1、 Preparation before use

1. Check the instrument

   • Visual inspectionConfirm whether the appearance of the tester is damaged, whether the buttons and knobs are normal, and whether the display screen is clear.
   • power checkEnsure that the internal battery of the instrument is fully charged or connected to an external power source (usually AC 220V/50Hz) to ensure that the instrument can function properly.
   • Test line inspectionCheck if there are any open circuits in the current, voltage, and ground wires used for testing. The cross-sectional area of the copper core for current lines should be ≥ 1.5 square millimeters, and the cross-sectional area of the copper core for voltage lines should be ≥ 1.0 square millimeters.

2. Prepare auxiliary equipment and tools

   • Prepare corresponding auxiliary equipment according to the testing method, such as current poles, voltage poles, testing lines, etc., and ensure that these devices are intact and undamaged.
   • Clean the rust on the ground stake and ensure that it is buried at a suitable depth (generally greater than 0.5 meters).

3. Understand the testing environment

   • Understand the basic situation of the tested grounding network, including the layout of the grounding network and the surrounding environment. Determine whether there are factors that may affect the test results, such as whether there are strong electromagnetic interference sources nearby, whether there are metal pipelines underground, etc.

2、 Wiring operation

1. Current pole and voltage pole settings

   • Current poleMaintain sufficient distance from the tested grounding grid, generally 4 to 5 times the maximum diagonal length of the tested grounding grid.
   • Voltage poleThe distance between the current pole and the tested grounding grid is generally 0.618 times the distance between the current pole and the tested grounding grid.

2. Test line connection

   • Current lineConnect the current output terminal (C) of the tester to the current pole through the test line.
   • voltage lineConnect the voltage input terminal (P) of the tester to the voltage pole through the test line.
   • Ground network cableConnect the grounding terminal (E) of the tester to the grounding body of the tested ground grid reliably using a test line.
   • Precautions：
     • The current testing line and voltage testing line cannot be tangled together, otherwise it may affect the testing accuracy.
     • The current test line and voltage test line are placed parallel and kept at a certain distance to reduce the impact of mutual inductance coupling on the test results.

3、 Parameter settings

1. Select measurement mode

   • According to the testing requirements, select the corresponding measurement mode on the tester, such as ground resistance measurement, soil resistivity measurement, etc.

2. Set measurement frequency

   • Some testers have multiple measurement frequencies to choose from, generally selecting frequencies that are suitable for the on-site interference situation to improve anti-interference ability. Usually, frequencies such as 45Hz or 55Hz that have a certain difference from the power frequency can be selected.

3. Set measurement range

   • Select an appropriate measurement range based on the estimated grounding resistance value to ensure the accuracy and precision of the measurement results. If the range of resistance values is uncertain, a larger measurement range can be selected for preliminary measurement, and then adjusted to an appropriate range based on the measurement results.

4、 Start measurement

1. Confirm that the wiring is correct

   • Before starting the measurement, confirm again whether all wiring is correct and whether the connection between the test line and the ground stake is conductive.

2. Start measurement

   • Press the measurement button of the tester, and the tester will inject a certain frequency and magnitude of current into the tested grounding grid, measure the corresponding voltage, and calculate parameters such as grounding resistance.
   • During the testing process, the tester will display the testing progress and related information.

5、 Read and record data

1. Read data

   • After the measurement is completed, data such as grounding resistance and soil resistivity will be displayed on the screen of the tester.
   • According to the testing requirements, other relevant parameters such as current and voltage can also be read.

2. record data

   • Record the measured data, including grounding resistance value, soil resistivity, testing time, testing location, measurement method, and other relevant information.
   • Some testers support automatic printing function and can directly print test reports.

6、 Data Processing and Analysis

1. data processing

   • Process and analyze the recorded data according to the measurement purpose and requirements. For example, calculating statistical parameters such as mean and standard deviation, and plotting the variation curve of grounding resistance over time or position.

2. Result Analysis

   • Evaluate whether the grounding performance of the grounding system meets relevant standards and requirements.
   • If abnormal or non compliant grounding resistance values are found, the cause should be promptly identified and corresponding measures taken.

7、 Precautions

1. safe operation

   • During the testing process, the personal safety of the testing personnel should be ensured to avoid accidents such as electric shock.
   • Before testing, the connecting wire between the tested grounding electrode and the protected electrical equipment should be disconnected to prevent the testing current from affecting the equipment.

2. Correct wiring

   • Ensure that the test line is connected correctly to avoid incorrect test data caused by reverse connection or poor contact.
   • During the testing process, it is necessary to avoid contact between the testing line and other metal conductors to prevent the introduction of interference signals.

3. environmental interference

   • During testing, strong electromagnetic field interference should be avoided as much as possible to avoid affecting the accuracy of the test results.
   • If there is strong electromagnetic interference in the testing environment, corresponding shielding measures can be taken.

4. instrument maintenance

   • Regularly calibrate and maintain instruments to ensure their accuracy and reliability.
   • If the instrument malfunctions or has abnormal conditions, the manufacturer or professional maintenance personnel should be contacted in a timely manner for maintenance.

Through the above steps, you can correctly use the digital earth network tester to measure parameters such as grounding resistance and soil resistivity. In practical operation, it is recommended to strictly follow the instructions of the instrument to ensure the accuracy and reliability of the measurement results.