Stroke speed

Stroke speed: In facsimile systems, the rate at which a fixed line perpendicular to the direction of scanning[?] is crossed in one direction by a scanning or recording spot[?].

Note 1: Stroke speed is usually expressed as a number of strokes per minute. When the system scans in both directions, the stroke speed is twice this number.

Note 2: In most conventional mechanical systems, the stroke speed is equivalent to drum speed[?].

Source: from Federal Standard 1037C and from MIL-STD-188