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Entry  Wed Oct 11 10:29:43 2017, Steve, Update, Electronics, SR560 noise level sr560.jpgsr560noise.jpg
    Reply  Wed Oct 11 17:59:45 2017, rana, Update, Electronics, SR560 noise level 
Message ID: 13373     Entry time: Wed Oct 11 17:59:45 2017     In reply to: 13371
Author: rana 
Type: Update 
Category: Electronics 
Subject: SR560 noise level 

these are not the SR785 settings that you're looking for

Quote:

Gautam and Steve,

All 3 show the same noise level ~80 nV / rt Hz at 1 kHz as shown. Batteries ordered to be replaced in the top 2

We'll do more measurement to see how can we get to 4 nV / rt Hz  specification level.

To get low noise measurements on the SR785, you have to have the input range set to -50 dB, not +20 dB. Its not within the powers of commercial electronics ADCs to give you a 10 nV noise floor with +10 V input signals. The SR560 has an input referred noise of 5 nV/rHz, so the output noise should be 5e-9 x 500 = 2.5 uV/rHz. Your picture shows it giving 1 uV RMS, so you also need to use the PSD units.

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