Resistor and Capacitor Codes
First the code
Black

Brown

Red

Orange

Yellow

Green

Blue

Violet

Grey

White

0

1

2

3

4

5

6

7

8

9

How to read the code

 First find the tolerance
band, it will typically be gold ( 5%) and sometimes silver (10%).
 Starting from the other end,
identify the first band  write down the number associated with that
color; in this case Blue is 6.
 Now 'read' the next color,
here it is red so write down a '2' next to the six. (you should have
'62' so far.)
 Now read the third or
'multiplier exponent' band and write down that as the number of zeros.
 In this example it is two so
we get '6200' or '6,200'. If the 'multiplier exponent' band is Black
(for zero) don't write any zeros down.
 If the 'multiplier exponent'
band is Gold move the decimal point one to the left. If the 'multiplier
exponent' band is Silver move the decimal point two places to the left.
If the resistor has one more band past the tolerance band it is a
quality band.
 Read the number as the '%
Failure rate per 1000 hour' This is rated assuming full wattage being
applied to the resistors. (To get better failure rates, resistors are
typically specified to have twice the needed wattage dissipation that
the circuit produces). Some resistors use this band for temco
information. 1% resistors have three bands to read digits to the left of
the multiplier. They have a different temperature coefficient in order
to provide the 1% tolerance.
 At 1% the temperature
coefficient starts to become an important factor. at +/200 ppm a change
in temperature of 25 Deg C causes a value change of up to 1%

Reading Capacitor Values
Large capacitor have the value printed
plainly on them, such as 10.uF (Ten Micro Farads) but smaller disk types along
with plastic film types often have just 2 or three numbers on them?
First, most will have three numbers, but
sometimes there are just two numbers. These are read as PicoFarads. An
example: 47 printed on a small disk can be assumed to be 47 PicoFarads (or 47
puff as some like to say)
Now, what about the three numbers? It is
somewhat similar to the Resistor Codes. The first two are the 1^{st}
and 2^{nd} significant digits and the third is a multiplier code. Most
of the time the last digit tells you how many zeros to write after the first
two digits, but the standard (EIA standard RS198) has a couple of curves that
you probably will never see.
Now for an example: A capacitor marked
104 is 10 with 4 more zeros or 100,000pF which is otherwise referred to as
a .1 uF capacitor.