The direct current resistance tester mainly adopts the top-opening or vehicle-mounted structure, specially designed for production and on-site test field operators. It uses a large screen LCD Chinese display, suitable for continuous testing of multi-tap load switches without interruption, dynamic prompts during the measurement process, automatic arc current indication and sound and light indication alarm, and test records can be edited and saved with user information, printed.

　　To ensure the effectiveness of the direct current resistance tester, users need to operate it according to the normal method. Let's take a detailed look at this below:

　　When measuring the windings of the same phase of the same transformer at the same voltage level, it is necessary to select the same current for measurement to avoid systematic errors. The larger the capacity of the transformer, the smaller the resistance of the winding, and the larger the test current selected. Note that the measuring range of the selected test current should be greater than the actual resistance value. After pressing the "measure" key, the test begins. At this time, the screen displays "charging", and a charging progress bar appears to show the charging process. When the charging is completed, the screen prompts "measuring, please wait", and the display area in the middle of the screen displays the measured resistance value. After the reading stabilizes, read the value, and then you can press the "store" key to store the measurement data or press the "print" key to print the data as needed.

　　If the measured resistance exceeds the range that the current range can measure, the screen prompts "over range". At this time, the "exit" key should be pressed to exit the measurement, and then the test current should be re-selected and tried again.

　　End of measurement:

　　After the no-load voltage regulator transformer has been tested for a certain tap, the "exit" key of the instrument needs to be pressed, and the discharge indicator needs to be waited for to complete, and then the tap switch needs to be adjusted for the next measurement.

　　For a loaded tap changer transformer, after measuring a certain tap, there is no need to discharge, directly adjust the loaded tap changer switch, and then press the "re-test" key of the instrument, the instrument will measure the next tap, greatly shortening the measurement time.

　　After the measurement, press the "Exit" key. The machine will then close the output and return to the initial state. Wait for the next measurement. If it is an inductive load, it will enter the discharge state, and the discharge information will be displayed on the screen at this time. After the discharge is completed, it will return to the measurement menu and wait for the next measurement. The discharge time depends on the inductance of the test item.

　　Note: When measuring inductive loads, do not directly remove the test leads, as this may endanger the safety of the test personnel and equipment due to inductive discharge. The output end of this machine is equipped with a discharge circuit. When the output is turned off, the inductance will discharge energy through it. The test leads must be removed only after the discharge indicator has finished.