end ground connection; The in-phase input end of another termination first operational amplifier U1, the inverting input of second resistance R, 2 one terminations, the first operational amplifier U1, the output terminal of another termination first operational amplifier U1; The inverting input of second capacitor C, 2 one terminations, the first operational amplifier U1, the output terminal of another termination first operational amplifier U1, the output terminal of the 3rd resistance R 3 one terminations first operational amplifier U1; The inverting input of another termination second operational amplifier U2, the output terminal of the 3rd capacitor C 3 one terminations first operational amplifier U1, other end ground connection; The inverting input of the 4th capacitor C 4 one terminations second operational amplifier U2, other end ground connection, the homophase power input of the 6th capacitor C 6 one terminations first operational amplifier U1; Other end ground connection, the inverting power supplies input end of the 7th capacitor C 7 one terminations first operational amplifier U1, other end ground connection; The 5th resistance R 5 one end ground connection, the in-phase input end of another termination second operational amplifier U2, the inverting input of the 5th capacitor C 5 one terminations second operational amplifier U2; The output terminal of another termination second operational amplifier U2, the 4th resistance R 4 one end ground connection, the inverting input of another termination second operational amplifier U2; The inverting input of the 6th resistance R 6 one terminations second operational amplifier U2, the output terminal of another termination second operational amplifier U2, the output terminal of the 7th resistance R 7 one terminations second operational amplifier U2; The 3rd of another termination A/D conversion chip, the homophase power input of the 8th capacitor C 8 one terminations second operational amplifier U2, other end ground connection; The inverting power supplies input end of the 9th capacitor C 9 one terminations second operational amplifier U2; Other end ground connection, the tenth capacitor C 10 1 end ground connection, the 3rd of another termination A/D conversion chip; The termination voltage of reception diode D2 is+power supply of 5V; The inverting input of another termination first operational amplifier U1, the homophase power input of the first operational amplifier U1 connect the power supply of voltage for+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V; The homophase power input of the second operational amplifier U2 connects the power supply of voltage for+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V.
The utility model can be avoided the influence of natural light and receiving device dark current, through each parameter in the circuit is set, carries out repeatedly filtering and phase compensation, makes this circuit that noise robustness preferably arranged.
Description of drawings
Fig. 1 is the radiating circuit of the circuit diagram of the utility model;
Fig. 2 is the receiving circuit of the circuit diagram of the utility model.
Embodiment
Below in conjunction with accompanying drawing the utility model is further described.
Turbidimetry circuit based on photodiode comprises radiating circuit and receiving circuit two parts.
As shown in Figure 1, radiating circuit partly comprises the 8th resistance R 8, the 9th resistance R 9, the tenth resistance R the 10, the 11 resistance R the 11, the 12 resistance R the 12, the 13 resistance R the 13, the 11 filter capacitor C11, the 12 filter capacitor C12, the 13 filter capacitor C13, the 14 filter capacitor C14, emitting diode D1, the first triode Q1, the second triode Q2, the 3rd operational amplifier U3, NE555P timer U4.
7 pin of the 8th resistance R 8 one termination NE555P timer U4,2 pin and 6 pin of another termination NE555P timer U4,4 pin of the 9th resistance R 9 one termination NE555P timer U4; 7 pin of another ground termination NE555P timer U4,3 pin of the tenth resistance R 10 1 termination NE555P timer U4, the base stage of another termination first triode Q1; 2 and 6 pin of the 11 capacitor C 11 1 termination NE555P timer U4, other end ground connection, 5 pin of the 12 capacitor C 12 1 termination NE555P timer U4; Other end ground connection, the 1 pin ground connection of NE555P timer U4,2 pin are connected with 6 pin; 4 pin and 8 pin connect the power supply of voltage for+3.3V, the collector of the 11 resistance R 11 1 terminations first triode Q1, the in-phase input end of another termination the 3rd operational amplifier U3; The in-phase input end of the 12 resistance R 12 1 terminations the 3rd operational amplifier U3, other end ground connection, the homophase power input of the 13 capacitor C 13 1 terminations the 3rd operational amplifier U3; Other end ground connection, the inverting power supplies input end of the 14 capacitor C 14 1 terminations the 3rd operational amplifier U3, other end ground connection; The base stage of the first triode Q1 connects the tenth resistance R 10, and collector connects the 11 resistance R 11, and emitter connects the power supply of voltage for+3.3V; The base stage of the second triode Q2 connects the output terminal of the 3rd operational amplifier U3, and diode D1 is penetrated in the collector sending and receiving, and emitter connects the inverting input of the 3rd operational amplifier U3; The inverting input of the 13 resistance R 13 1 terminations the 3rd operational amplifier U3; Other end ground connection, emitting diode D1 one termination voltage is+power supply of 5V, and the collector of another termination second triode Q2; The homophase power input of the 3rd operational amplifier U3 connects the power supply of voltage for+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V.
As shown in Figure 2, receiving circuit partly comprises first resistance R 1, second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the first phase compensation capacitor C 1, the second filter capacitor C2, the 3rd filter capacitor C3, the 4th filter capacitor C4, the 5th filter capacitor C5, the 6th filter capacitor C6, the 7th filter capacitor C7, the 8th filter capacitor C8, the 9th filter capacitor C9, the tenth filter capacitor C10, reception diode D2, the first operational amplifier U1, the second operational amplifier U2.
First resistance R, 1 one end ground connection, the in-phase input end of another termination first operational amplifier U1, first capacitor C, 1 one end ground connection; The in-phase input end of another termination first operational amplifier U1, the inverting input of second resistance R, 2 one terminations, the first operational amplifier U1, the output terminal of another termination first operational amplifier U1; The inverting input of second capacitor C, 2 one terminations, the first operational amplifier U1, the output terminal of another termination first operational amplifier U1, the output terminal of the 3rd resistance R 3 one terminations first operational amplifier U1; The inverting input of another termination second operational amplifier U2, the output terminal of the 3rd capacitor C 3 one terminations first operational amplifier U1, other end ground connection; The inverting input of the 4th capacitor C 4 one terminations second operational amplifier U2, other end ground connection, the homophase power input of the 6th capacitor C 6 one terminations first operational amplifier U1; Other end ground connection, the inverting power supplies input end of the 7th capacitor C 7 one terminations first operational amplifier U1, other end ground connection; The 5th resistance R 5 one end ground connection, the in-phase input end of another termination second operational amplifier U2, the inverting input of the 5th capacitor C 5 one terminations second operational amplifier U2; The output terminal of another termination second operational amplifier U2, the 4th resistance R 4 one end ground connection, the inverting input of another termination second operational amplifier U2; The inverting input of the 6th resistance R 6 one terminations second operational amplifier U2, the output terminal of another termination second operational amplifier U2, the output terminal of the 7th resistance R 7 one terminations second operational amplifier U2; The 3rd of another termination A/D conversion chip, the homophase power input of the 8th capacitor C 8 one terminations second operational amplifier U2, other end ground connection; The inverting power supplies input end of the 9th capacitor C 9 one terminations second operational amplifier U2; Other end ground connection, the tenth capacitor C 10 1 end ground connection, the 3rd of another termination A/D conversion chip; The termination voltage of reception diode D2 is+power supply of 5V; The inverting input of another termination first operational amplifier U1, the homophase power input of the first operational amplifier U1 connect the power supply of voltage for+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V; The homophase power input of the second operational amplifier U2 connects the power supply of voltage for+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V.
The groundwork principle and the process of this circuit:
The infrared light that emitting diode D1 sends produces scattering in liquid environment; The power that how much has determined the scattered light that reception diode D2 receives of suspension number in the liquid environment; Thereby further determined the power of the photocurrent that reception diode D2 produces; And how much the suspension content in the liquid be the important indicator of weighing the liquid turbidity size, therefore can measure the turbidity of liquid through scattered light method.This circuit is measured the turbidity that ratio juris is measured liquid through scattered light just.
At first, the dutycycle that produces through the NE555P timer is the square wave generation circuit of 1:2.The resistance of the 8th resistance R 8 is 100K Ω, and the resistance of the 9th resistance R 9 is 1K Ω, and the capability value of the 11 capacitor C 11 and the 12 capacitor C 12 all is 10nF.Some more oscillators according to being made up of the NE555P timer have:
Oscillation period
The dutycycle of output waveform
Control emitting diode D1 work through the on-off action of the first triode Q1 again.The resistance of the tenth resistance R 10 is 1K Ω, and the resistance of the 11 resistance R 11 and the 12 resistance R 12 all is 1K Ω, and the resistance of the 13 resistance R 13 is 60 Ω; One termination of emitting diode D1+5V power supply first triode Q1 plays the effect of switch, when the low level of the square wave of NE555P timer U4 output, and the first triode Q1 conducting; The supply voltage of+3.3V is through the dividing potential drop effect of the 11 resistance R 11 and the 12 resistance R 12, produces the voltage of pact+1.6V at the positive input of the 3rd operational amplifier U3, and the output terminal of the 3rd operational amplifier U3 is at this moment also exported a forward voltage; Control the second triode Q2 conducting; Emitting diode D1 begins luminous, and when the high level of the square wave of NE555P timer U4 output, the first triode Q1 ends; Owing to there is the influence of each device dark electric current; After through the amplification of the 3rd operational amplifier U3, export a low level at its output terminal, control the second triode Q2 and end, emitting diode D1 begins to extinguish.
In receiving circuit, reception diode D2 reversal connection+5V power supply produces low current signal when receiving the signal of emitting diode D1 emission, and signal is through the negative input input of the first operational amplifier U1; Convert low current signal into voltage signal output, the resistance of second resistance R 2 is 100K Ω, plays degenerative effect, and first resistance R 1 is a biasing resistor; Resistance is 100K Ω, and first capacitor C 1 is phase compensation electric capacity, and capability value is 0.1uF, and second capacitor C 2 is a filter capacitor; Capability value is 15pF, the voltage signal process current-limiting resistance R3 of first operational amplifier U1 output, and after the filtering of the 3rd capacitor C 3 and the 4th capacitor C 4, be input to the negative input of the second operational amplifier U2; The resistance of the 3rd resistance R 3 is 1K Ω, and the capability value of the 3rd electric capacity and the 4th electric capacity all is 100pF, and the 5th resistance R 5 is a biasing resistor; Resistance is 1K Ω, and the resistance of the 4th resistance R 4 is 1K Ω, and the 6th resistance R 6 is an adjustable resistance; Resistance is 10K Ω, and voltage signal just can carry out the AD conversion after through the further amplification of the second operational amplifier U2, and the 5th capacitor C 5 is a filter capacitor; Capability value is 100pF, and the 7th resistance R 7 is a current-limiting resistance, and resistance is 100 Ω; The 8th capacitor C 8 and the 9th capacitor C 9 are power filtering capacitors, and capability value is 0.1uF, and the tenth capacitor C 10 is filter capacitors; Capability value is 0.1uF, and current signal amplifies through the two-stage of receiving circuit, has finally realized the voltage transitions of low current signal.
Claims (1)
1. based on the turbidimetry circuit of photodiode, comprise radiating circuit and receiving circuit two parts, it is characterized in that:
Radiating circuit partly comprises the 8th resistance R 8, the 9th resistance R 9, the tenth resistance R the 10, the 11 resistance R the 11, the 12 resistance R the 12, the 13 resistance R the 13, the 11 filter capacitor C11, the 12 filter capacitor C12, the 13 filter capacitor C13, the 14 filter capacitor C14, emitting diode D1, the first triode Q1, the second triode Q2, the 3rd operational amplifier U3 and NE555P timer U4,7 pin of the 8th resistance R 8 one termination NE555P timer U4,2 pin and 6 pin of another termination NE555P timer U4; 4 pin of the 9th resistance R 9 one termination NE555P timer U4,7 pin of another ground termination NE555P timer U4,3 pin of the tenth resistance R 10 1 termination NE555P timer U4; The base stage of another termination first triode Q1,2 and 6 pin of the 11 capacitor C 11 1 termination NE555P timer U4, other end ground connection; 5 pin of the 12 capacitor C 12 1 termination NE555P timer U4, other end ground connection, the 1 pin ground connection of NE555P timer U4; 2 pin are connected with 6 pin, and 4 pin and 8 pin connect the power supply of voltage for+3.3V, the collector of the 11 resistance R 11 1 terminations first triode Q1; The in-phase input end of another termination the 3rd operational amplifier U3, the in-phase input end of the 12 resistance R 12 1 terminations the 3rd operational amplifier U3, other end ground connection; The homophase power input of the 13 capacitor C 13 1 terminations the 3rd operational amplifier U3; Other end ground connection, the inverting power supplies input end of the 14 capacitor C 14 1 terminations the 3rd operational amplifier U3, other end ground connection; The base stage of the first triode Q1 connects the tenth resistance R 10; Collector connects the 11 resistance R 11, and emitter connects the power supply of voltage for+3.3V, and the base stage of the second triode Q2 connects the output terminal of the 3rd operational amplifier U3; Diode D1 is penetrated in the collector sending and receiving; Emitter connects the inverting input of the 3rd operational amplifier U3, the inverting input of the 13 resistance R 13 1 terminations the 3rd operational amplifier U3, other end ground connection; Emitting diode D1 one termination voltage is+power supply of 5V; The collector of another termination second triode Q2, the homophase power input of the 3rd operational amplifier U3 connect the power supply of voltage for+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V;
Receiving circuit partly comprises first resistance R 1, second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the first phase compensation capacitor C 1, the second filter capacitor C2, the 3rd filter capacitor C3, the 4th filter capacitor C4, the 5th filter capacitor C5, the 6th filter capacitor C6, the 7th filter capacitor C7, the 8th filter capacitor C8, the 9th filter capacitor C9, the tenth filter capacitor C10, reception diode D2, the first operational amplifier U1 and the second operational amplifier U2, first resistance R, 1 one end ground connection, the in-phase input end of another termination first operational amplifier U1; First capacitor C, 1 one end ground connection, the in-phase input end of another termination first operational amplifier U1, the inverting input of second resistance R, 2 one terminations, the first operational amplifier U1; The output terminal of another termination first operational amplifier U1, the inverting input of second capacitor C, 2 one terminations, the first operational amplifier U1, the output terminal of another termination first operational amplifier U1; The output terminal of the 3rd resistance R 3 one terminations first operational amplifier U1, the inverting input of another termination second operational amplifier U2, the output terminal of the 3rd capacitor C 3 one terminations first operational amplifier U1; Other end ground connection, the inverting input of the 4th capacitor C 4 one terminations second operational amplifier U2, other end ground connection; The homophase power input of the 6th capacitor C 6 one terminations first operational amplifier U1; Other end ground connection, the inverting power supplies input end of the 7th capacitor C 7 one terminations first operational amplifier U1, other end ground connection; The 5th resistance R 5 one end ground connection; The in-phase input end of another termination second operational amplifier U2, the inverting input of the 5th capacitor C 5 one terminations second operational amplifier U2, the output terminal of another termination second operational amplifier U2; The 4th resistance R 4 one end ground connection; The inverting input of another termination second operational amplifier U2, the inverting input of the 6th resistance R 6 one terminations second operational amplifier U2, the output terminal of another termination second operational amplifier U2; The output terminal of the 7th resistance R 7 one terminations second operational amplifier U2; The 3rd of another termination A/D conversion chip, the homophase power input of the 8th capacitor C 8 one terminations second operational amplifier U2, other end ground connection; The inverting power supplies input end of the 9th capacitor C 9 one terminations second operational amplifier U2; Other end ground connection, the tenth capacitor C 10 1 end ground connection, the 3rd of another termination A/D conversion chip; The termination voltage of reception diode D2 is+power supply of 5V; The inverting input of another termination first operational amplifier U1, the homophase power input of the first operational amplifier U1 connect the power supply of voltage for+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V; The homophase power input of the second operational amplifier U2 connects the power supply of voltage for+3.3V, and inverting power supplies input termination voltage is-power supply of 3.3V.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2011203364745U CN202196014U (en) | 2011-09-08 | 2011-09-08 | Turbidity measuring circuit based on photosensitive diode |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2011203364745U CN202196014U (en) | 2011-09-08 | 2011-09-08 | Turbidity measuring circuit based on photosensitive diode |
Publications (1)
Publication Number | Publication Date |
---|---|
CN202196014U true CN202196014U (en) | 2012-04-18 |
Family
ID=45950917
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN2011203364745U Expired - Lifetime CN202196014U (en) | 2011-09-08 | 2011-09-08 | Turbidity measuring circuit based on photosensitive diode |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN202196014U (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102393384A (en) * | 2011-09-08 | 2012-03-28 | 杭州电子科技大学 | Photosensitive diode-based turbidity 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 |
-
2011
- 2011-09-08 CN CN2011203364745U patent/CN202196014U/en not_active Expired - Lifetime
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102393384A (en) * | 2011-09-08 | 2012-03-28 | 杭州电子科技大学 | Photosensitive diode-based turbidity measuring circuit |
CN102393384B (en) * | 2011-09-08 | 2013-03-13 | 杭州电子科技大学 | Photosensitive diode-based turbidity 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 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN102393384B (en) | Photosensitive diode-based turbidity measuring circuit | |
CN205483072U (en) | Soil erosion and water loss sediment charge automatic monitoring appearance | |
CN202196014U (en) | Turbidity measuring circuit based on photosensitive diode | |
CN104849238A (en) | Infrared turbidity detection device | |
CN208012769U (en) | A kind of excessively high warning circuit of temperature based on integrated transporting discharging | |
CN102349388A (en) | Fertilizer applicator monitoring system | |
CN204301918U (en) | Metered pressure sensor signal amplifying circuit | |
CN104345130A (en) | Monitoring system for underground water around chemical plant | |
CN203837772U (en) | Rice field irrigation and drainage coupling water level remote detector | |
CN203097948U (en) | Multi-parameter sensor for coal mine | |
CN201964951U (en) | Vibration-preventing device for tree seedling | |
CN204720956U (en) | A kind of three-phase uninterrupted power supply with lack detection circuit | |
CN204556100U (en) | A kind of novel acoustical signal acquisition system | |
CN204926390U (en) | A alarm system for gardens monitoring based on thing networking | |
CN204832159U (en) | Water quality monitoring system based on thing networking | |
CN205449785U (en) | High accuracy quality of water sensing monitoring system based on thing networking | |
CN203422137U (en) | Oil level measurement switching circuit | |
CN202771291U (en) | Practical plant growth environment monitor and control system | |
CN206496788U (en) | A kind of novel intelligent environmental monitoring terminal | |
CN201278194Y (en) | Domestic earthquake water wave alarm | |
CN212364073U (en) | Seawater turbidity measuring device | |
TW201435817A (en) | Shipment detecting system | |
CN218734205U (en) | Photosensitive signal amplification circuit of photovoltaic mode | |
CN204330015U (en) | A kind of farmland supervisory system | |
CN204269659U (en) | A kind of water quality online auto monitoring system |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C14 | Grant of patent or utility model | ||
GR01 | Patent grant | ||
AV01 | Patent right actively abandoned |
Granted publication date: 20120418 Effective date of abandoning: 20130313 |
|
AV01 | Patent right actively abandoned |
Granted publication date: 20120418 Effective date of abandoning: 20130313 |
|
RGAV | Abandon patent right to avoid regrant |