7. Input Noise
This test measures the SR844 input noise.
Setup
Ω
Connect a 50
termination to the signal input.
Procedure
1) Press Shift then Recall to restore the factory preset instrument settings.
2) Press the keys in the following sequence:
Sensitivity Down until
the sensitivity is 300 nV.
CH1 Display three times
Set the CH1 display to Xnoise.
Close Reserve once until
LOW NOISE is selected.
3) Wait until the CH1 display stabilizes. Record the value of the CH1 display (nV/
4) This completes the noise test. Enter the results of this test in the test record at the end of this
chapter.
Performance Tests 5-17
√
Hz).
SR844 RF Lock-In Amplifier