Keysight 1000B Series, Service Manual

Page: 29 / 46

Service
1
Keysight 1000B Series Oscilloscopes Service Guide 29
To test time scale accuracy
In this test you measure the absolute error of the timebase oscillator and compare
the results to the specification.
Time scale accuracy refers to the absolute accuracy of the oscilloscope's time
scale. Because time scale accuracy depends directly on the specifications of a
crystal oscillator, it is comprised of these components:
• An initial accuracy component — applies to the oscilloscope's accuracy on the
date of its shipment to the customer.
• A temperature component — refers to the ambient temperaure in which the
oscilloscope operates.
• An aging component — scales linearly from the oscilloscope's manufacture date
and adds to the initial accuracy and temperature components.
1 Set up the signal generator:
a Set the output to 10 MHz, approximately 1 Vpp sine wave.
2 Connect the output of the signal generator to oscilloscope channel 1 using the
BNC cable.
Table 8 Time Scale Accuracy Specification
Time Scale Accuracy ±50 ppm over 1 ms
Table 9 Equipment Required for Time Scale Accuracy Test
Description Critical Specifications Recommended
Model/Part Numbers
Signal Generator 100 kHz - 1 GHz, 0.01 Hz frequency resolution,
jitter: < 2 ps
Keysight N5181A,
Keysight E4400B, or
Keysight 8648A
BNC Cable 50 Ω characteristic impedance, BNC (m)
connectors
Keysight 8120-1840,
Keysight 10503A
Type-N to BNC Adapter Type-N (m) to BNC (f) Keysight 1250-0780
50
Ω
BNC Feed
Through Adapter
50
Ω
BNC (f) to BNC (m) feed through
terminator
Keysight 0960-0301