The “Time/Div.” wheel determines, how long the electronic beam that draws the curve takes for moving from the left to the right edge of a division. The wheel controls the “time scale”. A “division” is one square on the screen of the oscilloscope.
For example if the wheel is set to “1 ms”, 1 ms passes until the beam moves through the division horizontally, i.e. it needs 10 ms for moving the beam from the left to the right edge of the screen, because the surface is divided into 10 divisions. “Surface” in this context means the whole movement range of the beam, because in “X-Mag.” mode the surface is stretched 10 times its original size.
The horizontal frequency in that example would be 1/1 ms = 1000 Hz, this means the electronic beam moves 1000 times a second from the left to the right edge of the screen. The observer sees a flicker-free, seamless image. In longer “Time/Div.” settings however the movement of the electronic beam becomes visible. In the simulation longer “Time/Div.” settings can only be displayed with some quality restrictions, because the calculation power of the Macromedia scripting language “Lingo” in connection with current processor speeds is not good enough to do the full realtime calculation.
The “Time/Div.” wheel is made up of two wheels:
The big wheel is a coarse setting of previously calibrated values. To obtain the calibrated values, the small wheel rotation must be set to its left edge.
With the small wheel, located on top of the big wheel, a fine adjustment can be made. The small wheel is only calibrated for its leftmost position.