CN207181349U - Gas concentration measuring apparatus and air purifier - Google Patents
Gas concentration measuring apparatus and air purifier Download PDFInfo
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- CN207181349U CN207181349U CN201721258359.4U CN201721258359U CN207181349U CN 207181349 U CN207181349 U CN 207181349U CN 201721258359 U CN201721258359 U CN 201721258359U CN 207181349 U CN207181349 U CN 207181349U
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Abstract
The utility model discloses a kind of gas concentration measuring apparatus and air purifier, the device includes：Sensor cluster, it includes the sensor and load resistance that can be connected in a series arrangement, for connecting the input terminal of voltage source, for exporting the lead-out terminal of the sensor cluster electric signal；By loading at least the first predetermined voltage and the second predetermined voltage to the sensor cluster input terminal respectively, the first electric signal corresponding to the lead-out terminal and the second electric signal are received, and the controller of gas concentration is determined based on first electric signal and the second electric signal.Gas concentration measuring apparatus and air purifier provided by the utility model, Zero drift in main amplifier can be overcome, reduce humiture interference, so as to obtain accurate, reliable gas concentration measurement, improve Consumer's Experience.
Description
Technical field
Detection of gas field is the utility model is related to, more particularly to a kind of gas concentration measuring apparatus and air purifier.
Background technology
At present, researcher studies to indoor air quality, and all interiors that generally sampling analysis is obtained can
Important finger of the summation of volatile organic matter (VOC Volatile Organic Compound) as evaluation indoor air quality
Mark.Wherein, various measured VOC are generically and collectively referred to as volatile total organic matter (TVOC Total Volatile Organic
Compound), it includes：All C-H compounds such as alcohol, aldehyde, benzene, ketone and alkane.
When the VOC excessive concentrations under the environment such as relatively closed interior, in-car, it is easy to cause human body acute poisoning,
The symptoms such as headache, dizziness, cough, Nausea and vomiting occur in the lighter；Twitch occurs when serious, and can hurt people liver,
Kidney, brain and and nervous system.At present, in order to accurately understand the VOC concentration under current environment, VOC sensors are generally passed through
Measure.Further, in order to improve the accuracy of measurement, the signal that can may be also obtained based on VOC sensors carries out school
Just, VOC gas concentration is finally exported.
However, null offset easily occurs during long-term use for VOC sensors at present, and then influence the accurate of measurement
Property, or even user can be misled.For example, under a specific scene, when the Zero drift in main amplifier of VOC sensors is very tight
During weight, cause the concentration value of reality output much smaller than actual concentration value.And the user under current environment sees VOC concentration
It is relatively low, it is more likely that vigilance to be reduced, so as to improve the risk of poisoning.In addition, after null offset occurs in sensor, i.e.,
Make the follow-up correct operation of carry out, due to being unknown as the benchmark of zero point, it is corrected also in default of according to without reality
Border meaning, it is impossible to fundamentally improve measurement accuracy.
Therefore, it is necessary to a kind of new gas concentration measurement technology is proposed, to overcome existing sensor using process
The Zero drift in main amplifier of middle appearance, humiture interference is reduced, measurement accuracy is improved, so as to provide a user accurate, reliable gas
Bulk concentration measured value.
Utility model content
The purpose of this utility model is to provide a kind of gas concentration measuring apparatus and air purifier, zero point can be overcome to float
Shifting problem, so as to obtain accurate, reliable gas concentration measurement, improve Consumer's Experience.
Above-mentioned purpose of the present utility model can be realized using following technical proposal：
A kind of gas concentration measuring apparatus, including：
Sensor cluster, it includes the sensor and load resistance that can be connected in a series arrangement, for connecting voltage source
Input terminal, for exporting the lead-out terminal of the sensor cluster electric signal；
By loading at least the first predetermined voltage and the second predetermined voltage to the sensor cluster input terminal respectively, connect
The first electric signal corresponding to the lead-out terminal and the second electric signal are received, and it is true based on first electric signal and the second electric signal
Determine the controller of gas concentration.
Further, the sensor cluster also includes：Include the different first resistor of at least two resistances and the second electricity
The resistance collection of resistance, the load resistance are the resistance lumped resistance value and the immediate resistance of the current resistance of the sensor.
Further, the sensor and load resistance are in series, and the lead-out terminal is used to obtain the sensor two
The analog voltage signal at end or the analog voltage signal at the load resistance both ends.
Further, first electric signal or the second electric signal are the analog voltage signal；
The gas concentration measuring apparatus also includes the change-over circuit that the analog voltage signal is converted to data signal,
The change-over circuit is electrically connected with the lead-out terminal of the sensor cluster and the controller respectively.
Further, in addition to：First voltage source and the second voltage source, and be electrically connected with and can cut with the controller
Change the switch unit that the first voltage source or the second voltage source are connected with the input terminal.
Further, in addition to：It can be connected with the input terminal and first can be provided to the sensor cluster and made a reservation for
The voltage source of voltage and the second predetermined voltage.
Further, the sensor cluster sets having heaters, is carried in the first predetermined electricity of the sensor cluster
Pressure or the second predetermined voltage are the heating voltage being carried on the heater, and the sensor cluster is additionally provided with for powering
Loop voltage, first predetermined voltage is more than or equal to the loop voltage, and second predetermined voltage is less than or equal to described
Loop voltage, first predetermined voltage are more than second predetermined voltage.
Further, first predetermined voltage is 1.4 times to 1 times of the loop voltage；Second predetermined voltage
For 0.5 times to 1 times of the loop voltage.
Further, the loop voltage is 5 volts, and for first predetermined voltage between 5 volts to 7 volts, described second is pre-
Voltage is determined between 2.5 volts to 5 volts, wherein, first predetermined voltage is more than second predetermined voltage.
Further, the load time scope of first predetermined voltage is 10 seconds to 60 seconds；Second predetermined voltage
Load time scope be 10 seconds to 60 seconds.
Further, in addition to the controller display being electrically connected with, for showing the gas concentration.
Further, in addition to the controller communication module being electrically connected with.
A kind of air purifier, the air purifier set any of the above-described described gas concentration measuring apparatus.
The technical scheme provided from above the application embodiment, gas concentration measurement provided herein dress
Put, during test, voltage source loads the first predetermined voltage to the input terminal, and after loading the scheduled time, controller can receive
First electric signal of the lead-out terminal output.Then, voltage source loads the second predetermined voltage to the input terminal, and loading is pre-
After fixing time, controller can receive the second electric signal of the lead-out terminal output.In addition, it can be stored in the controller
There is the response curve of the sensor.During controller data processing, first electric signal, the second electric signal are substituted into sensor
Response curve, it may be determined that go out the absolute concentration of current gas, eliminate Zero drift in main amplifier, overcome the shadow of temperature and humidity
Ring, so as to obtain accurate, reliable gas concentration measurement, improve Consumer's Experience.
Brief description of the drawings
Fig. 1 is the module diagram for the gas measurement device that one embodiment of the application provides；
Fig. 2 is the main circuit diagram for the gas measurement device that one embodiment of the application provides；
Fig. 3 is the structural representation for the sensor cluster that one embodiment of the application provides；
Fig. 4 is the response curve of the sensor after a kind of nonlinear fitting provided in one embodiment of the application；
Fig. 5 is the response curve of the sensor after a kind of sectional linear fitting provided in one embodiment of the application；
Fig. 6 be one embodiment of the application provide by the two bar response curves that are obtained under 5v and 3.3v heating voltages
Construct the new graph of relation of sensor；
Fig. 7 is the step flow chart for the gas measuring method that one embodiment of the application provides；
Fig. 8 is the step flow chart for the gas measuring method that one embodiment of the application provides；
Fig. 9 is the constant temperature that the gas measurement device that one embodiment of the application provides is carried out under 700ppbVOC concentration
The curve that constant humidity obtains with the contrast experiment that alternating temperature is got wet；
Figure 10 is the constant temperature that the gas measurement device that one embodiment of the application provides is carried out under 950ppbVOC concentration
The curve that constant humidity obtains with the contrast experiment that alternating temperature is got wet；
Figure 11 is the indoor test pair of gas concentration measuring apparatus and existing PID that one embodiment of the application provides
Than result curve figure.
Description of reference numerals：
Sensor cluster -31；Change-over circuit -32；Controller -33；Voltage control circuit -34；Communication module -35；Display
Device -36；Sensor-Q2；Variable resistor-RS；Load resistance-RL；Input terminal -22；Lead-out terminal -24；Heater -23；Monolithic
Machine-U6.
Embodiment
Below in conjunction with the drawings and specific embodiments, the technical solution of the utility model is elaborated, it should be understood that this
A little embodiments are merely to illustrate the utility model rather than limitation the scope of the utility model, read the utility model it
Afterwards, modification of the those skilled in the art to the various equivalent form of values of the present utility model each falls within the application appended claims and limited
In fixed scope.
It should be noted that when element is referred to as " being arranged at " another element, it can be directly on another element
Or there may also be element placed in the middle.When an element is considered as " connection " another element, it can be directly connected to
To another element or it may be simultaneously present centering elements.Term as used herein " vertical ", " horizontal ", " on ",
" under ", "left", "right" and similar statement for illustrative purposes only, it is unique embodiment to be not offered as.
Unless otherwise defined, all of technologies and scientific terms used here by the article and the technical field of the application is belonged to
The implication that technical staff is generally understood that is identical.The term used in the description of the present application is intended merely to description tool herein
The purpose of the embodiment of body, it is not intended that in limitation the application.
The utility model provides a kind of gas concentration measuring apparatus and air purifier, can overcome Zero drift in main amplifier,
So as to obtain accurate, reliable gas concentration measurement, Consumer's Experience is improved.
Fig. 1, Fig. 2 and Fig. 3 are referred to, a kind of gas concentration measuring apparatus provided in the application embodiment can wrap
Include：Sensor cluster 31, it includes the sensor Q2 that can be connected in a series arrangement and load resistance RL, for connecting voltage source
Input terminal 22, for exporting the lead-out terminal 24 of the electric signal of sensor cluster 31；By respectively to the input terminal
22 loading at least the first predetermined voltages and the second predetermined voltage, receive the first electric signal and second that the lead-out terminal 24 exports
Electric signal, and determine based on first electric signal and the second electric signal the controller 33 of gas concentration.
In the present embodiment, the sensor Q2 can be used for the concentration signal for obtaining predetermined gas, such as TVOC
Concentration signal.According to differences such as type and purposes, responses of the sensor Q2 for gas with various is also different.
Specifically, the type of the sensor Q2 can be semiconductor type sensor, or catalytic combustion-type senses
Device etc..Certainly, the type of the sensor Q2 is not limited to the example above, can be extended to other kinds of sensor, this
Specific limit is not made in application herein.In the present embodiment, mainly with cost it is relatively low, last a long time but it is long-term use of easily
Occur illustrating exemplified by the semiconductor transducer of null offset.For example, for the semiconductor transducer of electrical response type,
It is provided with the variable resistor R that resistance changes with gas concentrationSWith heater 23.Specifically, variable resistor RSResistance with it is current
The concentration of gas is bigger into inversely related, i.e. gas concentration, and sensor Q2 electrical conductivity is higher, variable resistor RSResistance get over
It is small；Gas concentration is with regard to smaller, and sensor Q2 electrical conductivity is with regard to smaller, sensor Q2 variable resistors RSResistance it is bigger.
As shown in figure 3, for gas sensor Q2, it has heating voltage VHWith loop voltage VC.Heating voltage VH
Integrated heater 23 is applied to for maintaining the specified temp that sensitive sub-prime is in object gas is adapted.Wherein,
Sensitive sub-prime can be made up of basic heater 23 and the metal-oxide semiconductor (MOS) formed on aluminum oxide substrate.Specifically
, it is to be carried on the heater 23 to be carried in the first predetermined voltage of the sensor cluster 31 or the second predetermined voltage
Heating voltage VH.Loop voltage VCFor powering, specifically, may be used to provide by sensor Q2 and load resistance RLIt is in series
Both end voltage on the sensor cluster 31 of formation.Wherein, loop voltage VCThere is provided by dc source.Meeting sensor Q2's
On the premise of electrical requirements, the heating voltage VHWith loop voltage VCA power circuit can be shared.Wherein, gas sensing
Device Q2 includes four interfaces, interface (1,2,3,4).Wherein, interface (1,4) is used to load the heating voltage VH.That is,
The interface (1,4) can be used as input terminal 22.Interface 3 coordinates ground connection to can be used for loading the loop voltage VC。
For each gas sensor Q2, sensor Q2 outputs response corresponding with existing between gas concentration is bent
Line.After linear or nonlinear fitting is carried out to sensor Q2 response curve, can obtain sensor Q2 primary signals with
Corresponding relation between gas (such as VOC) concentration.
Specifically, under measuring state, the load resistance RLIt can be in series with the sensor Q2.Due to the biography
The variable resistor R of sensor Q2 in itselfSPartial pressure and gas concentration inversely related, in total loop voltage VCOn the premise of certain, with institute
State the load resistance R of sensor Q2 series connectionLPartial pressure and gas concentration positive correlation.Further, when defeated to the sensor Q2
Go out between gas concentration after being fitted processing in the presence of corresponding response curve, it may be determined that go out and connected with the sensor Q2
Load resistance RLPartial pressure and gas concentration between corresponding relation.For example, after taking sectional linear fitting to handle, can obtain
Obtain the load resistance RLPartial pressure and gas concentration between linear relationship.
As shown in figure 4, when the response curve to sensor Q2 uses nonlinear fitting, the sensor Q2 primary signals
Between VOC concentration is in unitary high-order moment relation.Wherein, ordinate represent gas concentration, unit be microgram/cube
Rice (ug/m3)；Abscissa represents the original analog value of sensor Q2 outputs.
As shown in figure 5, when the fitting (linear) using segmented linear of the response curve to sensor Q2, by VOC concentration
Interval division is 0-0.3mg/m3(milligram/cubic meter), 0.3-3mg/m3, 3-10mg/m3.Obtain three sections of original letters of sensor Q2
Number output and the linear relationship of VOC concentration.Wherein, ordinate represents gas concentration, and unit is microgram/cubic meter (ug/m3)；It is horizontal
Coordinate representation sensor Q2 original analogs export.
In the present embodiment, the input terminal 22 is used to connect voltage source.When voltage source is connected with input terminal 22
Afterwards, it is possible to achieve the first predetermined voltage, the second predetermined voltage are respectively loaded on the sensor cluster 31.Specifically, work as institute
When the sensor stated in sensor cluster 31 is sensor Q2 as shown in Figure 2, the input terminal 22 can be sensor Q2
Interface (1,4), so as to by different heating voltage VHIt is loaded onto sensor Q2 both ends.
Wherein, first predetermined voltage is more than or equal to the loop voltage VC, second predetermined voltage is less than or equal to
The loop voltage VC, first predetermined voltage is more than second predetermined voltage.Specifically, first predetermined voltage is
The loop voltage VC1.4 times to 1 times；Second predetermined voltage is the loop voltage VC0.5 times to 1 times.
In a specific embodiment, as the loop voltage VCFor 5V (volt) when, first predetermined voltage can
It is some voltage between 5 volts to 7 volts between 5 volts to 7 volts.Second predetermined voltage can 2.5 volts to 5 volts it
Between, it is some voltage between 2.5 volts to 5 volts.
It is found through experiments that：Characteristics of the sensor Q2 under different heating voltages has corresponding change.The application institute
For sensor cluster 31, its give tacit consent to heating voltage be constant 5V.In order that two on-load voltage value (the first predetermined electricity
Pressure, the second predetermined voltage) there is obvious difference, when the first predetermined voltage is arranged into the loop voltage VC1.4 times
To 1 times, i.e., in the range of 5V to 7V, both ensured sensor Q2 the first scheduled voltage apparently higher than the second predetermined voltage
Value, can also make sensor cluster 31 be unlikely to because heating voltage is too high and caused by damage.Second predetermined voltage is arranged to institute
State loop voltage VC0.5 times to 1 times, i.e., when in the range of 2.5V-5V, because working as heating voltage VHDuring less than 2.5V, sensing
Response will not be produced to VOC, while make second voltage no more than 5V to ensure sensor Q2 height after device Q2 operating temperatures are too low
Low two heating voltage VHIt is unlikely to be too close to and is unable to reach expected effect.
Preferably, first predetermined voltage can be 5 volts, and second predetermined voltage can be 4 volts.When described first
Predetermined voltage is 5 volts, and second predetermined voltage can improve responses of the sensor Q2 to the aromatics such as toluene VOC when being 4 volts.
In one embodiment, first predetermined voltage, the second predetermined voltage can be provided by same voltage source.Tool
Body, the voltage source can be the voltage source that can provide different voltage swings.The voltage source and the electricity of controller 33
Property connection, by the voltage control circuit 34 controller 33 can be realized to the voltage source output control signal.Specifically,
The control signal can be data signal, or analog signal, specific the application do not make specific limit herein.
For example, the control signal is data signal：1 or 0.When the controller 33 output 1, the voltage source is to the sensor
The first higher predetermined voltage of the output voltage of component 31；When control output 0, the voltage source is to the sensor group
The second relatively low predetermined voltage of the output voltage of part 31.Specifically, the control voltage source of controller 33 is cut to sensor cluster 31
Changing the function of loading first predetermined voltage and the second predetermined voltage can specifically be realized by voltage control circuit 34, such as be schemed
Shown in 2, such as single-chip microcomputer U6 and necessary connection circuit realiration can be combined.
In addition, the voltage source can also be inputted different from first predetermined voltage, second to the input terminal 22
3rd predetermined voltage of predetermined voltage, or voltage of other scheduled voltages etc., specifically, the application does not make specifically herein
Limit.
In another embodiment, first predetermined voltage, the second predetermined voltage can be carried by different voltage sources
For.Specifically, the gas concentration measuring apparatus can include first voltage source and the second voltage source.The first voltage source can
For providing the first predetermined voltage to the input terminal 22, the second voltage source can provide to the input terminal 22
Second predetermined voltage.Receive the first voltage source, the input terminal 22 of the second voltage source can be two pairs of different terminals,
Can be same to terminal.
When the input terminal 22 of the reception first voltage source, the second voltage source is with a pair of end period of the day from 11 p.m. to 1 a.m, further, institute
Stating gas concentration measuring apparatus can also include the first voltage source or the are electrically connected with and can switched with the controller 33
The switch unit that two voltage sources are connected with the input terminal 22.The first voltage source or the second voltage source can be by described
Switch unit connects with the input terminal 22 interval.Specifically, the switch unit is electrically connected with the controller 33, energy
The control signal that the controller 33 is sent enough is received, and the first voltage source or the second electricity are connected according to the control signal
Potential source.Such as the control signal can be data signal, or analog signal, specific the application do not make to have herein
The restriction of body.For example, the control signal is data signal：1 or 0.When the controller 33 output 1, the switch unit
First voltage source is connected with the input terminal 22, the first predetermined electricity higher to the output voltage of sensor cluster 31
Pressure；When control output 0, the second voltage source is connected by the switch unit with the input terminal 22, to the sensing
The second relatively low predetermined voltage of the output voltage of device assembly 31.
In addition, the voltage source can also include can to the input terminal 22 input different from the first voltage source,
The tertiary voltage source of first predetermined voltage of the second voltage source offer, the 3rd predetermined voltage of the second predetermined voltage, or can provide
Voltage source of the voltage of other scheduled voltages etc., specifically, the application does not make specific limit herein.
In the present embodiment, the lead-out terminal 24 is used for the electric signal for exporting the sensor cluster 31.According to institute
It is different to state object or the position of the collection of lead-out terminal 24, the physical significance of the electric signal of the sensor cluster 31 of its corresponding output
It is different.When the lead-out terminal 24 gathers the load resistance RLDuring the electric signal at both ends, what the sensor cluster 31 exported
Electric signal is the load resistance RLVoltage division signal VL.When the lead-out terminal 24 gathers the sensor Q2 variable resistors RS
During the electric signal at both ends, the electric signal that the sensor cluster 31 exports is the variable resistor RSVoltage division signal.Certainly, institute
The object or position for stating the collection of lead-out terminal 24 are not limited to the example above, specifically, the application does not make specific limit herein
It is fixed.
In the present embodiment, the sensor cluster 31 is mainly using sensor Q2 and load resistance RLThe side of series connection
Formula, it is analog voltage signal that the electric signal is corresponding.In addition, the sensor cluster 31 can also use sensor Q2 with bearing
Mode in parallel etc. is carried, the electric signal can correspond to analog current signal.Certainly, according to the structure of sensor cluster 31
Difference, the connotation of the electric signal can be different, and the form of the electric signal is not limited to foregoing description, art technology
Personnel the application technical spirit enlightenment under, it is also possible to make other changes, but as long as its realize function and effect with
The application is same or similar, all should be covered by the application protection domain.
As the sensor Q2 and load resistance RLWhen being in series, first electric signal or the second electric signal are simulation electricity
Signal is pressed, the gas concentration measuring apparatus also includes the change-over circuit that the analog voltage signal is converted to data signal
32, the change-over circuit 32 is electrically connected with the lead-out terminal 24 and the controller 33 of the sensor cluster 31 respectively.
Wherein, the change-over circuit 32 is used to convert analog signals into data signal, specifically, it can include A/D
Change-over circuit 32, can also be including operational amplifier etc..When converting analog signals into digital letter using the change-over circuit 32
After number, the data signal after conversion is sent to controller 33 by the change-over circuit 32, and the controller 33 can enter to the signal
Row identification.
In addition, the change-over circuit 32 can also be integrated in the controller 33, the output end is by the simulation of acquisition
Signal is transferred to the controller 33, and the analog signal is first carried out digital-to-analogue conversion by the controller 33, then further
Identification is read and processing.
In the present embodiment, the controller 33 can first control voltage source it is first pre- to the input terminal 22 loading
Determine voltage, after loading the scheduled time, the first electric signal that the lead-out terminal 24 exports can be received.Then, control voltage source
The second predetermined voltage is loaded to the input terminal 22, after loading the scheduled time, can receive what the lead-out terminal 24 exported
Second electric signal.In addition, the response curve of the sensor Q2 can be stored with the controller 33.At the data of controller 33
During reason, first electric signal, the second electric signal are substituted into sensor Q2 response curve, it may be determined that go out the exhausted of current gas
To concentration, Zero drift in main amplifier is eliminated, reduces humiture interference, so as to obtain accurate, reliable gas concentration measurement, is improved
Consumer's Experience.
In one embodiment, the sensor cluster 31 can also include：Comprising at least two resistances it is different
The load matched resistance collection of one resistance and second resistance, the sensor Q2 are provided with variable resistor RS, the load resistance RLFor
The load matched resistance lumped resistance value and the variable resistor RSThe immediate resistance of current resistance.
For sensor cluster 31, as sensor Q2 variable resistors RSCurrency and load resistance RLResistance get over
Close, the precision that it is measured is higher.In the present embodiment, in order to ensure the measurement accuracy of gas concentration measuring apparatus, institute
Load matched resistance collection can be included by stating sensor cluster 31.The load matched resistance collection includes the resistance of multiple different resistances,
, will be with the variable resistor R when detectionSThe immediate resistance of current resistance as load resistance.Specifically, such as Fig. 2 institutes
Show, different circuits can be coordinated using single-chip microcomputer U6 pin, realize the institute between two input terminals 22 of heating voltage
Loop on set a variety of resistance to combine, so as to access the load resistance R of different resistancesL。
In one embodiment, the gas concentration measuring apparatus can also include being electrically connected with the controller 33
Display 36, for showing the gas concentration.
In the present embodiment, the gas concentration measuring apparatus is also provided with being electrically connected with the controller 33
Display 36, after the controller 33 determines current gas concentration, the display 36 can be transferred to and shown
Show.Wherein, the mode of the electric connection can be that wired connection can also be wireless connection, and specific the application is herein not
Make specific limit.In addition, the display 36 shows that the mode of the gas concentration can be shown in a manner of numeral or word
Show, can also the mode of figure show, various ways can also be used to combine and be shown, specifically, the application is herein not yet
Make specific limit.
In one embodiment, the gas concentration measuring apparatus can also include being electrically connected with the controller 33
Communication module 35.
In the present embodiment, the gas concentration measuring apparatus can also include what is be electrically connected with the controller 33
Communication module 35, the communication module 35 are used for sending and receiving for data.Specifically, the communication module 35 can be by described in
The gas concentration that controller 33 determines is transferred to other equipment.For example, the communication module 35 can pass gas concentration data
The memory for being defeated by specified location is stored, and can also be sent to the equipment with display function and be shown.The communication
The concrete form of module 35 can be WIFI module, bluetooth module, infrared module etc., or can also be other forms, specifically
, the application does not make specific limit herein.
A kind of air purifier is additionally provided in the application embodiment, the air purifier is provided with above-mentioned embodiment party
Gas concentration measuring apparatus described in formula.Specifically, the concrete structure of the gas concentration measuring apparatus forms and its can
The technique effect of realization is referred to the specific descriptions of above-mentioned embodiment, and the application will not be repeated here.
Referring to Fig. 7, a kind of gas concentration measuring method provided in the application embodiment may include steps of：
Step S10：The first predetermined voltage is loaded to sensor cluster, after first scheduled time, receives the sensor group
First electric signal of part output；
Step S12：The second predetermined voltage is loaded to the sensor cluster, after second scheduled time, receives the sensing
The second electric signal that device assembly 31 exports；
Step S14：Response curve based on sensor in the sensor cluster and first electric signal received, the
Two electric signals determine gas concentration.
In the present embodiment, it can combine and refer to device embodiments, the sensor cluster 31 can include：Sensing
Device Q2, the load resistance R that can be connected with the sensor Q2L, and for connecting the input terminal 22 of voltage source, for defeated
Go out the lead-out terminal 24 of the electric signal of sensor cluster 31.Specifically, to be referred to above-mentioned gas dense for the effect of all parts
The specific description of measurement apparatus embodiment is spent, the application will not be repeated here.In the present embodiment, described first is predetermined
Voltage, the second predetermined voltage are specially the heating voltage for being carried in sensor both ends, specifically, its loading position etc. refer to
The specific descriptions of gas concentration measuring apparatus embodiment are stated, the application will not be repeated here.In addition, the first electric signal and second
Electric signal also refer to the specific descriptions of above-mentioned gas apparatus for measuring concentration embodiment, and the application will not be repeated here.
Wherein, first scheduled time can be 10S (second) between 60S.When the described first pre- timing of heating
Between when being less than 10S, heating of the heating voltage to heater 23 may not get a desired effect, so as to influence sensor measurement
Precision.After first scheduled time is more than 60S, heater 23 is reliably heated, if now extending the heat time again
It is nonsensical.In addition, with the extension of heat time, the gas concentration under current environment is also constantly changing, if will
First scheduled time was configured long, can also influence measurement accuracy to a certain extent.To sum up, exist when first scheduled time
When 10S is between 60S, it can preferably ensure the measurement accuracy of sensor.Likewise, the setting of second scheduled time
Can also with reference to the setting of first scheduled time, be 10S between 60S, specific reason, repeat no more.
When carrying out gas concentration measurement on the basis of the gas concentration measuring apparatus, heating voltage can be first turned on
Preheated.Then formal gas concentration measurement is carried out.Then biography of the control voltage source of controller 33 to sensor cluster 31
Sensor loads the first predetermined voltage, after loading the scheduled time, can receive the first electric signal of the output of institute's sensor cluster 31.So
Afterwards, control voltage source loads the second predetermined voltage to the sensor of the sensor cluster 31, after loading the scheduled time, Ke Yijie
Receive the second electric signal that the sensor cluster 31 exports.In addition, the sensor can be stored with the controller 33
Response curve.During 33 data processing of controller, first electric signal, the second electric signal are substituted into the response curve of sensor,
Can determine the absolute concentration of current gas, eliminate Zero drift in main amplifier, reduce humiture interference, so as to obtain it is accurate, can
The gas concentration measurement leaned on, improves Consumer's Experience.
In one embodiment, the sensor cluster 31 includes：The electricity of the different resistances of sensor Q2 and at least two
Resistance, methods described also include：Obtain the resistance value of the sensor Q2；Selection is immediate with the resistance value of the sensor Q2
Resistance is as the load resistance R to be connected with the sensor Q2L。
For sensor cluster 31, as sensor Q2 variable resistors RS currency and load resistance RLResistance get over
Close, the precision that it is measured is higher.In the present embodiment, in order to ensure the measurement accuracy of gas concentration measuring apparatus, institute
Load matched resistance collection can be included by stating sensor cluster 31.The load matched resistance collection can include the electricity of multiple different resistances
Resistance.When detection, the variable resistor R of the sensor Q2 can be obtainedSCurrent resistance, will be with the variable resistor RSWork as
The preceding immediate resistance of resistance is as load resistance RLConnected with the sensor Q2.
In one embodiment, when first electric signal or the second electrical signal simulation voltage signal, in order to control
The signal that device 33 can export to sensor cluster 31 is identified and handled, and methods described also includes, by first telecommunications
Number, the second electric signal be converted to the first data signal and the second data signal；Accordingly, it is described to be based on the sensor cluster 31
Response curve and receive first electric signal, the second electric signal determine gas concentration be based on the sensor cluster 31
Response curve and first data signal, the second data signal determine the gas concentration.
In one embodiment, in order to be further ensured that the measurement accuracy of gas concentration, the gas concentration measurement side
Method also includes：The gas concentration is exported by predetermined mode, the predetermined mode includes：Count the loading of predetermined number
Gas concentration in cycle；Gas concentration in the loading cycle of the predetermined number is weighted averaging, described in acquisition
The output valve of gas concentration.
In the present embodiment, by counting multiple gas concentrations in loading cycle, then by multiple loading cycles
Gas concentration be weighted averaging, obtain the output valve of the gas concentration, gas concentration can be reduced in loading cycle
Influence of the interior change to output result.So that single loading cycle is 1 minute as an example, it can count what is obtained in first 10 minutes respectively
10 output valves, averaging then is weighted to 10 output valves, obtains current output valve.
In one embodiment, the gas concentration measuring method also includes being fitted the sensor Q2 curves
Processing, the mode of the process of fitting treatment include it is following in any one：Nonlinear fitting processing, sectional linear fitting processing.
Specific processing mode and result are referred to Fig. 4 and Fig. 5, and the description of gas concentration measuring apparatus embodiment.
In the present embodiment, the measurement range of the sensor Q2 can be：From ppb magnitudes to 10ppm magnitudes.Such as figure
Shown in 4, when carrying out sectional linear fitting processing to the sensor Q2 curves, gas concentration in the sensor Q2 curves is drawn
It is divided into following sections：0-0.3mg/m3, 0.3-3mg/m3, 3-10mg/m3。
Referring to Fig. 8, in one embodiment, the sensor cluster 31 is provided with what is connected with the sensor Q2
Load resistance RL, first electric signal is the first analog voltage, and second electric signal is the second analog voltage；Methods described
Also include：
Step S20：Judge under first predeterminated voltage, whether first analog voltage is less than or equal to the first of 3/4
Predeterminated voltage, under second predeterminated voltage, whether second analog voltage is more than or equal to 1/10 the second predeterminated voltage；
Step S22：If the determination result is YES, then the response curve based on sensor Q2 in the sensor cluster 31 and connect
First electric signal, the second electric signal received determine gas concentration；
Further, the sensor cluster 31 includes：The resistance of the different resistances of sensor Q2 and at least two, the biography
Sensor Q2 and one of resistant series, methods described also include：
Step S22：If the judged result is no, switch the resistance currently connected with the sensor Q2, repeat to add
The step of carrying voltage and determining gas concentration.
In the present embodiment, the first predetermined voltage is high voltage (5-7V), and the second predetermined voltage is low-voltage (2.5-
5V).When under the first predetermined voltage condition, load resistance RLVoltage be higher than 3/4 the first predetermined voltage, illustrate in the voltage
And under VOC concentration conditions, sensor Q2 variable resistors RS(inductive reactance) value is much smaller than its load resistance RLValue, causes sensor
Q2 and load resistance RLSeries circuit in load resistance RLPartial pressure is excessive, load resistance RLThe voltage signal at both ends will approach full
And state, so that sensor Q2 measurement sensitivity reduces, it is therefore desirable to switch to the less load resistance R of resistanceL.
Under second predetermined voltage condition, if load resistance RLVoltage signal be less than 1/10 the second predetermined voltage, then illustrate this
Load resistance R under partLResistance be much smaller than sensor Q2 variable resistor RS(inductive reactance) value, load resistance RLThe electricity at both ends
The measurement error that pressure signal close to 0, will cause condition lower sensor Q2 can be bigger, it is therefore desirable to it is larger to switch to resistance
Load resistance RL。
In one embodiment, the sensor cluster includes the sensor and the load with the sensor series
Resistance, first electric signal represent the first partial pressure of the load resistance, and second electric signal represents the load resistance
The second partial pressure, first partial pressure or the second partial pressure are directly proportional to the gas concentration.
In the present embodiment, as shown in figure 5, after the response curve to sensor Q2 carries out piece-wise linearization processing,
Gas concentration and load resistance R in every sectionLPartial pressure it is linear：C=(V-V0) * K, wherein, C represents gas concentration, V
Sensor output primary signal is represented, V0 represents sensor zero point, and K represents sensor response slope.For example, the response of sensor
When curve is divided into three sections according to the difference of gas concentration, its response slope has three different numerical value, is respectively：0.0114、
0.0676、0.2038。
Under same concentrations, different heating voltages is loaded to sensor cluster 31, such as (5V 3.3V) sensor Q2 corresponding
The voltage signal of output is different, but response curve is similar, can obtain following corresponding relation：
Formula (1)：C=(V5V-V05V)*K5V
Formula (2)：C=(V3.3V-V03.3V)*K3.3V
Wherein, V5VAnd V3.3VTo load partial pressure, i.e. the first partial pressure and the second partial pressure, it can be with actually measured, K5VAnd K3.3V
It can be determined by sensor Q2 response curve.
Under different heating voltage, there is predetermined corresponding relation between the zero point of sensor.Specifically, relation is as follows：
Formula (3)：
Wherein, m=2, n=2, then formula (3) be specifically：
Wherein, coefficient a, b, c in formula (3) are constant, can be closed by testing the zero-point voltage under different heating voltage
System obtains.
Based on formula (1), formula (2), formula (3), three unknown numbers obtained in equation can be solved equation：Current gas
Bulk concentration C, 5V the sensor zero point V0 that has drifted about under 3.3V5VAnd V03.3V。
For sensor, although similar in different heating voltage lower sensor response curves, sensor
Response curve can be variant.Specifically, Main Differences point is sensor origin difference.Wherein, the friendship of response curve and transverse axis
Meeting point is referred to as ' sensor origin '.The problem of traditional sensors, is ' sensor origin ' by temperature, humidity, concentration, time
Drift is produced Deng influenceing, is commonly called as ' sensor drift ' or null offset.Studies have found that：Sensor adds in two differences
There is predetermined corresponding relation in the origin output valve under thermal voltage, the null offset of sensor similar can regard equal proportion as
Drift.Therefore, based on the response curve under the different heating voltage disclosed in above-mentioned formula, by under two kinds of different heating voltages
Corresponding relation between zero point can eliminate the influence of null offset, so as to construct between new output and VOC gas concentration
Response relation, overcome Zero drift in main amplifier.During concrete operation, an actual zero point can be redefined out, the actual zero point can
Will not change substantially during sensor use.That is in sensor after long-time use, it is replaced in pure
When in net air, its output signal is identical or approximately the same with the zero signal initially demarcated all the time.Specifically, please refer to
Fig. 6, illustrated so that heating voltage is 5V and 3.3V as an example.
As shown in fig. 6, for one embodiment of the application provide by obtained under 5v and 3.3v heating voltages two
The new relation curve map for the sensor that response curve constructs.Wherein, abscissa is sensor raw signals；Ordinate is VOC
Concentration, unit are microgram/cubic meter (ug/m3)。
In theory, origin output valve origin output valve of the sensor under 3.3V substituted under two different heating voltages
Between predetermined corresponding relation i.e. obtain origin output valve of the sensor under 5V.Based on output valve under different heating voltage it
Between corresponding relation, new output (sensor raw signals) and VOC can be constructed with computing by 5v and 3.3v response curve
Response relation between gas concentration.As shown in fig. 6, even if 5v or 3.3v response curve goes out without sensor origin
In the case of now drifting about, neotectonics (response curve) can pass through sensor origin, that is to say, that for calculating gas output concentration
Benchmark be that the zero point of sensor will not drift about, you can to solve Zero drift in main amplifier.
Utility model people also verified to gas concentration measuring apparatus and method provided herein, the result
Show：Can also overcome when carrying out gas concentration measurement based on gas concentration measuring apparatus provided herein ambient temperature and
The influence of humidity.
As shown in figure 9, under 700ppbVOC concentration, using gas concentration measuring apparatus provided herein and correspondingly
Method measure.In figure, abscissa represents that testing time (Time) unit is minute (sec)；Ordinate represents VOC mixing
(mix) concentration of gas, unit ppb.Under the conditions of constant temperature and humidity, the gas concentration profile obtained over time is
Curve A.Then, temperature and humidity is adjusted, such as temperature can be to change between 25 degrees Celsius to 40 degrees Celsius for it, humidity can be with
Change 45% between 90%RH.Under conditions of alternating temperature is got wet, the gas that obtains over time, which majors in curve, is
Curve B.Correlation curve A and curve B, it is seen that the gas concentration of gas concentration measuring apparatus output is not with temperature and humidity
Change the change by a relatively large margin of jumping characteristic occurs, still maintain and basically identical output under the conditions of constant temperature and humidity.
As shown in Figure 10, under 950ppbVOC concentration, using gas concentration measuring apparatus provided herein and correspondingly
Method measure.In figure, abscissa represents that testing time (Time) unit is minute (sec)；Ordinate represents VOC mixing
(mix) concentration of gas, unit ppb.Under the conditions of constant temperature and humidity, the gas concentration profile obtained over time is
Curve C.Then, temperature and humidity is adjusted, such as temperature can be to change between 25 degrees Celsius to 40 degrees Celsius for it, humidity can be with
Change 45% between 90%RH.Under conditions of alternating temperature is got wet, the gas that obtains over time, which majors in curve, is
Curve D.Correlation curve C and curve D, it is seen that the gas concentration of gas concentration measuring apparatus output is not still with temperature and wet
The change by a relatively large margin of jumping characteristic, maintenance and output basically identical under the conditions of constant temperature and humidity occur for the change of degree, compare VOC
Concentration is more stable and reliable in 700ppb, is hardly influenceed by temperature and humidity.
As shown in figure 11, for using gas concentration measuring apparatus described herein and existing PID (Photo
Ionization Detectors) indoor test comparison diagram.Wherein, PID is generally acknowledged in moment sensor Q2 with preferable
Accuracy and sensitivity measurement apparatus, comparatively its cost is higher and the life-span is shorter.
In figure, abscissa represents that testing time (Time) unit is minute (sec)；Ordinate represents VOC mixing (mix)
The concentration of gas, unit ppb.Wherein, curve E is PID test curve, and curve F is that the gas concentration that the application provides is surveyed
Measure the test curve of device.As can be seen from Figure 10 when tested between point before 2000sec (minute), interior be in sealed shape
State, the measuring accuracy of gas concentration measuring apparatus provided herein and the PID are basically identical.After 2000sec, windowing
During ventilation, room air can be influenceed by ambient temperature and humidity.And after divulging information, indoor VOC should have bust in theory.
The influence of ambient temperature and humidity can be overcome using gas concentration measuring apparatus described herein, and it is defeated rapidly and sensitively
Go out the result consistent with current VOC.And PID can not react in time after windowing is divulged information, remain within and open
Consistent state before window ventilation.It can be seen that the accuracy of detection of gas concentration measuring apparatus provided herein, response speed, spirit
Comparatively sensitivity is better than PID.
In this application, controller 33 can be implemented in any suitable manner.Specifically, for example, controller 33 can be with
Take such as microprocessor or processor and storage can be by the microprocessor or the computer-readable program generation of computing device
Computer-readable medium, gate, switch, the application specific integrated circuit (Application of code (such as software or firmware)
Specific Integrated Circuit, ASIC), (the Programmable Logic of programmable logic controller (PLC) 33
Controller, PLC) and embedded micro-control unit (Microcontroller Unit, MCU) form, the example of above-mentioned module
Son includes but is not limited to following micro-control unit：ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20 and
Silicone Labs C8051F320.Those skilled in the art are it is to be understood that except with pure computer readable program code side
Formula realized beyond the function of the controller 33, completely can be by the way that method and step is carried out into programming in logic come control unit
It is identical to realize in the form of gate, switch, application specific integrated circuit, programmable logic controller (PLC) 33 and embedded micro-control unit etc.
Function.
Above-mentioned embodiment illustrates or module, it can specifically be realized by computer chip or entity, or by with certain
The product of kind of function is realized.The function of each module can be realized in same or multiple hardware when implementing the application.
It is of course also possible to the module for realizing certain function is combined into realization by multiple submodule or subelement.
Above-mentioned each embodiment in this specification is described by the way of progressive, identical between each embodiment
Similar portion is cross-referenced, and what each embodiment stressed is and other embodiment difference.
Several embodiments of the present utility model are the foregoing is only, although the embodiment disclosed by the utility model is such as
On, but the content is only to facilitate the embodiment for understanding the utility model and using, it is new to be not intended to limit this practicality
Type.Any the utility model person of ordinary skill in the field, the spirit and scope disclosed by the utility model are not being departed from
On the premise of, any modification and change, but patent of the present utility model can be made in the formal and details of embodiment
Protection domain, it must be still defined by the scope that appended claims are defined.
Claims (13)
- A kind of 1. gas concentration measuring apparatus, it is characterised in that including：Sensor cluster, it includes the sensor and load resistance that can be connected in a series arrangement, for connecting the input of voltage source Terminal, for exporting the lead-out terminal of the sensor cluster electric signal；By loading at least the first predetermined voltage and the second predetermined voltage to the sensor cluster input terminal respectively, institute is received The first electric signal corresponding to lead-out terminal and the second electric signal are stated, and gas is determined based on first electric signal and the second electric signal The controller of bulk concentration.
- 2. gas concentration measuring apparatus as claimed in claim 1, it is characterised in that the sensor cluster also includes：Comprising The resistance collection of the different first resistor of at least two resistances and second resistance, the load resistance are the resistance lumped resistance value With the immediate resistance of the current resistance of the sensor.
- 3. gas concentration measuring apparatus as claimed in claim 1, it is characterised in that the sensor is mutually gone here and there with load resistance Connection, the lead-out terminal are used for analog voltage signal or the simulation at the load resistance both ends for obtaining the sensor both ends Voltage signal.
- 4. gas concentration measuring apparatus as claimed in claim 3, it is characterised in that first electric signal or the second electric signal For the analog voltage signal；The gas concentration measuring apparatus also includes the change-over circuit that the analog voltage signal is converted to data signal, described Change-over circuit is electrically connected with the lead-out terminal of the sensor cluster and the controller respectively.
- 5. gas concentration measuring apparatus as claimed in claim 1, it is characterised in that also include：First voltage source and the second electricity Potential source, and be electrically connected with the controller and the first voltage source or the second voltage source and the input terminal can be switched The switch unit of connection.
- 6. gas concentration measuring apparatus as claimed in claim 1, it is characterised in that also include：It can connect with the input terminal Connect and the voltage source of the first predetermined voltage and the second predetermined voltage can be provided to the sensor cluster.
- 7. gas concentration measuring apparatus as claimed in claim 1, it is characterised in that the sensor cluster is provided with heating Device, it is the heating being carried on the heater to be carried in the first predetermined voltage of the sensor cluster or the second predetermined voltage Voltage, the sensor cluster are additionally provided with the loop voltage for power supply, and first predetermined voltage is more than or equal to described return Road voltage, second predetermined voltage are less than or equal to the loop voltage, and it is predetermined that first predetermined voltage is more than described second Voltage.
- 8. gas concentration measuring apparatus as claimed in claim 7, it is characterised in that first predetermined voltage is the loop 1.4 times to 1 times of voltage；Second predetermined voltage is 0.5 times to 1 times of the loop voltage.
- 9. gas concentration measuring apparatus as claimed in claim 8, it is characterised in that the loop voltage be 5 volts, described first Predetermined voltage between 5 volts to 7 volts, second predetermined voltage between 2.5 volts to 5 volts, wherein, first predetermined voltage More than second predetermined voltage.
- 10. gas concentration measuring apparatus as claimed in claim 1, it is characterised in that during the loading of first predetermined voltage Between scope be 10 seconds to 60 seconds；The load time scope of second predetermined voltage is 10 seconds to 60 seconds.
- 11. gas concentration measuring apparatus as claimed in claim 1, it is characterised in that also include electrically connecting with the controller The display connect, for showing the gas concentration.
- 12. gas concentration measuring apparatus as claimed in claim 1, it is characterised in that also include electrically connecting with the controller The communication module connect.
- 13. a kind of air purifier, it is characterised in that the air purifier sets any just like claim 1 to 12 described Gas concentration measuring apparatus.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107449809A (en) * | 2017-09-28 | 2017-12-08 | 艾欧史密斯(中国)热水器有限公司 | gas concentration measuring method, device and air purifier |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107449809A (en) * | 2017-09-28 | 2017-12-08 | 艾欧史密斯(中国)热水器有限公司 | gas concentration measuring method, device and air purifier |
| CN107449809B (en) * | 2017-09-28 | 2019-03-12 | 艾欧史密斯(中国)热水器有限公司 | Gas concentration measuring method, device and air purifier |
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Assignee: A. O. SMITH (CHINA) ENVIRONMENTAL PRODUCTS Co.,Ltd. Assignor: AOSMITH (China) water heater Co.,Ltd. Contract record no.: X2022990000446 Denomination of utility model: Gas concentration measuring device and air purifier Granted publication date: 20180403 License type: Common License Record date: 20220729 |
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