Keysight Technologies DSOX1102A, Service Manual

Page: 31 / 60

Testing Performance
2
1000 X-Series Oscilloscopes Service Guide 31
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 base error in ppm.
e Derive the date code from the oscilloscope’s serial number to calculate the
number of years since manufacture. Include any fractional portion of a year.
i First, get the 3rd to 6th digits of the serial number. For example, for the
serial number CN47470001, get “4747”.
ii If the number is greater than 4000, subtract 4000 to get the Date Code.
For example, 4747-4000 is “0747”.
iii If the number is smaller than 4000, add 6000 to get the Date Code.
iv In the Date Code, the first two digits represent the year, and the second
two digits represent the week in the year. For example, for “0747”, the
year is “07” and the week is “47”.
f Use the following formula to calculate the test limits.
Time base accuracy limit: 50 ppm ±5 ppm per year (aging)
g Record the result and compare it to the limits in the Performance Test
Record (see page 39 ).