The ohm gear of the multimeter is broken, how to repair it
1. The first is to directly measure the resistance, let's talk about the traditional multimeter first. Turn the pointer to the gear as shown in the picture (ohm gear Ω). This is the gear for measuring resistance.
2. The starting position 0 of the current and voltage readings is on the left, and the starting position 0 of the resistance is on the right. Find the dial line of the resistance reading, and the reading will be read from here later.
3. Connect the two nibs of the multimeter and see if the pointer points to the 0 position. If the multimeter does not have a mechanical adjustment, turn it to zero (if it cannot be adjusted to 0, the battery is dead)
4. Place the two nibs at both ends of the resistance to measure the reading. At this time, the resistance value is read out. This method cannot measure the insulation resistance. Resistance value = gear position × reading For example, the gear position is 100Ω and the reading is 30, which is 3K ohms.
5. The digital type is simpler, just set the gear to the ohm range and read.
Measuring Power Supply Resistance
1. To measure the power supply resistance, an auxiliary resistor is required, and the auxiliary resistor can also be an incandescent bulb (leds are not acceptable). First, measure the resistance value of the resistor and record r1 according to the above method.
2. Turn the multimeter to the DC voltage range, measure the voltage of the power supply, and record the resistance value v1
3. Connect the power supply and the resistor to measure the voltage v2 applied to the resistor.
4. The resistance of the power supply = r1×v2÷v1. This gives the power supply resistance.
See measuring electrical indirect
1. From the above method, it can be compared to how to measure resistance indirectly. If you know a resistor with a known resistance value, and then measure the voltage of one resistor and then measure the voltage of another resistor in series, it can be calculated by the above calculation method.
2. Another is to connect the resistor to the power supply to measure the voltage and current respectively, and divide the voltage by the current to calculate the resistance value. These will not be detailed one by one.
Multimeter measuring resistance 200 megohm short circuit does not return to zero normally
Normal, no matter what kind of digital meter, 20MΩ or 200MΩ, that is to say, the electric resistance of more than 20MΩ is considered high resistance, and the high resistance short-connected test pen shows 0.9 under normal circumstances, and it is normal under normal circumstances. Shorting the test lead 0.9 is not considered a fault. Because 200MΩ is a high barrier.
Steps for measuring resistance with a digital multimeter
Step 1: Insert the black test lead into the "COM" hole, and the red test lead into the "VΩ" hole;
Step 2: Select an appropriate resistance range, and connect the black test lead and the red test lead to both ends of the resistance respectively. Be careful not to touch both ends of the resistance with your hands at the same time. Since the human body is a large resistance conductor, doing so will affect the measurement of resistance. accuracy;
Step 3: Combine the data displayed on the display with the resistance range to get the final measurement result.
