Keysight U8903B - Frequency Accuracy Verification; Table 3-3 Frequency Accuracy Specifications

3 Performance Verification for Analog Analyzer
42 Keysight U8903B Service Guide
8 Using the voltage measured at 1 kHz as reference, compute the flatness using the
following equation. The frequency response is relative to the amplitude at 1 kHz.
Flatness (dB) = 20
× log
10
(V
DUT
at that particular f
IN
/ V
DUT
at 1 kHz)
9 Repeat step 4 to step 8 for the rest of the frequency f
IN.
10 Repeat step 3 to step 9 for the rest of V
IN
to complete the verification of the U8903B
input channels to be tested.
11 Compare the recorded AC accuracy and flatness values to the specifications. If the test
fails, adjustment will need to be carried out accordingly.
Frequency accuracy verification
This test verifies the frequency accuracy of the U8903B analyzer by using the function
generator as a source and the frequency counter as a reference, to ensure that it is within
the published specification.
1 Use three BNC male-to-female T splitters to create a 4-way connection from the
function generator output to the U8903B and frequency counter inputs.
2 Connect the function generator outputs to the frequency counter input channel 1 and
2, and to the U8903B unbalanced input channel 1 and 2 as shown in Figure 3-3. Preset
the U8903B, function generator, and frequency counter.
Table 3-3 Frequency accuracy specifications
Frequency accuracy specification Equipment used
±(2 ppm + 100 μHz) ≤50 kHz
±5 ppm >50 kHz
– Function generator
– Frequency counter
NOTE
Power on the U8903B audio analyzer for at least 30 minutes before performing the
performance verification.