Testing Performance
2
7000 Series Oscilloscopes Service Guide
45
4
Make the measurement.
a
Set oscilloscope horizontal sweep speed control to
1 ms/div.
b
Set horizontal position control to +1 ms (rotate control
CCW).
c
Set the oscilloscope horizontal sweep speed control to
5 ns/div.
d
Record the number of nanoseconds from where the
rising edge crosses the center horizontal grid line to
the center vertical grid line. The number of
nanoseconds is equivalent to the time scale error in
ppm.
e
Use the date code on the oscilloscope’s serial tag to
calculate the number of years since manufacture.
Include any fractional portion of a year.
f
Use the following formula to calculate the test limits.
TSA Limit: ± (15 + 2 * YrsSinceMfr) ppm
g
Record the result and compare it to the limits in the
Performance Test Record (see
page 57
).
Date Code:
0747
07 = Year
47 = Week
