I have recently aquired a nice 5.1/2 digit DVM, and would like to assess
the absolute accuracy. Many years ago I had a 'Standard Cell', but that
got lost in one of my several relocations.
What is a good alternative these days? I would think that there is a
semiconductor device that has a known threshold. I am familiar with the
Wheatstone bridge method to measure voltage without affecting the reference.
Once I have a good DC reference, getting AC & RMS calibration is fairly
easy.
Having a GPS locked time and frequency reference, I am used to being at
the 1e-10 accuracy level for those, but if I can get to 1e-5 for analog
voltage I would be very happy.
Any suggestions gratefully received.

73 Alf NU8I
Scottsdale AZ DM43an
160m - 10 Gigs