How to measure the resistance to the multimeter

The theme of our article is the measurement of resistance. Resistance will be measured using a multimeter measuring instrument. Resistance is measured in Omah, kiloma, megaoms.

1
What is an Ommeter?

So, let's in more detail on the one represents an ohmmeter. Ommeter is a measuring device that serves to determine the amount of resistance in electrical circuits. The resistance is indicated by the Latin letter R on electrical circuits. Measure resistance under voltage is strictly prohibited. Before measuring any resistance it is necessary to check the device itself.

2
How can you check it?

Resistance can be measured at the multimeter. To do this, set the minimum value at the multimeter, in our example it is 200 ohms, and closing the contacts of the device. Ideally, the device must show a very low value. In our example, the device shows a value of 0.02.

3
How to measure resistance of different devices?

To measure resistance as an example, take a fuse. The fuse with us is designed for 100 amps. We measure the resistance of the insert. To do this, touch the fuse contacts. Resistance is equally practically resistance to probe. Very minimal resistance.

Next, measure the resistance of the coil. The coil from the magnetic starter. The coil voltage is 380 volts, the frequency is 50 hertz, the number of turns of 4900, the diameter of the wire is 0.160. When measuring the resistance, the device does not show us the resistance value. The reason is that the resistance of the coil is greater than the magnitude that we installed by default on the multimeter. For this reason, we should switch the device for 2 kiloma. After switching the instrument for 2 kiloma, we make measurements with you and the device shows us that the resistance is 439.

We measure the resistance of the transformer winding: the resistance of the primary side, the secondary side. On the primary side, our suitable voltage is 380 volts. We measure the resistance, install the constant initial value of 200 ohm at the multimeter, we measure the resistance of the primary side. And the multimeter shows us the winding resistance of 17.4 Ohm.
We measure the resistance of the wire on a voltage of 24 volts. Resistance is 0.6 ohms, that is, an order of magnitude lower. The lower the voltage class, respectively, fewer turns of the winding and, accordingly, the winding resistance will be much smaller. Let's check for 5 volts. The resistance is 0.3 ohms, that is, almost close resistance to the impassion resistance.
Next, let's measure 22 volts resistance. The resistance increases. Also measurable resistance to a voltage of 110 volts. The wire resistance is 4.10 ohms, that is, with an increase in voltage, the number of turns of the transformer winding increases. Thereby rises resistance.

As an example, let's still measure the resistance of the usual incandescent bulb. The light is designed for voltage drop to 225 volts, power 40 watts. When measuring, the bulb resistance is 94.4 Ohm.