SRS Labs SR850 - Manual (Page 221)

7-3
Performance Tests
Necessary Equipment
The following equipment is necessary to complete
the performance tests. The suggested equipment
or its equivalent should be used.
1. Frequency Synthesizer
Freq Range 1 Hz to 1 MHz
Freq Accuracy better than 5 ppm
Amplitude Accuracy 0.2 dB from 1 Hz to
100 kHz
Harmonic Distortion
≤
-65 dBc
Spurious
≤
-55 dBc
TTL SYNC available
Recommended SRS DS345
2. AC Calibrator
Freq Range 10 Hz to 100 kHz
Amplitude 1 mV to 10 V
Accuracy 0.1%
External phase locking capability
Recommended Fluke 5200A
3. DC Voltmeter
Range 19.999 V, 4 1/2 digits
Accuracy 0.005%
Recommended Fluke 8840A
4. Feedthrough Terminations
Impedance 50
Ω
Warm Up
The lock-in should be turned on and allowed to
warm up for at least an hour before any tests are
performed. The self test does not require any
warm up period.
It is necessary to turn the unit off and on to preset
it. As long as the unit is powered on immediately,
this will not affect the test results.
The Test Record
Make a copy of the SR850 Performance Test
Record at the end of this section. Fill in the results
of the tests on this record. This record will allow
you to determine whether the tests pass or fail and
also to preserve a record of the tests.
If A Test Fails
If a test fails, you should check the settings and
connections of any external equipment and, if pos-
sible, verify its operation using a DVM, scope or
some other piece of test equipment.
After checking the setup, repeat the test from the
beginning to make sure that the test was per-
formed correctly.
If the test continues to fail, contact Stanford
Research Systems for further instructions. Make
sure that you have the unit's serial number and
firmware revision code handy. Have the test
record on hand as well.