Symmetricom 5071A, Сборка и сервисное обслуживание

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1. Performance Tests – Verifying Specifications
5071A Complete Performance Tests
20
Figure 1-8. Error Measurement
In the example, the frequency difference,
Δ
f/F, is computed as follows:
Δ
f/F =
Δ
t/T
Δ
t
= (7 minor divisions × 2x10
-9
seconds/minor divisions)
= 14x10
−
9
seconds
T
= 8 hours or 2.88 × 10
4
seconds
Δ
f/F =
Δ
t/T = 14 × 10
-9
/2.88 × 10
4
= 4.9 × 10
-13
or 4.9 parts in 10
13
This shows that frequency difference between the unit under test and the
reference is 4.9 parts in ten to the 13th. This is only an example. The
measured frequency accuracy of a 5071A should be 1 x 10
−
12
or better for a
Long-Life (Standard), or 2 x 10
−
13
or better for a high performance unit
NOTE
The final computation should include the accuracy of the reference
source.
12 Record the actual reading in the appropriate place in the
Performance Test Record.