Phase Accuracy - Stanford Research Systems SR850 User Manual

7. Phase Accuracy

This test measures the phase accuracy of the lock-in. Due to the design of the lock-in, the phase accuracy
can be determined by measuring the phase of the internal oscillator Sine Out.
Setup
Connect the Sine Out to the A input of the lock-in using a 1 meter BNC cable. Do not use any termination.
Procedure
1) {PRESET} (Turn the lock-in off and on with the [ ] key pressed)
2) Press the keys in the following sequence:
[GAIN/TC]
<Filter db/oct>
[INPUT/FILTERS]
<Coupling>
[DISPLAY/SCALE]
<Type and Trace>
<Top and Bottom>
3) The value of R should be 1.000 V (±2%) and the value of should 0° (±1°).
4) Phase accuracy is checked at various frequencies. The test frequencies are listed below.
Test Frequencies
100 Hz
10 kHz
a) Press
[REF/PHASE]
<Ref. Frequency>
b) Wait for the readings to stabilize. Record the value of .
c) Repeat steps 4a and 4b for all frequencies in the table.
5) This completes the phase accuracy test. Enter the results of this test in the test record at the end of
this section.
Select 24 dB/oct.
Select DC coupling.
Highlight the trace number.
Use the knob to select trace 3 (R) for the top display.
Select the Bottom display.
Use the knob to select trace 4 ( ) for the bottom display.
10 Hz
1 kHz
Enter the frequency from the table.
Performance Tests
7-17