Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Realization of the farad from the dc quantum Hall effect with
  digitally-assisted impedance bridges   A new traceability chain for the derivation of the farad from dc quantum Hall
effect has been implemented at INRIM. Main components of the chain are two new
coaxial transformer bridges: a resistance ratio bridge, and a quadrature
bridge, both operating at 1541 Hz. The bridges are energized and controlled
with a polyphase direct-digital-synthesizer, which permits to achieve both main
and auxiliary equilibria in an automated way; the bridges and do not include
any variable inductive divider or variable impedance box. The relative
uncertainty in the realization of the farad, at the level of 1000 pF, is
estimated to be 64E-9. A first verification of the realization is given by a
comparison with the maintained national capacitance standard, where an
agreement between measurements within their relative combined uncertainty of
420E-9 is obtained.

24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg