How To Use a Digital Multimeter to Test a Resistor

Measuring the resistance of a resistor using a digital multimeter is convenient and easy to do even if the readings may not be that easy to take when the resistance is high, or the measurements you need to take are so close together. The main idea is that the digital multimeter will place a voltage on the two probes. This will make current to flow through the resistor to measure its resistance. Here are some ways on how to use a digital multimeter.

  • Purchase a digital multimeter. It is important to go to a reputable hardware store so that you will be able to buy good hardware. Be sure also to go over the user's manual so that you will have a quick reference if you have some questions in mind.
  • Take some precautions. It is important to do some precautionary measures so that there will be no damage to you or your multitester. You have to measure the resistance of a resistor when they are not in a circuit connection. All the other components will have an effect on the measurement if the resistor is in circuit. Ensure that the circuit is not powered on when it is really necessary to measure resistance that is in a circuit. Turning on your circuit will cause damage to your multitester and might even result in injury. Make sure also that the capacitors are discharged when measuring a resistor in a circuit since these can alter the measurement of the resistor in a circuit.
  • Connect the probes to the digital multimeter. Make sure you don't touch the resistor with your hands. A resistance path can be made through the fingers and can measure a few megaohms, which can affect the measurement significantly. So, it is important to check and not measure your resistance too. You have to connect the black probe to the common port. The red probe shall be connected to Ohm port (marked with the Ohm symbol).
  • Use alligator clips in order to connect the probes of your digital multimeter. These will help you work without touching the resistor (and prevent leakage through your fingers.) This will also give you a better measurement of the resistor. Make sure to match the red and black alligator clips to their corresponding probes. These are then connected to the terminals of your resistor. Remember that the common resistors have four colored bands. The first two bands show the values, the third shows the multiplier and the fourth shows the percent tolerance that the resistor can handle.
  • Measure the resistance of your resistor. Set the dial of the digital multimeter to Ohms. Most digital multimeters have auto ranging, therefore showing the multiplier on the screen together with the reading. Your resistor is ready when you see that the measurement is within the value of 5% of the total variance of 2700 Ohms.

Testing your resistor is made easy with the use of your digital multimeter, and with the right precautionary actions. You must always be careful when dealing with electronic devices so that you will also be safe.


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