"Dwell" is simply an average of the voltage available at the points or the downstream side of the coil primary when the points are open, and closed. The term "dwell" is a contraction of the number of degrees of distributor rotation the points "dwell together" (points closed). At that time the voltage that can be measured at the points will be zero, since one side of the points is grounded. When the points are open, there will be a voltage equal to the battery voltage or the charging system. Let's do a little math ;

Battery voltage: 12.6V (running on battery power only)
Total available degrees of dwell: 60 (360 divided by 6)
Specified dwell angle: 32
32 divided by 60 = points are closed 53% of the time
12.6 X .53 = 6.66V
12.6 - 6.66 = 5.94V

When the engine is running with 32 degrees of dwell, an analog voltmeter (NOT DIGITAL) from the above example will read 5.94 volts, as the points will be open 47% of the time. If you have an analog voltmeter, you've also got a dwell meter. Digital meters react too fast to the changes in voltage, and the numbers on the readout will just be random gibberish.
Jerry

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