Power Reference Oscillator Level Adjustment; Description - Agilent Technologies E4416A Service Manual

Power Reference Oscillator Level Adjustment

Description

This test adjusts the power level accuracy of the internal 50 MHz
oscillator- also called the power reference oscillator.
The power reference oscillator output is factory adjusted to 1 mW ±0.4%. This
accuracy includes a performance limit of 0.1% and a system measurement
uncertainty figure of 0.3% (traceable to the National Physical Laboratory
(NPL), UK).
The setting of the oscillator output accuracy is determined from the system
N O TE
measurement uncertainty plus any chosen test line limit. For example, if a test line limit
of 1 mW ±0.2% was chosen while maintaining a system measurement uncertainty of
±0.3%, the overall accuracy of the test setup for the 1 mW power output becomes 0.3%
+ 0.2%, giving a setting accuracy of 0.5%.
If an equivalent measurement system is employed for post- factory test, the
power reference oscillator output can again be set to 1 mW ±0.4%. This setting
is sufficient to ensure that the power reference oscillator meets the accuracy
specification of ±0.5% after 2 years. This specification includes the ±0.4%
setting and also takes into account other factors that will contribute to
determining the accuracy after 2 years. The complete breakdown of the ±0.5%
specification is as follows:
• Test line limit: 0.1%.
• System uncertainty: 0.3%.
• 2 year oscillator drift: 0.04%.
• Delta environment: <0.06%.
The following adjustment procedure ensure the power reference oscillator
meets the post- factory accuracy setting of ±0.4%.
E4416A/E4417A Power Meters Service Guide
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