CN103149441A - Portable impedance spectrum analyzer applied to electrochemical measurement and impedance spectrum analyzing method - Google Patents

Abstract

The invention discloses a portable impedance spectrum analyzer applied to electrochemical measurement. The portable impedance spectrum analyzer mainly comprises an impedance analyzing chip, a feedback resistance network, a measurement switching circuit and a main controller, wherein the impedance analyzing chip is used for measuring a gain factor and impedance data of an electrochemical system to be measured and transmitting the measuring result to the main controller; the feedback resistance network is used for providing different shifts of feedback resistances and corresponding calibration resistances to the impedance analyzing chip; the measurement switching circuit is used for switching between the different shifts of feedback resistances and the calibration resistances and switching between the calibration resistances and the electrochemical system to be measured; the main controller is used for controlling the on/off of a first switching switch and a second switching switch in the measurement switching circuit; and the impedance spectrum of the electrochemical system to be measured is obtained through calculation according to the data measured by the impedance analyzing chip. The shifts of the feedback resistances are changed through the feedback resistance network and a wider impedance value measuring range is realized.

Description

Portable Impedance Spectrum Analyzer Applied to Electrochemical Measurement and Impedance Spectrum Analysis Method

technical field

The invention belongs to the field of electrochemical impedance spectrum analysis, and in particular relates to a portable impedance spectrum analyzer and analysis method applied to electrochemical measurement.

Background technique

In the research process of electrochemical performance, the method of measuring electrochemical impedance spectroscopy is often used.

Electrochemical Impedance Spectroscopy (EIS for short) is an electrochemical measurement method that uses a small-amplitude sine wave valence (or current) as a disturbance signal. Since the electrochemical system is perturbed by a small-amplitude electrical signal, on the one hand, it can avoid a large impact on the system, and on the other hand, the relationship between the disturbance and the response of the system is approximately linear, which makes the mathematical processing of the measurement results made easy. At the same time, the electrochemical impedance spectroscopy method is a measurement method in the frequency domain. It uses the measured impedance spectrum with a wide frequency range to study the electrode system, so it can obtain more kinetic information than other conventional electrochemical methods. And the information of the electrode interface structure.

Apply a small-amplitude AC potential wave with different frequencies to the electrochemical system, and measure the ratio of the AC potential to the current signal (this ratio is the impedance of the system) as the frequency of the sine wave ω changes, or the phase angle of the impedance Φ varies with ω The change. At this time, the frequency response function of the electrode system is the electrochemical impedance. A set of such FRF values measured at a range of different frequencies is the electrochemical impedance spectrum of the electrode system.

At present, the products on the market that can perform electrochemical impedance spectroscopy measurement include electrochemical workstations, frequency response analyzers, precision LCR instruments and other equipment. These devices can perform multi-frequency point impedance measurement, with high precision and perfect software design, but they are expensive, bulky, not easy to carry, complex in design, cumbersome to use, and difficult for non-professionals to use. Another type of measuring equipment is small in size but poor in function. Generally, it can only measure impedance information at a few or one frequency point, or the range of impedance values that can be measured is small, the analysis ability is weak, and human-computer interaction is inconvenient.

Contents of the invention

The purpose of the present invention is to provide a portable impedance spectroscopy analyzer and analysis method applied to electrochemical measurement, which provides a high-performance solution for field-level electrochemical measurement, and its operation is simple, fast, reliable, and low-cost. Cost measurement devices and measurement methods.

The invention provides a portable impedance spectrum analyzer applied to electrochemical measurement, which comprises:

Impedance analysis chip, which is used to measure the impedance data of the electrochemical system, and transmit the measured data to the main controller;

A feedback resistor network, which is used to provide feedback resistors of different gears and corresponding calibration resistors to the impedance analysis chip;

A measurement switch circuit, which includes a first switch and a second switch, the first switch is used to switch between feedback resistors of different gears in the feedback resistor network, and the second switch is used for feedback in the current gear Switch between the calibration resistance corresponding to the resistance and the electrochemical system to be tested;

a main controller, which is used to control the on-off of the first switching switch and the second switching switch in the measurement switching circuit; it also calculates and obtains the electrochemical system to be measured according to the data measured by the impedance analysis chip. Impedance spectrum;

Wherein, during the system calibration period, the impedance analysis chip is connected with the feedback resistance and the calibration resistance under different gears respectively, and is used to measure the gain coefficient under different gears; The feedback resistor under the position is connected with the electrochemical system to be tested, and is used to measure the impedance data of the electrochemical system to be tested under different gears. Gain coefficient under the position to obtain the impedance value of the electrochemical system to be tested.

The present invention also provides a method for impedance spectrum analysis of the electrochemical system to be measured, which includes:

Step 1: Connect the feedback resistors and calibration resistors of different gears to the impedance analysis chip in sequence;

Step 2: The impedance analysis chip measures the corresponding calibration resistance under the feedback resistance of different gears in sequence to obtain the calibration data;

Step 3: Calculate and obtain the gain coefficients under the feedback resistors of different gears according to the calibration data;

Step 4: Connect the feedback resistors of different gears and the electrochemical system to be tested to the impedance analysis chip in sequence;

Step 5: The impedance analysis chip measures the electrochemical system to be tested under the feedback resistance of different gears in sequence to obtain the measurement data;

Step 6: According to the measurement data and the gain coefficient under the same gear feedback resistance calculated in step 3, calculate the impedance data of the electrochemical system to be tested under different gear feedback resistances;

Step 7: Comparing the calculated impedance data of the electrochemical system to be tested with the corresponding feedback resistance to finally obtain the impedance value of the electrochemical system to be tested.

The above-mentioned solution provided by the present invention has the following advantages: the feedback resistance gear is changed through the resistance feedback network, and a large impedance value measurement range is realized; the main control is by setting parameters such as the initial frequency, frequency increment and increment number of the impedance analysis chip The portable impedance spectrum analyzer is small in size and suitable for the field of disease prevention and control at the field level and has real-time detection requirements. The electrochemical measurement method has great application potential in the fields of analytical chemistry, materials chemistry, biology, medicine, clinical testing, industrial analysis, environmental monitoring and agricultural analysis.

Description of drawings

Fig. 1 is the structural block diagram of the portable impedance spectroscopy analyzer that is applied to electrochemical measurement among the present invention;

Fig. 2 is a schematic diagram of the principle of impedance spectroscopy measurement in the present invention;

Fig. 3 is a schematic diagram of the principle of the feedback resistor network in the present invention;

Fig. 4 is a flow chart of the impedance spectrum analysis method in the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

Fig. 1 shows a schematic structural diagram of a portable impedance spectroscopy analyzer applied to electrochemical measurement in the present invention. As shown in Figure 1, the present invention discloses a portable impedance spectrum analyzer applied to electrochemical measurement, which includes:

Main controller 1, which makes the various components of the system work in a coordinated manner;

An output device 2, the input end of which is connected to the first output end of the main controller 1, which is used to display the measurement and processing results of the system, and the displayed content is controlled by the output control signal of the main controller;

The input device 3, its output end is connected with the first input end of the main controller 1, the user inputs the system parameters to the main controller 1 through the input device 3 when performing impedance measurement of the electrochemical system to be tested, and the system parameters include the The spectral range and spectral resolution of the impedance spectrum when the electrochemical system performs impedance measurement, as well as other related parameters, such as the starting frequency, the number of scanning points and the frequency increment, etc.; wherein, the number of scanning points represents the different Frequency times.

The host interface 4, its input end is connected with the second output end of the main controller 1, and it uploads the measurement data saved by the system to the upper computer, computer or smart device through the host interface;

Impedance analysis chip 5, its first input end is connected with the second input end of main controller 1, is used for receiving from main controller 1 the system parameter when measuring the electrochemical system to be measured, and utilizes the received said The system parameters are used to set the output frequency of the excitation signal when the electrochemical system to be tested is measured; and the frequency is continuously changed through the initial frequency and frequency increment in the system parameters to achieve the impedance of the electrochemical system to be measured under the frequency spectrum Measurement; its second input end is connected with the measurement switching circuit 9; and the feedback resistance under the different gears in the feedback resistance network 8 is connected through the switching switch in the measurement switching circuit 9, and the electrochemical system to be measured is connected simultaneously or with the measured electrochemical system. The feedback resistance under the connected current gear corresponds to the set calibration resistance, so as to measure the impedance measurement data of the electrochemical system to be tested and the calibration resistance under the same feedback resistance, and transmit the measurement data to the main controller 1;

A power supply 6, the first output of which is connected to the third input of the main controller 1, which is used to provide power to the main controller;

The switch drive circuit 7, its first input terminal is connected to the third output terminal of the main controller 1, and the second input terminal is connected to the second output terminal of the power supply 6, and the main controller 1 realizes the control switch by using the high and low levels of the pins The on-off of the drive circuit 7, the power supply 6 supplies power to the switch drive circuit 7; the switch drive circuit 7 provides the drive voltage for the measurement switching circuit 9, so as to switch the on-off of each group of switches in the measurement switching circuit 9 according to the control of the main controller 1. broken;

Feedback resistor network 8, which is designed based on the measurement principle of the automatic balance bridge method, includes feedback resistors of various gears, and each feedback resistor of each gear is correspondingly provided with a calibration resistor with equal impedance value, and its input The end is connected with the first output end of the measurement switching circuit 9;

Measuring switching circuit 9, its first output end is connected with the input end of feedback resistance network 8, and the second output end is connected with the second input end of impedance analysis chip 5; It comprises the first switching switch and the second switching switch, the first The switching switch includes multiple groups, each group of the first switching switch is connected to the feedback resistors of different gears in the feedback resistor network 8, and the second switching switch is used to switch between the electrochemical system to be measured or the calibration resistor; the measurement switching Under the control of the switch drive circuit 7, the circuit 9 selects the feedback resistors connected to the different gears, and at the same time switches between the electrochemical system to be tested or the calibration resistors corresponding to the feedback resistors in the gears, so that they Access the impedance analysis chip 5; the switching switch in the measurement switching circuit 9 is a conversion switch, which can be a relay switch or an analog switch;

The reference voltage source 10 of the electrochemical system to be measured is connected with the second output end of the power supply 6 at its input end, and connected with the third input end of the impedance analysis chip 5 at its output end. The power supply 6 supplies power for the reference voltage source 10, and the reference voltage The source 10 provides a reference voltage for the impedance analysis chip 5 .

Among them, the main controller 1, the output device 2, the input device 3, the host interface 4, the impedance analysis chip 5, the reference voltage source 10, the power supply 6 and the switch driving circuit 7 constitute the main control unit.

The switching switch in the measurement switching circuit 9 of the present invention is realized by a relay, and may also be realized by an analog switch with a small conduction resistance. In a preferred embodiment of the present invention, relays are selected for implementation, and each relay corresponds to a feedback resistance gear. Table 1 shows the feedback resistors under 6 different gears and the corresponding calibration resistors. At this time, the measurement switching circuit 9 needs 7 relays, of which 6 relays are used to switch the feedback resistors of 6 gears. A relay is used to switch between the electrochemical system to be tested and the calibration resistor, as shown in FIG. 2 and FIG. 3 .

Table 1 Feedback resistor network gear setting

R _FB scope Corresponding to Vi input voltage 1KΩ ZMIN＝1KΩ 2Vp-p ZMAX＝3.3KΩ 0.67Vp-p 3.3KΩ ZMIN＝3.3KΩ 2Vp-p ZMAX＝10KΩ 0.67Vp-p 10KΩ ZMIN＝10KΩ 2Vp-p ZMAX＝33KΩ 0.67Vp-p 33KΩ ZMIN＝33KΩ 2Vp-p ZMAX＝100KΩ 0.67Vp-p 100KΩ ZMIN＝100KΩ 2Vp-p ZMAX＝330KΩ 0.67Vp-p 330KΩ ZMIN＝330KΩ 2Vp-p ZMAX＝1MΩ 0.67Vp-p

Fig. 2 shows the schematic diagram of the circuit between the electrochemical system to be tested, the impedance analysis chip 5, the measurement switching circuit 9 and the feedback resistor network 8, wherein the measurement switching circuit 9 includes a relay J7 and relays J1-J6, and the relay J7 is used for Switch the electrochemical system to be tested and the calibration resistor, and the relays J1-J6 are used to switch the feedback resistors under 6 gears. Figure 2 only shows the feedback resistor of one gear and one of the relays J1-J6. Figure 3 shows the specific composition of the 6 gear feedback resistors and relays J1-J6. As shown in FIG. 2 , the external feedback resistor and the calibration resistor are provided by the feedback resistor network 8 , which are the feedback resistor and the corresponding calibration resistor in one gear. For example, in the measurement process, when first selecting 1KΩ impedance calibration, the relay J1 must be closed and the relays J2~J6 must be disconnected, and at the same time, the two short-circuit contacts Vin and Vout of the relay J7 are connected to the two terminals R STD_ a and R _{STD_a} of the calibration resistor. When R _{STD_} b is connected, it means that the impedance analysis chip 5 is connected with the 1KΩ feedback resistor and the corresponding calibration resistor to measure the gain coefficient of the impedance when the calibration resistor is connected, and the two short-circuit contacts Vin and Vout of the relay J7 are connected to the When the two terminals Z _{OUT_} a and Z _{OUT_} b of the measured electrochemical system are connected, it is used to measure the impedance of the measured electrochemical system.

The 7 relays are provided with current by the switch drive circuit 7, the switch drive circuit 7 includes 7 triodes, the base of each triode is connected with 7 GPIO ports of the main controller 1, and each triode's The collectors are respectively connected to the 7 relays. Therefore, the 7 GPIO ports of the main controller individually control the on-off of one relay.

During the system calibration period, the main controller 1 first selects the calibration resistor in the feedback resistor network as the DUT by controlling the on-off of the relay J7, and uses the known calibration resistor connected between the Vin and Vout terminals to calculate the different gears under the gain factor. During system calibration, only one of the 6 relays in Figure 3 is connected at a time, and the two short-circuit contacts Vin and Vout of the relay J7 are connected to R _{STD_a} and R _{STD_b} respectively, and then the impedance analysis chip 5 is started to scan the frequency and record For the impedance value at the current frequency, the frequency range can be 15KHz to 100KHz, and the frequency increment can be 1KHz. In order to improve the accuracy, repeat the test for each frequency, for example, 20 times, and average the data to get 6 different feedback resistor gain coefficients at 85 frequency points switched on.

After the system calibration is finished, switch the calibration resistance to the electrochemical system to be tested by controlling the relay J7 on and off, that is, the two short-circuit contacts Vin and Vout of the relay J7 are connected to ZDUT_a and ZDUT_b respectively, and measured by the above method, through the data After processing, the impedance spectrum distribution of the electrochemical system to be tested can be obtained. That is, the impedance analysis chip 5 measures the measured value when the feedback resistance of different gears is connected to the electrochemical system to be tested, and according to the measured value and the gain coefficients obtained above in different gears, the electrochemical resistance to be tested in different gears is obtained. The impedance of the system is to obtain 6 impedance values, and compare the 6 impedance values with the corresponding feedback resistance values, and the impedance value with the highest degree of proximity is used as the impedance value of the electrochemical system to be tested.

Specifically, since the input range fed back to the receiving end of the impedance analysis chip 5 is 2Vp-p. The voltage Vin at the input can be expressed as:

$\mathrm{<span\; class="notranslate">\; Vin</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Vout</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; Facebook</span>}}}{{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; DUT</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; G</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Wherein, Vout is the output terminal VOUT voltage of the excitation sinusoidal signal of the impedance analysis chip 5, R _FB is the feedback resistor, Z _DUT is the impedance of the electrochemical system to be measured, and G is the gain of the internal amplification circuit of the impedance analysis chip 5. The main controller 1 sets the amplitude Vout of the output excitation signal and the gain G of the internal amplifier circuit to the impedance analysis chip 5 through the I ² C bus. When Vout and G are constant, an appropriate R _FB is adopted according to the size of _zDUT , so that the received voltage signal Vin of the impedance analysis chip 5 is controlled within the input range of the receiving end VIN pin of the impedance analysis chip 5 . However, on the other hand, for a certain impedance to be measured _zDUT (Vout, G is constant), if R _FB is selected too small, the amplification factor in the current-voltage conversion circuit will not be appropriate, which will make the input signal Vin The amplitude is small. Failure to amplify the useful signal to an appropriate multiple will reduce the signal-to-noise ratio of the useful signal, thereby affecting the accuracy of the measurement. Therefore, an appropriate feedback resistor R _FB should be selected according to the impedance to be measured, so that the Vin input voltage can be controlled within a reasonable range. The schemes that can be selected for the gear setting of the feedback resistor network are shown in Table 1.

As shown in Table 1, there are six gears in total, and the corresponding resistance values of the feedback resistor R _FB are 1KΩ, 3.3KΩ, 10KΩ, 33KΩ, 100KΩ and 330KΩ. For an unknown electrochemical system to be tested, by selecting an appropriate R _FB , the amplitude of the input signal Vin can be controlled within the range of 2Vp-p. This not only ensures that Vin will not exceed the input range of the VIN pin, but also ensures that the signal-to-noise ratio of the response signal will not decrease because Vin is too small.

The reference voltage source 10 of the present invention is used to convert the external power supply 9 from 5V to 3.3V, so as to maximize the measurement accuracy of the impedance analysis chip 5 .

The main controller 1 can choose the model STM32F103ZET6; the impedance analysis chip 5 can choose the model AD5933; the reference voltage source 10 can choose the model REF3033; the relay type in the measurement switching circuit 9 can choose the model TQ2-5V.

The present invention also discloses a method for performing impedance spectrum analysis of the electrochemical system to be measured by using the above-mentioned portable impedance spectrum analyzer applied to electrochemical measurement, which includes the following steps:

Step 1: Through the input device 3, input the system parameters of the impedance measurement of the electrochemical system to be measured to the main controller 1, and the system parameters include: the starting frequency, the number of scanning points and Frequency increment, etc.;

Step 2: The main controller 1 transmits the system parameters to the impedance analysis chip 5 through the bus, and the impedance analysis chip 5 uses the received system parameters to control the output frequency, amplitude, etc. of its output excitation signal. Wherein, when measuring for the first time, the output frequency of its excitation signal is set as the starting frequency specified in the system parameter, and after each measurement is completed, the output frequency of the excitation signal is increased according to the frequency increment in the system parameter, Then carry out the measurement at the next frequency, and finally realize the impedance measurement of the electrochemical system to be tested under the frequency spectrum;

Step 3: Perform system calibration. The main controller 1 introduces feedback resistors of different gears in the feedback resistor network 8 successively by controlling the switch drive circuit 7, and connects the calibration resistor corresponding to the feedback resistor of the gear with the impedance analysis chip 5, and the impedance The analysis chip 5 measures and obtains the measurement data under this gear. During the measurement process, the impedance analysis chip 5 transmitter stage outputs an excitation signal with a frequency set in step 2. After the excitation signal passes through the calibration resistance, then passes through the feedback resistance, and finally re-enters the receiving end of the impedance analysis chip 5, and The impedance analysis chip 5 performs discrete Fourier transform on the input signal to obtain the real part and the imaginary part, which are used as the measurement data of the calibration resistance. Since the calculation of the gain coefficient is related to the size of the feedback resistor, the gain coefficient of different feedback resistor gears can be measured by connecting the feedback resistors in different gears and the corresponding calibration resistors;

Step 4: The impedance analysis chip 5 transmits the measurement data obtained each time to the main controller 1 through the bus, and then the main controller 1 calculates the gain coefficient of the feedback resistance at different gears, and the calculation formula is as follows:

Step 5: the main controller 1 switches the second switch in the measurement switch circuit 9 by controlling the switch drive circuit 7, so that the impedance analysis chip 5 is disconnected from the calibration resistor and connected to the electrochemical system to be measured; The impedance analysis chip 5 measures the measurement data of the electrochemical system to be tested under different levels of feedback resistance, and transmits the measurement data obtained each time to the main controller 1 through the bus. Its measurement process is the same as that of measuring calibration resistance.

Step 6: The main controller 1 obtains the impedance value according to the measurement data of the electrochemical system to be tested received from the impedance analysis chip 5 and the gain coefficient calculated in step 4; the specific calculation is as follows:

Wherein, the imaginary part and the real part are the measurement data of the electrochemical system to be tested obtained in step 5;

Step 7: The main controller 1 compares the proximity of the impedance of the electrochemical system to be tested measured at each gear position with the feedback resistance at the corresponding gear position, and uses the impedance with the highest proximity as the electrochemical system to be tested the impedance value. Because the closer the size of the feedback resistor is to the impedance of the electrochemical system to be tested, the more accurate it is, by successively measuring the gain coefficients corresponding to different feedback impedances with feedback resistors of different gears, and calculating the electrochemical system to be tested according to the gain coefficients under different feedback impedances. system impedance, and then compare the measured proximity between the electrochemical system to be measured and the corresponding feedback resistance, and select the feedback impedance with the highest proximity as the impedance value of the electrochemical system to be measured. For example, at a specific frequency, the actual impedance of the electrochemical system to be tested is 20kΩ, and the feedback resistors of the three gears of 1kΩ, 10kΩ and 100kΩ are used to measure and calculate, and finally get 3 impedance values, and these 3 Among the impedance values, the impedance value obtained under the feedback resistance gear of 10kΩ must be the closest to the actual impedance value of the electrochemical system to be measured, so its result should be used as the measurement result;

Step 8: According to the frequency increment in the system parameters, the impedance analysis chip 5 increases the scanning frequency, and repeats the above steps. The number of repetitions N is the number of scanning points to measure the impedance value of the electrochemical system to be tested at different frequencies, and then obtain the Measure the impedance spectrum distribution of the electrochemical system and complete the impedance spectrum analysis.

The present invention adopts the main controller 1, the output device 2 and the keyboard 3 to cooperate with the operation and display, set the initial frequency, the number of scanning points and the frequency increment, send various control commands by the main controller, and control the impedance analysis through the I2C signal Chip 5 to complete the corresponding operations. The main controller 1 uses the STM32 series chip with ARM core. The impedance analysis chip calculates the impedance spectrum of the electrochemical system to be tested through different calibration resistors and feedback resistors and uses the on-chip DSP. After being retrieved and analyzed, it is sent to the output device 2 for display, and finally the impedance spectrum measurement of the electrochemical system to be tested is completed. In addition, the host interface 4 can transmit the measured data to a PC for further research or storage of measured data.

The portable impedance spectrum analyzer applied to electrochemical measurement adopts a highly integrated impedance analysis chip and uses an impedance feedback network to meet the requirements of impedance measurement range and multi-frequency point impedance measurement. The application of the integrated impedance analysis chip and related circuits not only effectively controls the cost of the equipment, but also has a good performance in the accuracy of the test results. It can also use an external battery power supply to make the present invention small in size, easy to carry and other advantages. A new scheme is provided for impedance measurement applied to electrochemical elements.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. portable Impedance Analysis instrument that is applied to electrochemical measurement, it comprises:

The impedance analysis chip, it is used for measuring the impedance data of electro-chemical systems, and sends the data that record to master controller;

Feedback resistive network, it is used for providing to the impedance analysis chip feedback resistance and the corresponding calibrated resistance of different gears;

Measure commutation circuit, it comprises the first change-over switch and the second change-over switch, the first change-over switch is used for switching between the feedback resistance of the different gears of feedback resistive network, and the second change-over switch is used for switching between calibrated resistance corresponding to the feedback resistance of current gear and electro-chemical systems to be measured;

Master controller, it is used for controlling first of described measurement commutation circuit and switches the break-make of opening with the second change-over switch; Its data that also record according to described impedance analysis chip calculate the impedance spectrum of described electro-chemical systems to be measured;

Wherein, during system calibration, described impedance analysis chip respectively from different gears under feedback resistance be connected with calibrated resistance, be used for measuring the gain coefficient under different gears; In the systematic survey stage, described impedance analysis chip is connected with electro-chemical systems to be measured from feedback resistance under different gears, be used for measuring the impedance data of electro-chemical systems to be measured under different gears, master controller obtains the resistance value of electro-chemical systems to be measured according to the impedance data of electro-chemical systems to be measured under described different gears and the gain coefficient under different gear.

2. analyser as claimed in claim 1, is characterized in that, described analyser is used for measuring the resistance value of described electro-chemical systems to be measured under different frequency, obtains the impedance spectrum of described electro-chemical systems to be measured under frequency spectrum with analysis.

3. analyser as claimed in claim 2, it is characterized in that, described analyser also comprises input equipment, the systematic parameter when being used for input measurement and analyzing the impedance spectrum of described electro-chemical systems to be measured, and described systematic parameter comprises initial frequency, number of scan points and frequency increment.

4. analyser as claimed in claim 1, is characterized in that, described master controller is controlled the break-make of change-over switch in described measurement commutation circuit by current drives.

5. analyser as claimed in claim 1, it is characterized in that, described the first change-over switch and the second change-over switch are relay, and described the first change-over switch comprises many groups, and described many groups the first change-over switch is connected with calibrated resistance from the feedback resistance of a plurality of different gears respectively.

6. analyser as claimed in claim 1, is characterized in that, described gain coefficient calculates according to described impedance analysis chip feedback resistance value under data that access records during calibrated resistance and current gear.

7. analyser as claimed in claim 1, is characterized in that, the resistance value of described electro-chemical systems to be measured calculates according to the gain coefficient of described impedance analysis chip feedback resistance under data that access records during electro-chemical systems to be measured and current gear.

8. analyser as claimed in claim 1, is characterized in that, the feedback resistance of same gear is identical with the resistance value of calibrated resistance.

9. method of electro-chemical systems to be measured being carried out Impedance Analysis, it comprises:

Step 1: successively with feedback resistance and the calibrated resistance termination analysis chip of different gears;

Step 2: the impedance analysis chip under different gear feedback resistances, is measured corresponding calibrated resistance successively, obtains calibration data;

Step 3: calculate gain coefficient under different gear feedback resistances according to described calibration data;

Step 4: successively with feedback resistance and the electro-chemical systems termination analysis chip to be measured of different gears;

Step 5: the impedance analysis chip under the feedback resistance of different gears, is measured electro-chemical systems to be measured successively, obtains measurement data;

Step 6: according to the gain coefficient under the identical gear feedback resistance that calculates in described measurement data and step 3, calculate the impedance data of described electro-chemical systems to be measured under different gear feedback resistances;

Step 7: according to the electro-chemical systems impedance data to be measured that calculates and correspondingly feedback resistance compare, finally obtain the resistance value of electro-chemical systems to be measured.

10. method as claimed in claim 9, is characterized in that, described method also comprises:

Step 8: increase the frequency sweep frequency of described impedance analysis chip, repeating step 1-7, the resistance value of described electro-chemical systems to be measured under the acquisition different frequency is to obtain the Impedance Analysis result of electro-chemical systems to be measured under frequency spectrum.

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