Tektronix 475A - Time Comparison Measurements

TIME COMPARISON MEASUREMENTS
If comparisons of an unknown signal with a reference
signal are repetitious (e.g., on assembly line test) it is
possible to obtain more accurate, easily read
measurements if the VAR TIME/DIV control is adjusted to
set the reference signal to an exact number of divisions.
The unknown signal can then be quickly and easily
pared with, or adjusted to, an exact number of
„unknown signals may be measured without
g the setting of the VAR TIME/DIV control by
ing a horizontal conversion factor and an ar-
bitrary “deflection factor. The time duration of the
reference signal must be known before a horizontal
conversion factor can be established.
Determine the horizontal conversion factor using the
formuta:
reference signal time duration
Horizontal (seconds)
Conversion = -
Factor Horizontal TIME/DIV
defiection X switch
(divisions) setting
Determine the arbitrary deflection factor using this
formula:
Arbitrary horizontal TIME/DIV
Deflection = conversion X switch
Factor factor setting
To measure the time duration of an unknown signal, set
the TIME/DIV switch to a setting that provides sufficient
horizontal defiection to make an accurate measurement.
Do not readjust the VAR TIME/DIV control. Measure the
horizontal defiection in divisions and calculate the time
duration using the formula:
Ti arbitratv horizontal
D s. = deflection X deflection
gaa factor (divisions)
or
Time horizontal TIME/DIV horizontal
Duration = conversion X switch X deflection
factor setting (divisions)
EXAMPLE: The reference signal frequency measured is
455 hertz (time duration: 2.19 milliseconds) with a
TIME/DIV switch setting of .2 ms, and the VAR TIME/DIV
control adjusted to provide a horizontal deflection of eight
@ 475A/DM44 Operators 41