IET Labs 1404 Series, Руководство по эксплуатации

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1
1404 Series
1 Introduction
Chapter 1
INTRODUCTION
1.1 Description of the 1404 Series
The 1404 Series (Figure 1-1) are stable, pri-
mary laboratory pacitance standards. They are
working and laboratory standards grade. The
1404 units are available in values ranging from
10 pF to 10 nF with custom values available.
All critical parts of the plate assembly are made of
invar for stability and low temperature coeffi cient.
After heat cycling and adjustment the assembly is
mounted in a heavy brass container, which after
evacuation, is fi lled with dry nitrogen under pressure
slightly above atmospheric and sealed. The container
is mounted on an aluminum panel and protected by
an outer aluminum case. Each capacitor is subjected
to a series of temperature cycles to determine hys-
teresis and temperature coeffi
cients and to stabilize
the capacitance.
Connections are made to the 1404 via two bnc connec-
tors to minimize lead stray capacitance. Traditional
GenRad 874 connectors are also available upon
request.
Figure 1-1: 1404-A Primary Capacitance
Standard
Figure 1-2: 1404-10nF shown next to
standard 1404-A