How to use a multimeter: measuring resistance

How to use a multimeter to measure resistance? Multimeters are divided into digital multimeters and traditional multimeters with electromagnetic deflection of pointers. Digital multimeters are more expensive and need to be used with batteries, but they are convenient to read. Multimeters measure current. Traditional multimeters measure resistance and also need batteries, but in some cases, other methods can be used to indirectly measure resistance. Let's talk about it below.
First, directly measure resistance. Let's talk about traditional multimeters first. Set the pointer to the position shown in the figure (Ohm gear Ω). This is the gear for measuring resistance. The starting position 0 of the current and voltage readings is on the left, while the starting position 0 of the resistance is on the right. Find the reading dial line of the resistance, and read the reading from here later. Connect the two pen tips of the multimeter and see if the pointer points to the 0 position. If the multimeter does not have a mechanical adjustment place, turn it to make it return to zero (if it cannot be adjusted to 0, it means that the battery is dead). Place the two pen tips at both ends of the resistor and measure the reading. At this time, the resistance value is read. This method cannot measure insulated resistance. Resistance value = gear × reading, for example, if the gear is 100Ω and the reading is 30, then it is 3K ohms. Digital is simpler, just set the gear to the ohm gear and read the reading.
Measuring power supply resistance
Measuring power supply resistance requires an auxiliary resistor, which can also be an incandescent bulb (LED is not acceptable). First, measure the resistance of the resistor according to the above method and record r1. Set the multimeter to the DC voltage gear, measure the voltage of the power supply and record the resistance value v1, connect the power supply and the resistor to measure the voltage v2 applied to the resistor. The resistance of the power supply = r1×v2÷v1. In this way, the resistance of the power supply is obtained.
How to measure resistance with a multimeter? For this problem, the above method can be used to analogize how to measure resistance indirectly. If you know a resistor with a known resistance value, then measure the voltage of one resistor and then measure the voltage of another resistor according to the series method, and you can calculate it using the above calculation method. Another way is to connect the resistor to the power supply to measure the voltage and current respectively and calculate the resistance by dividing the voltage by the current. These will not be described in detail one by one.