How do you measure the tolerance in Capacitors & Resistor?

Question

How do you determine if a capacitor or resistor is out of its percentile tolerance Example 5uF +/-5%. Is there a formula for this?

Answer 1

Based on your example of a capacitor that is supposed to be 5uF +/- 5%, 5% tolerance on the capacitor would just be 5uF x 0.05 = 0.25uF. So this capacitor should be between 4.75uF and 5.25uF. The best way to determine if the capacitor is in this range is to measure the capacitance with an LCR meter or Digibridge.

To determine what the tolerance of a specific sample actually is, just measure the part's value and then compare this value to the nominal value. For example, if your 5uF capacitor measures something drastic like 6uF, then that specific sample is +20% (6uF-5uF = 1uF, then 1uF/5uF = 0.2 = 20%).
So a formula would be [(measured value - nominal value)/nominal value] x 100. So if the capacitor measured 4.5uF, the tolerance for that sample is [(4.5uF-5uF)/5uF] x 100 = -10%.

So you can't really "measure" the tolerance of a resistor or capacitor, you can only measure the resistance or capacitance and then calculate the tolerance for that specific sample based on the nominal value for that part, as shown above.

To find out what the tolerance of a part SHOULD be, for capacitors, typically the tolerance is not shown on the device package. Usually you need to go to the manufacturer's data sheet. For resistors, many banded or striped resistors have a stripe that signifies what the tolerance of the part should be.
It is typically the 4th stripe that signifies the tolerance. Instead of typing out the meaning of the colors of the stripe, see here:
http://en.wikipedia.org/wiki/Electronic_color_code
Some striped resistors do not show their tolerance with a band, and there are many resistor types that do not have stripes at all. In most of these cases, you will need to see the manufacturer's data sheet for what the tolerance on the part should be.

Answer 2

This Site Might Help You.

RE:
How do you measure the tolerance in Capacitors & Resistor?
How do you determine if a capacitor or resistor is out of its percentile tolerance Example 5uF +/-5%. Is there a formula for this?

Answer 3

Resistor Tolerance Calculator

Answer 4

you measure it on either a capacitor checker or on an impedance bridge... then compare that with the tolerance band on the cap. or resistor.

Use your measurement and the marked value of the component to figure the percentage of tolerance... you DO know how to figure percentages, I hope.

Answer 5

You cannot measure "tolerance" directly, as that is determined by statistical methods in manufacturing.

What you measure is the value of the device and compare it with the listed tolerance. In your example, the 5 uF capacitor may be any value in the range from 4.75 uF to 5.25 uF. That is: 5 uF * 0.95, to 5 uf * 1.05 .

If you happen to find a lot (as in a bulk amount of parts from the same manufacturing run; dated, and coded) of parts that are all (or mostly) out of tolerance, you should contact the manufacturer directly, or through your distributor, for a refund or replacement.

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Answer 6

Thank you! very valuable information and gives me better knowledge on this topic