Chapter 2 47
Performance Verification Tests
2. 10 MHz High-Stability Frequency Reference Output Accuracy: Agilent E4401B, E4402B,
E4404B, E4405B, and E4407B (Option 1D5)
8. Continue with next step 15 minutes after the Power On Time noted
in step 2.
9. Wait for the universal counter reading to make at least two readings.
Record the universal counter reading in Table 2-3 as Counter
Reading 2 with 0.001 Hz resolution.
10.Continue with next step 60 minutes after the Power On Time noted
in step 2.
11.Wait for the universal counter reading to make at least two readings.
Record the universal counter reading in Table 2-3 as Counter
Reading 3 with 0.001 Hz resolution.
12.Calculate the 5 Minute Warm-up Error (in ppm) by subtracting
Counter Reading 3 from Counter Reading 1 and dividing the result
by 10.
NOTE Dividing the frequency by 10 is equivalent to dividing the difference
first by 10 MHz (to normalize the difference to the reference frequency)
and then multiplying by 1 x 106 to convert the result to
parts-per-million (ppm).
13.Record the 5 Minute Warm-up Error (in ppm) in the performance
verification test record as Test Record entry 1.
14.Calculate the 15 Minute Warm-up Error (in ppm) by subtracting
Counter Reading 3 from Counter Reading 2 and dividing the result
by 10.
15.Record the 15 Minute Warm-up Error in the performance
verification test record as Test Record entry 2.
5 Minute Warm-up Error Counter Reading 1 Counter Reading 3–()10⁄=
Table 2-4 10 MHz Reference Accuracy Worksheet
Description Measurement
Counter Reading 1 ___________ Hz
Counter Reading 2 ___________ Hz
Counter Reading 3 ___________ Hz