Tektronix 47E5A

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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
compared with, or adjusted to, an exact number of
divisions .
Other unknown signals may be measured without
disturbing the setting of the VAR TIME/DIV control by
establishing 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
formula :
Horizontal
Conversion
Factor
reference signal time duration
(seconds)
Horizontal
deflection X
(divisions)
TIME/DIV
switch
setting
Determine the arbitrary deflection factor using this
formula:
Arbitrary
Deflection
Factor
horizontal
conversion X
factor
TIME/DIV
switch
setting
To measure the time duration of an unknown signal, set
the
TIME /DIV switch to a setting that prov i des sufficient
horizontal deflection to make an accurate measurement .
Do not readjust the VAR TIME /DIV control. Measure the
horizontal deflection in divisions and calculate the time
duration using the formula:
Time
Duration
arbitrary
deflection
factor
or
horizontal
horizontal
X deflection
(divisions)
Time
= conversion X
Duration
factor
TIME / DIV
switch
setting
horizontal
X deflection
(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/ OM44 Operators
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