CN2387537Y - Capacity type wet sensitive multifunctional sensor - Google Patents
Capacity type wet sensitive multifunctional sensor Download PDFInfo
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- CN2387537Y CN2387537Y CN 99213978 CN99213978U CN2387537Y CN 2387537 Y CN2387537 Y CN 2387537Y CN 99213978 CN99213978 CN 99213978 CN 99213978 U CN99213978 U CN 99213978U CN 2387537 Y CN2387537 Y CN 2387537Y
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Abstract
The utility model relates to a capacitor type wet sensitive multifunctional sensor, which is composed of a capacitor type wet sensitive probe which is composed of an insulated inner and an insulated outer barrel sleeves which are concentrically arranged and are made of corrosion resistant metal material, and a sensor circuit which composed of a single chip computer circuit matched to work with the probe, and a called 'imaginary part method capacity checking circuit', etc. The sensor can rapidly and accurately detect the physical quantities of the water content of the air, the temperature, the relative humidity, the dew point, etc. The utility model has the advantages of simple and compact structure, strong anti-interference capability, strong anti-pollution capability, and strong anti-corrosion capability. The utility model overcomes the weakness that the existing film capacitor wet sensitive multifunctional sensor can not be used in the pollution and the corrosion environments.
Description
The utility model is a kind of condenser type moisture sensor.Be particularly related to a kind of anticorrosive, contamination resistance is strong, can measure the wet quick Multifunction Sensor of condenser type of physical quantitys such as air moisture content, humidity fast.
Existing air humidity is measured: the one, adopt wet-and-dry bulb thermometer.Dry bulb thermometer is measured the temperature of air, and wet bulb thermometer is measured the temperature of the other end wet cotton yarn under water, with do, the temperature value of wet bulb is by calculating or tabling look-up, and tries to achieve the relative humidity of air.Its shortcoming is slow in reacting, measures slowly, is subjected to wind effect, easily pollution failure and manipulate inconvenience; Other or use thin-film capacitor formula moisture sensor, its detector probe is the High-Polymer Capacitance formula humidity-sensitive element of responsive relative humidity.Above-mentioned relatively wet-and-dry bulb thermometer advantage is a lot, but still has sensitive element be afraid of to pollute, and is afraid of corrosion, so that can not use dust being arranged or contain in the environment of corrosive gas, or the weakness of very easily damaging in this environment.
Task of the present utility model is the deficiency that overcomes existing thin-film capacitor formula moisture sensor, design a kind of can the electric conductivity dust pollution is arranged and the air of the gas that is corrosive in use and the condenser type moisture sensor that can measure fast.This sensor has multiple functions such as the air moisture content of measurement, relative humidity, temperature.
The technical solution of the utility model is: contain the wet quick probe of condenser type and with the sensor circuit of probe associated working.Described probe is characterized in that containing inner core 5 and the overcoat 9 that is linked in 2,14 of upper and lower end caps with core insulation.In, outer jacket casing 5,9 by erosion-resisting metal material making, constitute the measurement utmost point and the ground electrode of wet quick probe electric capacity respectively, also be provided with to insulation equipotential driving stage 8 on the inside surface of inner core 5, sensor circuit board 7 quilts hermetically, and to realize that with above-mentioned electrode the mode of corresponding connection is installed in the inner core 5, the central portion of upper end cover 2 is provided with circuit board 7 and realizes cable or the socket 1 that respective electrical connects, one temperature sensing element 12 expressions that respective electrical connects are arranged is installed in the probe suitable position with circuit board, on the annular cavity that constitutes by the inner core overcoat, there is the duct that is in communication with the outside at following two ends, and can circulate in above-mentioned ring cavity so that detect medium air.(referring to accompanying drawing 1) described sensor circuit is characterized in that containing a kind of " imaginary part method capacitive detection circuit ".So-called " imaginary part method capacitive detection circuit " (inventor has application for a patent for invention in addition) is meant and contains carrier signal generation circuit 73, carrier system metering circuit 74 and imaginary signals separation circuit 75, measured capacitance CX one utmost point ground connection, another utmost point access carrier formula metering circuit 74, the carrier signal generation circuit 73 generation constant amplitudes triangular wave carrier signal UI of frequency surely are transported to carrier system metering circuit 74, metering circuit 74 outputs are by the solid part signal of the leakage resistance decision of carrier wave and measured capacitance, reach the synthetic complex signal of imaginary signals by the measured capacitance decision, be transported to imaginary signals separation circuit 75 respectively with the same frequency square-wave signal UK of another and UI phase differential 90 degree, 75 of imaginary signals separation circuits can be exported a kind of like this capacitive detection circuit of the electric signal UO that is proportional to measured capacitance; In addition, sensor circuit also contains the power circuit 71 that positive and negative stabilized voltage supply VCC, VSS can be provided to each circuit, single chip circuit 72, and subtracter 76, amplifier 77, temperature measuring circuit 78 are amplified in filtering; Frequency f of PWM controller output of single chip circuit 72 is stable, amplitude stabilization equals VCC and receives carrier signal generation circuit 73 to the symmetrical square wave on ground, the electric signal UO of imaginary signals separation circuit 75 outputs connects filtering and amplifies subtracter 76, filtering is amplified subtracter 76 outputs through the signal of the calibrate signal that is proportional to air moisture content after amplifier 77 amplifies again, receive the corresponding interface AD0 of single chip circuit 72 respectively with the temperature voltage signal of temperature measuring circuit 78 output, AD1, single-chip microcomputer is with the air themperature value that records, water percentage value and the relative air humidity that calculates in view of the above, values such as dew point are with serial line interface SIO output digital signal, or be proportional to the DC voltage of relative air humidity with DA converter output, through the order wire of cable or plug 1 communicate by letter with host computer or secondary instrument (referring to accompanying drawing 2).
Be described further below in conjunction with the accompanying drawing example illustrated.Fig. 1 is the structural drawing of the utility model sensor one example, and Fig. 2 is the utility model sensor circuit structured flowchart, and Fig. 3 is an embodiment circuit structure diagram, and Fig. 4 is split type sensor construction figure.
The overcoat 9 of sensor probe shown in Figure 1 is on the upper end cover of making to insulating material by spiral marking connection 2, inner core 5 upper ends are press fit into the bottom of upper end cover 2 through O-ring seal 3, and make by dog screw 6 and to measure circumferentially location and realize measuring the utmost point and the connections that are press fit into the measurement utmost point terminals 6A of the circuit board 7 on the upper end cover 2 with screw 4 of utmost point inner core 5 and upper end cover 2.The equipotential driving stage 8 of table is the ambroin copper clad plate making that is covered with the nickel plating Copper Foil with one side in the inner core, and plastic cover is contained in sticker measures on the utmost point inside surface, Copper Foil is towards circuit board 7, and the circuit board periphery is designed to the terminal of equipotential driving stage, again with scolding tin and 8 welding of equipotential driving stage.Be pressed with insulation sleeve 11 between the inside and outside sleeve lower end, corresponding seal 10 and 13 are housed in its inside surface and the lower surface groove, the bottom end cover of making of non-corrosive metal (NCM) 14 connects by screw thread and overcoat, is installed in to temperature sensing element 12 expressions the lower central of bottom end cover 14.It is that uniform some air vents are realized on the periphery of relevant position, overcoat two ends that inner/outer tube inner room ring cavity upper and lower side is communicated with extraneous duct.
Sensor circuit by outside 7.5-15V DC power supply, is received the input end VDD of power circuit 71 through plug 1.Power circuit 71 is formed positive stabilized voltage supply VCC by positive adjustable stabilized voltage supply integrated circuit N4, capacitor C19, C20, and its positive input terminal VDD patches the power lead P of headstock, and ground wire GND patches the ground wire G of headstock.Power circuit 71 also contains by switching power supply regulator integrated circuit N5, the negative stabilized voltage supply VSS that capacitor C21-C23, resistance R 31, inductance L 1, diode V1 form, the output VCC of the positive stabilized voltage supply of its input termination.
The PWM controller output of single chip circuit 72, the stabilized frequency that is obtained by its crystal oscillator frequency division is f0=2048-8192Hz, amplitude equals VCC receives carrier signal circuit 73 to the symmetrical square wave on ground input resistance R8.Carrier signal circuit 73 contains amplifier N1:B, resistance R 7, R8, capacitor C 30.The negative input end of amplifier N1:B meets input resistance R8, its positive input terminal ground connection, and negative input end also connects output terminal through R7, C30 parallel circuit.Output frequency equals f0's, and phase place is the triangular signal UI of the square wave quadrature lagging of input.
The triangular signal UI of carrier wave input end ZB connection circuit 73 outputs of carrier system metering circuit 74, carrier system metering circuit 74, temperature measuring circuit 78 contain amplifier NO:A--NO:D, temperature sensor V2, resistance R 9--R15, capacitor C 8--C14.Positive supply pin 4 pin of amplifier N0 meet VCC, negative supply pin 11 pin meet VSS, the triangular wave carrier signal of input connects 3 pin and the resistance R 9 of N0:A through capacitor C 10, the other end ground connection of R9,2 pin of NO:A connect 1 pin through R10,2 pin are also received 5 pin of equipotential driver follower N0:B, with through capacitor C 12, measure utmost point terminals 6A, dog screw 6 connects measures the utmost point 5,6 pin of NO:B connect 7 pin, 7 foot meridian capacitor C13, terminal D receives equipotential driving stage 8,1 foot meridian capacitor C11 and connects 10 pin, 10 pin are through R11 ground connection, 9 pin connect 8 pin and connect 14 pin through resistance R 14 through resistance R 15, and 14 pin connect 13 pin through resistance R 13 and capacitor C 14 parallel circuits, and 13 pin meet positive supply VCC through resistance R 12; 13 pin also connect the anode of thermometric device V2, and the negative terminal of V2 meets negative supply VSS, 12 pin ground connection.Amplifier N0:B in the circuit makes equipotential to drive follower, follow and will do measurement utmost point signal that electric current amplifies and receive the equipotential driving stage 8 of probe through capacitor C 13 and terminal D, reach and make the converter circuit of measuring in 5 pairs of probes of the utmost point because of the idiostatic isolation distribution-free electric capacity of equipotential driving stage 8 is arranged, thereby overcome interference, there is capacitor C X and only current potential is equaled 0 ground electrode 5, to realize measuring the purpose of air moisture content.And V2, N0:D, R12, R13, C14 constitute temperature measuring circuit 78.Simultaneously temperature direct current signal and humidity AC signal are dealt with in order to save transmission line and shared amplifier, so the output of temperature measuring circuit is transported to negative input end 9 pin of amplifier N0:C through resistance R 14, by the shunt voltage negative-feedback amplifier of forming with R15, N0:C temperature signal is done anti-phase amplification and export.Amplification coefficient is: KW=-R15/R14.The humidity AC signal then enters from positive input terminal 10 pin of amplifier N0:C, exchanges amplification coefficient to be: KJ=1+R15/R14.The signal that is applied is from the 8 pin output of N0:C.
The AC portion of output signal is the function of a complex variable of triangular wave and square wave stack.Its solid part signal is a triangular wave, and phase place is than PWM square wave quadrature lagging, and its value is proportional to feedback resistance R10 and adds 1 with the ratio of measuring utmost point leakage resistance RX over the ground and take advantage of carrier signal amplitude UI; Its imaginary signals is a square wave, phase place and pwm signal homophase, and its value equals carrier signal amplitude UI and multiply by the capacitive reactance of feedback resistance than measured capacitance.Total output voltage XH is:
XH＝KJ·UI(1+R10/RX)+UI(j·ω·CX·R10)
Imaginary signals separation circuit 75 contains D4, N1:A, R16-R19, C15.D4 uses CD4053, and N1:A uses low imbalance high speed amplifier, and it is connected to: the termination voltage signal XH of C15, another termination is as 1,5 pin of the D4 of phase-sensitive detector (PSD), D4 2,3,6,11-14 pin ground connection, 9,10 pin connect with reference signal UK frequently, 7 pin meet VSS, 8 pin ground connection, and 16 pin meet VCC, 15 pin meet R16,3 pin of another termination of R16 N1:A, 3 pin are through R17 ground connection, and 4 pin of D4 connect 2 pin of N1:A through R18,2 pin also connect 1 pin through R19, separate the imaginary signals UJ that obtains and export from 1 pin.And R17/R16=R19/R18=KX arranged.C15 is strobed into this circuit with the alternation composition among the XH and carries out phase sensitive detection, the effective constituent of output be among the XH with the absolute value UJ of the square wave of PWM homophase part.
UJ=UI ω CXR10KX is arranged.
The utility model causes measured capacitance CX magnitude variations to realize the related physical quantity measurement by the variation of detection probe electric capacity two interpolar air dielectric water cut (humidity).Measured capacitance value CX and voltage U J are made of corresponding two parts in the following formula.But what we paid close attention to should be that air humidity causes the pairing that part of voltage increment UU of measured capacitance increment CU that the medium change in dielectric constant causes only, and should be rejected (deducting) much larger than the pairing voltage U C of the original intrinsic capacitance CC of measured capacitance (the probe capacitor in the circuit is in the electric capacity in the dry air) of above-mentioned capacitance increase for its value, to improve measuring accuracy.
Above-mentionedly respectively measure corresponding following relation: the CX=CU+CC that has
UJ=UU+UC wherein
UU＝UI·ω·CU·R10·KX
UC＝UI·ω·CC·R10·KX
As seen UU, UC are a voltage that is proportional to UI.But UC is an amount more much bigger than UU.If the UI instability will influence the stable of UC.So, then can bring subtraction output that very mistake is arranged if substitute UC with stable VCC dividing potential drop.Should be transformed to DC voltage as the subtrahend in the subtracter through linearity with carrier voltage UI.
Filtering is amplified subtraction circuit 76 and is contained N3:A, N3:B, R20-R24, pot RP1, capacitor C 16.The output signal U J of imaginary signals separation circuit 75 enters the integration low-pass filter of the shunt voltage negative-feedback amplifier formula that is made of R22-R24, N3:B, C16, RP1 by R24, so that the alternation composition filtering in all processed signal voltages is kept flip-flop.
According to the analysis of last paragraph, this circuit amplifies the back as subtrahend with the negative ripple triangular wave UI of carrier signal generator output through amplifier N3:A, enters filtering amplification subtracter by RP1, R22.Be in the dry air in sensor, regulate RP1, make the voltage JF=0 of N3:B output, corresponding air moisture content equals 0.When sensor is in the soft air, the negative voltage of a reflection of N3:B output air moisture content.
Single-chip microcomputer is after recording temperature T and air moisture content U, table look-up or iterative computation draws corresponding saturation of the air absolute drift J, calculate relative humidity UX=(U/J) 100%RH then and calculate the temperature that the saturated aqueous rate equals current air moisture content, export as the dew point forecast parameter.
In order to reduce the probe diameter of integral sensor, can only carrier system metering circuit 74 and temperature measuring circuit 78 be contained on the circuit board 7, and other circuit are connected by cable connector, be contained in another miniature instrument casing, become a split type sensor (see figure 4).Even also whole circuit all can be contained in the instrument case, but instrument case should be connected with edge connector nearby with probe, and the cancellation cable becomes a Contiuum type sensor to reduce the wiring capacitance interference.At this moment, even can cancel equipotential driving stage 8 and interlock circuit.
Claims (6)
1. the wet quick Multifunction Sensor of a condenser type, contain the wet quick probe of condenser type and with the sensor circuit of probe associated working, described probe is characterized in that containing with core insulation and is linked in, bottom end cover (2,14) inner core between (5) and overcoat (9), in, outer jacket casing (5,9) make by erosion-resisting metal material, constitute the measurement utmost point and the ground electrode of wet quick probe electric capacity respectively, be provided with to insulation equipotential driving stage (8) on the inside surface of inner core (5), sensor circuit board (7) quilt hermetically, and to realize that with above-mentioned electrode the mode of corresponding connection is installed in the inner core (5), the central portion of upper end cover (2) is provided with circuit board 7 and realizes cable or the socket (1) that respective electrical connects, one temperature sensing element (12) expression that respective electrical connects is arranged is installed in the probe suitable position with circuit board, on the annular cavity that is made of the inner core overcoat, there is the duct that is in communication with the outside at following two ends; Described sensor circuit is characterized in that containing carrier signal generation circuit (73), carrier system metering circuit (74) and imaginary signals separation circuit (75), measured capacitance CX one utmost point ground connection, another utmost point access carrier formula metering circuit (74), carrier signal generation circuit (73) the generation constant amplitude triangular wave carrier signal UI of frequency surely is transported to carrier system metering circuit (74), metering circuit (74) output is by the solid part signal of the leakage resistance decision of carrier wave and measured capacitance and the complex signal that is synthesized by the imaginary signals of measured capacitance decision, be transported to imaginary signals separation circuit (75) respectively with the same frequency square-wave signal UK of another and UI phase differential 90 degree, imaginary signals separation circuit (75) then can be exported the electric signal UJ that is proportional to measured capacitance, a kind of like this being called " imaginary part method capacitive detection circuit "; In addition, sensor circuit also contains the power circuit (71) that positive and negative stabilized voltage supply VCC, VSS can be provided to each circuit, single chip circuit (72), and subtracter (76), amplifier (77), temperature measuring circuit (78) are amplified in filtering; Frequency f of PWM controller output of single chip circuit (72) is stable, amplitude stabilization equals VCC and receives carrier signal generation circuit (73) to the symmetrical square wave on ground, the electric signal UO of imaginary signals separation circuit (75) output connects filtering and amplifies subtracter (76), filtering is amplified subtracter (76) output through the signal of the calibrate signal that is proportional to air moisture content after amplifier (77) amplifies again, and the temperature voltage signal of temperature measuring circuit (78) output is received the corresponding interface of single chip circuit (72), the temperature that single-chip microcomputer records with digital quantity and/or analog quantity output, information such as humidity.
2. by the wet quick Multifunction Sensor of the described condenser type of claim 1, it is characterized in that making and measure circumferentially location of utmost point inner core (5) and upper end cover (2), and realize measuring the connection of the measurement utmost point terminals (6A) on the utmost point and the circuit board (7) that is press fit into screw (4) on the upper end cover (2) by dog screw (6); The equipotential driving stage (8) of table is the ambroin copper clad plate making that is covered with Copper Foil with one side in the inner core, and the plastic cover sticker measured on the utmost point inside surface, Copper Foil is towards circuit board (7), and the circuit board periphery is designed to the terminal of equipotential driving stage, with scolding tin and equipotential driving stage (8) welding.
3. by claim 1, the wet quick Multifunction Sensor of 2 described condenser types, it is characterized in that carrier system metering circuit (74), temperature measuring circuit (78) contain amplifier N0:A-N0:D, resistance R 9-R15, capacitor C 10-C14, wherein, V2, N0:D, R12-R15 constitute temperature measuring circuit (78); Positive supply pin 4 pin of amplifier N0 meet VCC, negative supply pin 11 pin meet VSS, the triangular wave carrier signal of input connects 3 pin and the resistance R 9 of N0:A through capacitor C 10, the other end ground connection of R9,2 pin of N0:A connect 1 pin through R10,2 pin are also received 5 pin of equipotential driver follower N0:B, with through capacitor C 12, measure utmost point wiring termination and measure the utmost point 5,6 pin of N0:B connect 7 pin, 7 foot meridian capacitor C13, terminal D receives equipotential driving stage 8,1 foot meridian capacitor C11 and connects 10 pin, 10 pin are through R11 ground connection, 9 pin connect 8 pin and connect 14 pin through resistance R 14 through resistance R 15, and 14 pin connect 13 pin through resistance R 13 and capacitor C 14 parallel circuits, and 13 pin meet positive supply VCC through resistance R 12; 13 pin also connect the anode of thermometric device V2, and the negative terminal of V2 meets negative supply VSS, 12 pin ground connection; Imaginary signals separation circuit (75) contains D4, N1:A, R16-R19, C15, D4 uses CD4053, N1:A uses low imbalance high speed amplifier, it is connected to: the termination voltage signal XH of C15, another termination is as 1 of the D4 of phase-sensitive detector (PSD), 5 pin, 2 of D4,3,6,11-14 pin ground connection, 9,10 pin connect with frequency reference signal UK, 7 pin meet VSS, 8 pin ground connection, 16 pin meet VCC, and 15 pin meet R16,3 pin of another termination of R16 N1:A, 3 pin are through R17 ground connection, and 4 pin of D4 connect 2 pin of N1:A through R18, and 2 pin also connect 1 pin through R19, separate the imaginary signals UJ that obtains and export, and R17/R16=R19/R18=KX is arranged from 1 pin.
4. by the wet quick Multifunction Sensor of the described condenser type of claim 3, it is characterized in that filtering amplification subtraction circuit (76) contains N3:A, N3:B, R20-R24, pot RP1, capacitor C 16, the output signal U J of imaginary signals separation circuit (75) enters the integration low-pass filter of the shunt voltage negative-feedback amplifier formula that is made of R22 ￣ R24, N3:B, C16, RP1 by R24, the negative ripple triangular wave UI of carrier signal generator output as subtrahend, enters filtering by RP1, R22 and amplifies subtracter after amplifier N3:A amplifies; Amplifier circuit (77) contains N2:B, N2:C, resistance R 25-R30, RP2, capacitor C 17, C18; Wherein, the N2:B circuit is the water cut amplifying circuit, enter negative terminal 6 pin of N2:B through R25 from the voltage JF of the sign water cut of N3:B, eliminate ripple component through anti-phase amplification and integration low-pass filtering, regulate amplification quantity by RP2, be suitable for the voltage X1 that single chip circuit AD transducer is gathered with certain proportion output, deliver to 2 pin of single-chip microcomputer through current-limiting protection resistance R 27; The N2:C interlock circuit is the temperature signal amplifier; import negative terminal 9 pin of N2:C through R28 by the superposed signal of metering circuit (74) output; do anti-phase amplification; and filtering alternation composition; output in certain proportion is suitable for the voltage VW that single chip circuit AD transducer is gathered, and delivers to 4 pin of single-chip microcomputer through current-limiting protection resistance R 30.
5. by claim 1, the wet quick Multifunction Sensor of 2 or 4 described condenser types, it is characterized in that only carrier system metering circuit (74) and temperature measuring circuit (78) being contained on the circuit board (7), and other circuit are connected by cable connector, be contained in another miniature instrument casing, become a split type sensor.
6. by the wet quick Multifunction Sensor of the described condenser type of claim 3, it is characterized in that only carrier system metering circuit (74) and temperature measuring circuit (78) being contained on the circuit board (7), and other circuit are connected by cable connector, be contained in another miniature instrument casing, become a split type sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99213978 CN2387537Y (en) | 1999-06-24 | 1999-06-24 | Capacity type wet sensitive multifunctional sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99213978 CN2387537Y (en) | 1999-06-24 | 1999-06-24 | Capacity type wet sensitive multifunctional sensor |
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| Publication Number | Publication Date |
|---|---|
| CN2387537Y true CN2387537Y (en) | 2000-07-12 |
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ID=34006259
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 99213978 Expired - Lifetime CN2387537Y (en) | 1999-06-24 | 1999-06-24 | Capacity type wet sensitive multifunctional sensor |
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| Country | Link |
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| CN (1) | CN2387537Y (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101403718B (en) * | 2008-10-24 | 2012-06-13 | 深圳和而泰智能控制股份有限公司 | Method for detecting ambient humidity by utilizing single-chip port and single-chip |
| CN104634855A (en) * | 2015-02-03 | 2015-05-20 | 广东美的制冷设备有限公司 | Household appliance humidity detecting method and household appliance humidity detecting device |
| CN104807481A (en) * | 2015-04-23 | 2015-07-29 | 天津大学 | Triangular wave excited impedance type sensor measuring circuit |
| CN108896623A (en) * | 2018-07-11 | 2018-11-27 | 西南交通大学 | It is a kind of for measuring the numerical frequency formula humidity sensor of gas relative humidity |
| CN109738488A (en) * | 2019-02-20 | 2019-05-10 | 中国科学院过程工程研究所 | A kind of reed-type probe being conveniently replaceable needle section |
| CN111492234A (en) * | 2018-11-09 | 2020-08-04 | 广东美的白色家电技术创新中心有限公司 | Movable electric device |
| CN116203084A (en) * | 2023-02-09 | 2023-06-02 | 广州海谷电子科技有限公司 | Method for realizing humidity-sensitive capacitance sensor based on switch capacitance measurement and sensor |
-
1999
- 1999-06-24 CN CN 99213978 patent/CN2387537Y/en not_active Expired - Lifetime
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101403718B (en) * | 2008-10-24 | 2012-06-13 | 深圳和而泰智能控制股份有限公司 | Method for detecting ambient humidity by utilizing single-chip port and single-chip |
| CN104634855A (en) * | 2015-02-03 | 2015-05-20 | 广东美的制冷设备有限公司 | Household appliance humidity detecting method and household appliance humidity detecting device |
| CN104807481A (en) * | 2015-04-23 | 2015-07-29 | 天津大学 | Triangular wave excited impedance type sensor measuring circuit |
| CN104807481B (en) * | 2015-04-23 | 2017-06-13 | 天津大学 | A kind of impedance based sensor measuring circuit of triangle wave excitation |
| CN108896623A (en) * | 2018-07-11 | 2018-11-27 | 西南交通大学 | It is a kind of for measuring the numerical frequency formula humidity sensor of gas relative humidity |
| CN108896623B (en) * | 2018-07-11 | 2020-01-31 | 西南交通大学 | digital frequency type humidity sensor for measuring relative humidity of gas |
| CN111492234A (en) * | 2018-11-09 | 2020-08-04 | 广东美的白色家电技术创新中心有限公司 | Movable electric device |
| US12042106B2 (en) | 2018-11-09 | 2024-07-23 | Guangdong Midea White Home Appliance Technology Innovation Center Co., Ltd. | Movable electronic apparatus |
| CN109738488A (en) * | 2019-02-20 | 2019-05-10 | 中国科学院过程工程研究所 | A kind of reed-type probe being conveniently replaceable needle section |
| CN116203084A (en) * | 2023-02-09 | 2023-06-02 | 广州海谷电子科技有限公司 | Method for realizing humidity-sensitive capacitance sensor based on switch capacitance measurement and sensor |
| CN116203084B (en) * | 2023-02-09 | 2024-01-23 | 广州海谷电子科技有限公司 | Method for realizing humidity-sensitive capacitance sensor based on switch capacitance measurement and sensor |
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