Stanford Research Systems DS335, User Manual

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4-8 Performance Tests
DS335 Synthesized Function Generator
PERFORMANCE TESTS
These tests are intended to measure the DS335's conformance to its published specifications. The test
results may be recorded on the test sheet at the end of this section. Allow the DS335 at least 1/2 hour to
warm up, run the DS335's self test procedure, and proceed with the tests.
FREQUENCY ACCURACY This test measures the accuracy of the DS335's frequency. If the frequency
is out of specification the DS335's timebase frequency should be adjusted
(see CALIBRATION section).
Tolerance: ± 50 ppm of selected frequency
1) Turn the DS335 on and allow it to warm up for at least 1/2 hour. Set the
DS335 for sine wave, 1 MHz, 1 Vpp, and 50
Ω
Load Impedance.
2) Attach the output of the DS335 to the frequency counter. Terminate into
50
Ω
. Attach the reference frequency input of the counter to the
frequency standard. Set the counter for a 1s frequency measurement.
3) The counter should read 1MHz ± 50Hz. Record the result.
AMPLITUDE ACCURACY The following tests measure the accuracy of the DS335 output amplitude.
There are separate tests for sine, square, and ramp/triangle. The tests
measure the accuracy of the amplitude as a function of frequency. The sine
wave test also measures the performance of the attenuators. There is only a
single test for triangle and ramp functions because they have the same
signal path.
Frequency < 100 kHz Connect the DS335 output to the voltmeter through the 50
Ω
terminator. After
the DS335 has had at least 1/2 hour to warm up, perform the following tests.
Sine Wave
specification: ±0.1 dB (±1.2%)
1) Set the DS335 to sine wave, 100Hz, 3.54 Vrms (10Vpp), and 50
Ω
Load
Impedance.
2) Read the AC voltage on the voltmeter. Repeat at 1kHz and 10kHz, and
100 kHz. The readings should be between 3.498 and 3.582 Vrms
(±1.2%) Record the results.
3) Set the DS335 to 1 kHz. Set the amplitude to 1 Vrms. Read the
voltmeter and record the results. The amplitude should be between
0.988 and 1.012 Vrms. Repeat at 0.5 Vrms, 0.25 Vrms, 120 mVrms, 70
mVrms, 40 mVrms, and 20 mVrms. Record the results. They should be
within ±1.2% of the set values.
Square Wave
specification: ±1.2%
1) Set the DS335 to square wave, 100Hz, 5Vrms (10 Vpp), and 50
Ω
Load
Impedance.