[volt-nuts] Traveling Standards - pictures + protocol

[Andreas Jahn]

> WarrenS wrote:
>> Bob
>>
>> Another thought.
>> Soldering plastic voltage reference parts to a PCB can also cause stress
>> problems.
>> Part of your high resolution testing should be to Flex the PCB board a
>> little in both axes.
>> Then push and tap on the top the parts a little to see what happens.
>> I've seen some parts work better as a strain gain than a voltage
>> reference when mounted to a PCB.
>
> Good suggestion.  I will include that when I get the differential test
> setup.

Yes really good point. Just yesterday I did the first tests on my
new built reference VRE3050AS (#1). It is claimed to be the
most stable non heated reference according to the manufacturer.
Because of the hermetic ceramic package I thougth that I can
solder it directly to the PCB. But I had around 180 uV difference
from max to min by tweaking the PCB. Which is less than the
values found from other references, but which is much more
than my 5uV value when soldering only the ground pin directly
to the PCB.

With best regards

Andreas