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Resistance Measurements and Resistor Color Codes Lab


1. To identify resistor values and tolerances from the color code and measurement.

2. To learn to use the ohmmeter to measure resistance and continuity.

3. To compare the color coded resistor tolerance with the actual measured resistance value.

Note: Two measurement devices are preferred so the student can see the variation in the measured values.

1. Digital Multimeter
2. Analog Multimeter (if available)
3. Assorted Resistors


1. Determine the upper and lower limits of each resistor in the Table 1 and record the limit values.

2. Using the DMM, measure the resistance of one resistor of each value. Compare the measured value to the nominal value and calculate the percent error and record the percent error on Table 1. Note whether it is within the 5% tolerance range.

3. Using at least one other meter, measure the resistor again and compare this reading to the DMM. Calculate the percent error and record it on Table 1.

4. Indicate which resistor measurements are in tolerance and which, if any, are not. Show your calculations neatly on a separate piece of paper.

Note: For the DMM measurement,

percent error = Rmeasured - Rnom / Rnom

Table 1: Resistor Measurements

Procedure & Data:

For VOM measurement take DMM measurement at Rnom

(10.1Ω - 10Ω / 10Ω) x 100% = 1.0% in tolerance for DMM

(12.0Ω - 10.1Ω / 10.1Ω) x 100% = 18.812% not in tolerance for VOM

All of the resistors were in tolerance for the DMM, the 10Ω , 47Ω , 220Ω , 470Ω , 2.2kΩ , and 4.7kΩ resistors were not using the VOM.

Table 2: Measured Resistor Values

Conclusion & Discoveries:

1. All resistors were within the 5 percent tolerance if measured from the DMM.

2. 6 out of 13 of the resistors were off when compared from the DMM values and those of the VOM.

3. VOMís are generally less accurate them DMMs, because VOMs can be difficult to read accurately to the tolerances specifications of the resistors.

Electrical Engineering lab key words: Measuring Resistors, .25watt, Power, Resistor Color Codes, Resistor Measurements, Resistance Measurement, Digital Multimeter, Ohm Measurement, DMM, Meters, Percent Error and Resistor Tolerance, Electrical Engineering Lab Experiment.

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