SECTION 3. PRINCIPLES OF OPERATION

PRINCIPLES

OPERATION

3-1.BASIC STROBOSCOPE OPERATION.

3.1.1 WHAT IS A STROBOSCOPE

A stroboscope is a source of flashing light that can be synchronized

with any fast, repetitive motion so that a rapidly moving device seems to

stand still, or to move slowly.

To illustrate this principle, consider the following example:

Assume a white disc, with a single black dot, mounted on

the shaft of an 1800 -rpm motor.

When the disc is rotating at 1800 rpm, it is impossible for

the human eye to distinguish a single image and the dot

will appear to be a blurred continuous circle.

When illuminated by the flashing stroboscope light, syn-

chronized to flash once every revolution of the disc (when

the dot is at 3 o`clock, for example), the dot will be seen

at this position and only at this position at a rate of

1800 times each minute. Thus, the dot will appear to

"freeze" or stand still.