140CPU65260 Digital megohm meter range selection tips, secrets you need to know!
The method of using a digital megohm meter is as follows:
Step 1:140CPU65260 Preparations Before performing the operation, ensure that the electrical device to be tested has been powered off and fully discharged to ensure the safety of the operation. In addition, it is also necessary to check whether the power of the digital megohm meter is enough, whether the appearance is intact, and ensure that the display screen works normally.
Step 2: Wiring A digital megohm meter usually has three terminals, namely L (line end), E (ground end) and G (shield end). Connect the L terminal to the wire portion of the device under test, and connect the E terminal to the housing or ground of the device. If the device under test has a shielding layer, connect the G terminal to that layer to reduce the impact of external interference.
Step 3: Select the range Select the appropriate range according to the insulation class of the device under test and the expected resistance value. Typically, digital megohm meters offer multiple ranges for the user to choose from. In the selection, it should start with a higher range and gradually reduce to avoid excessive reading errors due to the selection of too high range.
Step 4: 140CPU65260 START measuring After setting the measuring range, press the “TEST” or “Start” button to start measuring, the screen will display the value of insulation resistance in real time.
Step 5: Observe the reading Pay attention to observe whether the reading is stable. For devices with large capacitors, it is necessary to wait for some time to ensure that the capacitor is fully charged and that a stable reading is obtained.
Step 6:140CPU65260 Record data When the reading is stable, record the value of the insulation resistance. If the megohm meter has an automatic locking function, it can be used to lock and read the maximum resistance value.
Step 7: 140CPU65260 The end of the test After the completion of the measurement, the megohm meter should be disconnected from the device under test, and then turn off the megohm meter power supply or exit the measurement mode. During the entire test process, the operator should wear insulated gloves to ensure personal safety. At the same time, the equipment under test should be fully discharged before contact and operation.