CN204855770U - Concrete resistivity apparatus calibrating device - Google Patents

Abstract

The utility model discloses a calibration device for a concrete resistivity measuring instrument, which comprises a box body with a control panel on the surface, and a resistivity calibration system is arranged in the box body; four calibration contacts arranged in a straight line and at least 4 calibration contacts are installed on the control panel Gear switch; the resistivity calibration system includes at least 4 sets of calibration circuits; each set of calibration circuits includes three control circuits; each control circuit includes a synchronous switch and a resistor connected in series; each control circuit is connected to any phase Between two adjacent calibration contacts; the resistance of the three resistors in the same group of calibration circuits is the same; when each gear switch is closed/open, it can simultaneously control the three synchronous switches in the group of calibration circuits to be closed/off open. The beneficial effects achieved by the utility model: by setting multiple gears, the resistivity of different ranges can be accurately calibrated step by step, and the calibration range can reach 4~2000kΩ·cm; a higher resistivity test can also be set according to the actual situation range and more calibration points.

Description

Calibration device for concrete resistivity meter

technical field

The utility model belongs to the technical field of instrument and equipment verification, and in particular relates to a calibration device for a concrete resistivity measuring instrument, which is suitable for the calibration of the reinforced concrete resistivity measuring instrument by the production enterprises, users and measurement technical institutions of the reinforced concrete resistivity measuring instrument and quality testing.

Background technique

The corrosion of steel bars in concrete is a phenomenon caused by an electrochemical action, which will generate an electric current to corrode the steel bars. Therefore, it can be inferred whether the steel bars are corroded by testing the resistivity of the concrete. Resistivity is a very important parameter for reinforced concrete as a building material. It is easy to obtain by simple test methods. It can directly reflect the corrosion of steel bars, and can also be well established with other properties of concrete. It is a reflection of concrete. An important basis for quality status. The method of measuring concrete resistivity by this instrument is simple, fast and easy to operate, and it is expected to become a new non-destructive testing technology for concrete and be applied in concrete engineering. Therefore, scientific and accurate detection methods are not only of great significance for the determination of resistivity and internal corrosion, but also for the accumulation of experience in reinforced concrete engineering, building construction and materials, and are of great significance in construction engineering and safety.

Concrete resistivity tester is an instrument used to measure concrete resistivity, it can be used to measure the electronic impedance on the surface of concrete body 3 and detect the corrosion status of reinforced concrete structures. At present, the commonly used resistivity tester is the four-probe resistivity tester (hereinafter referred to as the resistivity tester), which mainly includes basic electrical equipment, probes and displays. The electrical part generally includes adjustable steady current sources, A/D converters, digital displays, reversing switches and other instruments and components. The probe part is composed of sensors, and the sponge must be soaked and stuffed into the sensor hole for use. The test schematic diagram is shown in Figure 1: Apply current I to the outer electrode, the current flows in from a, and returns from b, at this time, the current field generated by the outer electrode generates a potential on the inner electrode. Use a potentiometer or a high-resistance voltmeter to measure the potential difference between the inner electrodes c and d, and U/I is the grounding resistance. The calculation formula of resistivity is: ρ=RS/L. Among them, ρ is the resistivity (kΩ·cm); S is the cross-sectional area of the wire (m ² ); R is the resistance value (Ω); L is the length of the wire (m). According to Figure 1, it can be deduced that ρ=2πR/(1/a ₁ -1/a ₂ -1/a ₃ +1/a ₄ ). The schematic diagram of the measurement is shown in Figure 2. During the measurement, the four-electrode probes are filled with soaked sponges and pressed against the surface of the concrete body 3 to be measured. The resistivity value of the measured object can be read from the display of the instrument host.

The resistivity tester plays an important role in the determination of the internal corrosion of concrete and the monitoring of building safety. Whether the instrument itself is accurate is also important. However, there is no one that can calibrate the accuracy of the full measurement range of the four-probe resistivity tester. Calibration device, unable to calibrate the resistivity meter.

Utility model content

The utility model provides a calibrating device for a concrete resistivity measuring instrument, which is simple in structure, easy to carry, accurate in calibration, and capable of calibrating concrete resistivity measuring instruments with different measuring ranges.

The technical solution of the utility model: a concrete resistivity measuring instrument calibration device, including a box body with a control panel on the surface, a resistivity calibration system is arranged in the box body; four linearly arranged calibration contacts and At least 4 gear switches; the resistivity calibration system includes at least 4 sets of calibration circuits; each set of calibration circuits includes three control circuits; each control circuit includes a synchronous switch and a resistor connected in series; each set of calibration circuits The three control circuits are respectively connected between any two adjacent calibration contacts, and the resistance values of the three resistors are the same; when each gear switch is closed/disconnected, it can simultaneously control the three synchronization circuits in the group of calibration circuits. Switch on/off.

In the utility model, the gear switches are sequentially arranged on the control panel according to the calibration range from small to large, and the sum of the corresponding resistance values in the calibration circuit also increases sequentially.

In the utility model, the number of gear switches is 8, and the number of corresponding calibration circuits is 8 groups.

In the utility model, a cover body is also included, and the cover body is hinged on the side wall of the box body, and the cover body can cover or expose the control panel when rotating.

In the utility model, the four calibration contacts are arranged equidistantly.

The beneficial effects achieved by the utility model:

1. By setting multiple gears, the resistivity of different ranges can be accurately calibrated step by step, and the calibration range can reach 4~2000kΩ·cm; a higher resistivity test range can also be set according to the actual situation, and its parameters can be traced to national benchmark.

2. The resistance values of the resistors in each calibration circuit are equal, and can be set or replaced as required, so as to facilitate the calibration of resistivity in different ranges.

3. After use, the control panel can be covered by putting down the cover to prevent it from being damaged by dirt and external impact, and prolong the service life of the device.

4. The calibration contacts are equidistantly arranged in a straight line, corresponding to the probes of the existing four-probe resistivity tester, which is more convenient for operation. In addition, the equidistant setting is also conducive to calculation, which improves the calibration accuracy and shortens the calculation time. .

5. The device has simple structure, precise calibration, and is easy to carry and operate.

Description of drawings

Accompanying drawing 1 is the mensuration schematic diagram of four-probe type resistivity measuring instrument;

Accompanying drawing 2 is the measurement schematic diagram of four-probe type resistivity measuring instrument;

Accompanying drawing 3 is the structural representation of the utility model;

Accompanying drawing 4 is the work flowchart of the present utility model;

Accompanying drawing 5 is the circuit connection diagram of the present utility model.

Reference signs:

1 resistivity tester; 2 probe; 3 concrete body; 4 box body; 5 control panel; 6 calibration contact; 7 gear switch; 8 cover body; 9 synchronous switch; 10 resistance.

Detailed ways

The technical scheme of the utility model will be further described in detail below in conjunction with real-time examples and accompanying drawings, but the protection scope of the utility model is not limited to the described embodiments.

As shown in Figures 3 to 4, a concrete resistivity meter calibration device includes a box body 4 with a control panel 5 on the surface, and a resistivity calibration system is arranged inside the box body 4. The control panel 5 is equipped with four calibration contacts 6 arranged in a straight line and equidistantly corresponding to the probes 2 of the four-probe resistivity measuring instrument 1 and eight gear switches 7 . The calibration contact 6 is sequentially divided into a first contact, a second contact, a third contact and a fourth contact. The eight gear switches 7 are arranged in descending order according to the calibration range.

As shown in Figure 5(a), the resistivity calibration system includes 8 sets of calibration circuits, which are set up in ascending order of the calibration range, and each gear switch 7 controls the conduction of the corresponding calibration circuit. As shown in Figure 5(b), the components and connection methods of each calibration circuit are the same. Specifically, the first calibration circuit includes three control circuits, which are the first control circuit, the second control circuit and the third control circuit in turn. . Each control circuit includes a resistor 10 and a synchronous switch 9 connected in series. The first control circuit is connected in series between the first calibration contact and the second calibration contact; the second control circuit is connected in series between the second calibration contact and the third calibration contact; the third control circuit is connected in series at the between the third calibration contact and the fourth calibration contact. The resistance values of the three resistors in each set of calibration circuits are the same. By analogy, the connection and composition of the other seven calibration circuits are the same. According to the change of the calibration range, the resistance value in the calibration circuit also increases sequentially, that is, the resistance value in the calibration circuit used to calibrate the maximum range resistivity is the largest, while the resistance value in the calibration circuit used to calibrate the minimum range resistivity is the smallest.

Each gear switch 7 controls the three synchronous switches 9 corresponding to the set of calibration circuits. When a gear switch 7 is pressed, three synchronous switches 9 in the calibration circuit under this gear are all closed simultaneously, and the calibration circuit is connected.

In order to protect the internal circuit of the box body 4 and the relevant contacts from being damaged by fouling and external force, a cover body 8 is hingedly installed on the box body 4, and the cover body 8 can cover the control panel 5 by turning downward; The control panel 5 is exposed for work.

Working process and principle of the present utility model:

The calibration process is shown in Figure 4, step 1), calibration device adjustment: place the calibration instrument stably, open the cover 8, expose the control panel 5 and keep it stable.

Calibration of the tested resistivity measuring instrument 1: step 2), operate the four probes of the tested instrument to aim at the four calibration contacts 6 on the panel of the calibration device, and the two are in full contact. Step 3), select the resistivity value to be calibrated, select the corresponding gear switch 7, and adjust the calibration device to the working state. Step 4), select the calibration range, press the gear switch 7, and observe the resistivity degree on the display of the recorder after stabilization, repeat this step several times to obtain multiple sets of data, step 5), and then select the next gear Take measurements. After the calibration is completed, sort the measured data, and finally complete the calibration, otherwise it will return to step 3). Comparing the calibration value with the resistivity standard value, the indication error of this calibration point can be obtained, as shown in the following formula:

Δ=ρ-ρ ₀ ;

In the formula: Δ is the indication error; ρ is the reading of the tested resistivity meter; _ρ0 is the standard resistivity value of the calibration device.

The above-mentioned embodiment is a preferred implementation mode of the present utility model, but the implementation mode of the present utility model is not limited by the above-mentioned embodiment, and any other changes, modifications and substitutions made without departing from the spirit and principle of the present utility model , combination, and simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present utility model.

Claims (5)

1. a concrete resistivity analyzer calibrating installation, is characterized in that: comprise the box body that there is control panel on surface, be provided with resistivity calibration system in box body;

Control panel is provided with calibration touch point and at least 4 driving switch of four line spread; Resistivity calibration system comprises at least 4 group calibration circuits; Often organize calibration circuit and comprise three control circuits; Each control circuit comprises a synchro switch and a resistance and both series connection; Often three control circuits organized in calibration circuit access between two calibration touch point of arbitrary neighborhood respectively, and the resistance of three resistance is identical; Three synchro switches that can simultaneously control when each driving switch closes/disconnects in this group calibration circuit close/disconnect.

2. a kind of concrete resistivity analyzer calibrating installation according to claim 1, is characterized in that: driving switch is arranged in order on the control panel from small to large according to calibration range, and the substitutional resistance value in corresponding calibration circuit also increases successively.

3. a kind of concrete resistivity analyzer calibrating installation according to claim 1 and 2, is characterized in that: the quantity of driving switch is 8, and the group number of corresponding calibration circuit is 8 groups.

4. a kind of concrete resistivity analyzer calibrating installation according to claim 3, it is characterized in that: also comprise lid, lid is hinged on the sidewall of box body, can cover or expose control panel when lid rotates.

5. a kind of concrete resistivity analyzer calibrating installation according to claim 4, is characterized in that: four calibration touch point equidistant arrangement.