[volt-nuts] Solartron 7081 testing

[Михаил]

Joe,
I am very grateful to you! All of the data your acquired was completely
coincided with my results. Now I'm think I'm found a bottleneck in the Solartron
7081 perfomance. Slow analog multiplexor that are part of the Ratio
Circuit leads to improper function of the periodic drift correction (ADC Zero,
AutoZero) and to large DC voltage measurement errors, up to 5-7 ppm at the all
ranges.
This is the simple description of the problem I found: http://img31.imageshack.us/img31/9798/solartron7081autozerobu.jpg
This is the summary of the your measurement results: http://img856.imageshack.us/img856/636/adczero.png
This is the multiplexor and ADC schematic diagrams with my comments:
http://img822.imageshack.us/img822/2377/solartron7081adc.jpg
http://img40.imageshack.us/img40/371/solartron7081ratiocircu.jpg

Mickle T.

Sunday, December 4, 2011, 12:54:41 AM, you wrote:
JLT> Mickle,
JLT> Just sent you the file by PM.
JLT> Would love to know what it was I just did.  Hope it helps
JLT> Joe