[volt-nuts] The "averaging reference"

[M K]

On 19/12/2014 22:13, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:
> On 19 Dec 2014 19:30, "Jan Fredriksson" <jan at 41hz.com> wrote:
>> It's no coincidence that virtually all 8.5 digit DMMs use the LTZ1000.
>> It's in a class of it's own.
> What do the 8.5 digit meters use if they don't use the LTZ1000?
>
> Dave.
>
Well the 7081 uses well conditioned 1n829 zeners with a parabolic 
temperature compensation scheme, but Mickle does not have a good opinion 
on how well it works. but it could possibly be that the drift over the 
decades since manufacture means it is running at the wrong current now.