CN202758002U - Resistivity testing device - Google Patents

Abstract

The utility model discloses a resistivity testing device, which comprises a bottom plate, a fixing frame fixed on the bottom plate for fixing a piece to be tested, a guide column fixed on the bottom plate, and a An adjusting pressure plate with a scale, a detection electrode arranged on the adjustment pressure plate for contacting the object to be tested, and a resistance detection device connected with the detection electrode. The resistivity testing device of the utility model can measure its resistance under the measurement length of the required piece to be tested, and can calculate the resistivity through the formula once, and can measure the resistance of the same piece under test under different measurement lengths, and calculate different values through the formula. Measure the resistivity under the length to ensure the accuracy of the test results. Overall, the resistivity testing device of the utility model has a simple structure and is convenient to use, and can accurately measure the resistivity of carbon fibers.

Description

A resistivity testing device

technical field

The utility model relates to the field of resistivity testing devices, in particular to a resistivity testing device for carbon fiber resistivity detection.

Background technique

Carbon fiber has the characteristics of high tensile strength and tensile modulus, low density, fatigue resistance, corrosion resistance, etc. Therefore, it is often used as a reinforcement to prepare various composite materials such as carbon/carbon composite materials, carbon fiber reinforced resin-based composite materials, Carbon fiber reinforced ceramic matrix composites, etc. The application of carbon fiber covers aerospace, sports and leisure, and various civil applications.

Carbon fiber has a certain degree of electrical conductivity. Although its electrical conductivity is not as good as that of traditional metal conductors, as a non-metallic conductor, carbon fiber has received extensive attention. The conductivity of carbon fiber has also become an indicator of carbon fiber performance. At present, the main test standard for the performance test of carbon fiber resistivity is the aerospace industry standard QJ 3074-98 carbon fiber and its composite material resistivity test method, although the principle and calculation formula of carbon fiber resistivity test are briefly introduced in this standard , but at present there is no special test device reported in the country, and the final test results of different testing institutions are also different.

The Chinese invention patent application with the application publication number CN102288825A discloses a method for measuring the resistance value of the aluminum layer on the surface of a carbon fiber composite material part, which includes the following steps: 1) Make a sample with a thickness of 2~4mm on the existing carbon fiber composite material, spray After the aluminum layer, the corresponding relationship curve between the thickness of the aluminum layer and the resistance value is obtained; 2) Use an ultrasonic thickness gauge to measure the thickness of the aluminum layer on the surface of the carbon fiber composite material to be tested; 3) Put the thickness value into the thickness of the aluminum layer and The corresponding resistance value can be obtained from the corresponding relationship curve of the resistance value. Although this technical solution can infer the resistance value of the aluminum layer by measuring the thickness of the material, this technical solution cannot be applied to the test for detecting the resistivity of carbon fibers.

The existing carbon fiber resistivity generally measures the resistance of carbon fiber through the head of the multimeter, and then measures the length with a ruler, and then calculates the resistivity through a formula. However, the multimeter and ruler are measured twice, and it is difficult to guarantee the accuracy of the measurement. , At the same time, the measurement process is cumbersome to measure the resistance of the same carbon fiber under different lengths.

Utility model content

The utility model provides a resistivity testing device, which can measure the resistance of the required measuring length of the piece to be measured, calculate the resistivity through a formula once, and measure the resistance of the same measuring piece at different measuring lengths , through the formula to calculate the resistivity under different measurement lengths, so as to ensure the accuracy of the test results.

A resistivity testing device, comprising a base plate, a fixing frame fixedly arranged on the base plate for fixing the object to be tested, a guide column fixed on the base plate, and an adjusting pressure plate with a scale arranged on the guide column , a detection electrode arranged on the adjustment platen for contacting the object under test, and a resistance detection device connected to the detection electrode.

The piece to be tested can be made of carbon fiber, etc. Fix the piece to be tested on the fixed frame, and then adjust the distance between the detection electrodes based on the scale on the adjustment pressure plate as required, and then move the adjustment pressure plate so that the detection electrodes on the adjustment pressure plate are in contact with each other. The resistance value of the test piece is measured by the resistance detection device, and finally the resistivity of the test piece is obtained through the formula.

The resistance detection device can adopt the existing technology, such as a multimeter, etc. The multimeter can generally select the detection mode according to the needs, and when detecting the resistance, it can generally provide a certain current by itself for detection. In order to further improve the accuracy of detection, preferably, the resistance detection device includes a voltmeter for detecting the voltage of the test piece under the measurement length and an ammeter for detecting the current of the test piece under the measurement length, and the voltmeter Both the ammeter and the ammeter are connected to the detection electrodes, and current terminals are installed at both ends of the fixing frame. The current terminal is connected to a power supply, and the current terminal is used to provide current for the piece under test under the measurement length, and the voltage value and current value are obtained through the voltmeter and ammeter, and the resistance of the piece under test under the measurement length is calculated through the voltage value and current value, which is beneficial Improve the accuracy of resistance measurements.

Further preferably, one end of the guide column is installed on the base plate, and the other end is provided with a mounting bracket for installing the voltmeter and ammeter, so that the structure of the device is compact and the reading of the voltmeter and ammeter is more intuitive. The guide column passes through the adjusting platen and cooperates with the adjusting platen in clearance; the mounting frame is provided with an adjusting nut that passes through the mounting frame and is threadedly engaged with the mounting frame, and the rod of the adjusting nut passes through the Through the adjusting platen, the rod portion of the adjusting nut passes through one end of the adjusting platen to be provided with a limit protrusion, so that the adjusting platen can move up and down along the guide column through the threaded cooperation between the adjusting nut and the mounting frame.

Preferably, a detection electrode installation rod is provided on the adjustment pressure plate, an electrode adjustment block is installed on the detection electrode installation rod, and the electrode adjustment block is transitionally fitted with the detection electrode installation rod, and the detection electrode is installed on the detection electrode installation rod. On the electrode adjustment block, the detection electrode can be moved under the condition of applying force. Further preferably, the scale on the adjustment platen is set on the side of the adjustment platen close to the detection electrode installation rod, so as to facilitate the adjustment of the distance between the detection electrodes.

Compared with the prior art, the utility model has the following advantages:

The resistivity testing device of the utility model comprises a base plate, a fixed frame fixedly arranged on the base plate, a guide column fixed on the base plate, an adjusting pressure plate with a scale arranged on the guide column, and an adjusting pressure plate arranged on the adjusting pressure plate to be used for testing. The detection electrode in contact with the workpiece and the resistance detection device connected to the detection electrode. The workpiece to be tested can choose carbon fiber, etc., and the voltage and current can be measured at the measured length of the required carbon fiber, and the resistivity can be calculated by the formula once. The same carbon fiber can be Measure the voltage and current at different measurement lengths, and calculate the resistivity at different measurement lengths through the formula, so as to ensure the accuracy of the test.

The resistivity testing device of the present utility model, in the preferred scheme, compared with the prior art, such as a universal meter, the resistance detecting device of the present utility model includes a voltmeter and an ammeter, and current terminals are installed at both ends of the fixing frame, and the current terminals are connected to a power supply. , provide current to the carbon fiber under the measurement length through the current terminal, obtain the voltage value and current value through the voltmeter and ammeter, and calculate the resistance of the carbon fiber under the measurement length through the voltage value and current value, which is conducive to improving the accuracy of resistance measurement. In the resistivity testing device of the utility model, the adjusting pressure plate moves up and down along the guide column through the threaded cooperation of the adjusting nut and the mounting frame, and the structure is simple and easy to use. The adjusting pressure plate is provided with a detection electrode installation rod, and an electrode adjustment block is installed on the detection electrode installation rod, which can make the detection electrode on the electrode adjustment block move under the condition of applying force. The structure is simple and easy to use. The scale on the adjustment pressure plate is set on the side of the adjustment pressure plate close to the detection electrode installation rod, so as to facilitate the adjustment of the distance between the detection electrodes.

Overall, the resistivity testing device of the utility model has a simple structure and is convenient to use, and can accurately measure the resistivity of carbon fibers.

Description of drawings

Fig. 1 is a structural schematic diagram of a resistivity testing device of the present invention.

Detailed ways

The following is a further detailed description of the resistivity testing device of the present invention in conjunction with the accompanying drawings.

As shown in Figure 1, it is the resistivity testing device of the present utility model, comprising a base plate 1, a fixed frame 11 fixedly arranged on the base plate 1 for fixing carbon fibers, a guide post 3 fixed on the base plate 1, and a guide post 3 arranged on the base plate 1 An adjustment platen 2 with a scale 8, a detection electrode 10 arranged on the adjustment platen 2 for contacting with carbon fibers, and a resistance detection device connected to the detection electrode 10.

The resistance detection device comprises a voltmeter 7 for detecting the voltage of the carbon fiber under the measurement length and an ammeter 4 for detecting the current of the carbon fiber under the measurement length. A current terminal is installed, and the current terminal is connected with a power supply. The carbon fiber under the measurement length is provided with current through the current terminal, the voltage value and the current value are obtained through the voltmeter 7 and the ammeter 4, and the resistance of the carbon fiber under the measurement length is calculated through the voltage value and the current value, thereby helping to improve the accuracy of resistance measurement. Guide column 3 is two, and guide column 3 one ends are installed on the base plate 1, and the other end is used for installing the mounting bracket 5 of voltmeter 7 and ammeter 4, and guide column 3 passes through adjustment pressing plate 2 and cooperates with adjusting pressing plate 2 gaps. The mounting frame 5 is provided with an adjusting nut 6 that runs through the mounting frame 5 and is threadedly matched with the mounting frame 5. The rod portion of the adjusting nut 6 passes through the adjusting platen 2, and the end of the rod portion of the adjusting nut 2 passing through the adjusting platen 2 is provided with a limit position. The protrusion can make the adjustment pressure plate 2 move up and down along the guide column 3 through the threaded cooperation of the adjustment nut 6 and the installation frame 5 .

The adjustment platen 2 is provided with a detection electrode installation rod 12, and an electrode adjustment block 9 is installed on the detection electrode installation rod 12. There are two electrodes 10, and there are correspondingly two electrode adjustment blocks 9, which can make the detection electrodes 10 move under the condition of applying force. The scale on the adjustment pressure plate 2 is set on the side of the adjustment pressure plate 2 close to the detection electrode installation rod 12, so as to facilitate the adjustment of the distance between the two detection electrodes 10.

The specific working principle of the utility model resistivity testing device is as follows:

Fix the carbon fiber to be tested on the fixed frame 11, and then adjust the distance between the two detection electrodes 10 based on the scale 8 on the adjustment pressure plate 2 as required, and then move the adjustment pressure plate 2 through the adjustment nut 6 to adjust the pressure plate 2 The detection electrode 10 on the top is in contact with the carbon fiber, the resistance value is obtained through the measurement of the resistance detection device, and finally the resistivity of the carbon fiber is obtained through the formula.

Example 1

The resistivity of the carbon fiber is tested by using the resistivity testing device of the utility model. Take a carbon fiber sample of 300 mm, fix it on the current terminal of the fixed frame 11 under the condition of applying a certain tension, adjust the distance between the two electrode adjustment blocks 9 according to the scale line of the scale 8 on the adjustment pressure plate 2, so that the two The distance between the detection electrodes 10 is 85.04mm, adjust the adjustment nut 6, the adjustment pressure plate 2 is gradually lowered until the detection electrode 10 on it touches the carbon fiber sample to be tested; by adjusting the power supply, the current value I of the carbon fiber sample is stabilized at I0 .05A, then read the voltage value at this time.

Calculate the resistivity of the sample to be tested according to the following formula:

${\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; u</span>}}{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; \&times;</span>\frac{\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; L</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 5</span>}}$

In the formula: ρ _f - carbon fiber resistivity, Ω/cm

U—voltage value between electrodes, V;

I—the current value of the carbon fiber, A;

t—the denier of the carbon fiber sample, tex;

ρ—the bulk density of carbon fiber, g/cm ³ ;

L—measured length of carbon fiber (ie 85.04mm).

As mentioned above, the utility model device can be better realized. In order to ensure the accuracy of the resistivity test, the distance between the two detection electrodes 10 (that is, the measurement length of the carbon fiber) can be readjusted, and the voltage and current can be measured at different measurement lengths for the same carbon fiber, and the formula can be used to calculate resistivity, thus ensuring the accuracy of the test results.

Claims (6)

1. a resistivity testing device, is characterized in that, comprises base plate, is fixedly arranged on described base plate and is used for fixing the fixture of test piece, is fixed on the guide column on described base plate, is arranged on described guide column An adjustment platen with a scale, a detection electrode arranged on the adjustment pressure plate for contacting the object under test, and a resistance detection device connected to the detection electrode. 2. The resistivity testing device according to claim 1, characterized in that, the resistance detection device comprises a voltmeter for detecting the voltage of the test piece under the measurement length and a current for detecting the test piece under the measurement length An ammeter, both the voltmeter and the ammeter are connected to the detection electrodes, and current terminals are installed at both ends of the fixing frame. 3 . The resistivity testing device according to claim 2 , wherein one end of the guide column is installed on the base plate, and the other end is provided with a mounting frame for installing the voltmeter and the ammeter. 4 . 4. The electrical resistivity testing device according to claim 3, wherein the guide column passes through the adjusting platen and cooperates with the adjusting platen in clearance; The mounting frame is provided with an adjusting nut that runs through the mounting frame and is threadedly engaged with the mounting frame, the rod of the adjusting nut passes through the adjusting platen, and the rod portion of the adjusting nut passes through the adjusting platen One end is provided with a limit protrusion. 5. The electrical resistivity testing device according to claim 1, characterized in that a detection electrode installation rod is provided on the adjustment platen, an electrode adjustment block is installed on the detection electrode installation rod, and the electrode adjustment block is connected to the electrode adjustment rod. The detection electrode installation rod is transitionally fitted, and the detection electrode is installed on the electrode adjustment block. 6 . The resistivity testing device according to claim 5 , wherein the scale on the adjusting platen is set on the side of the adjusting platen close to the detection electrode installation rod. 7 .

Images