IET Labs PRS-370 SERIES, Руководство по эксплуатации

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INTRODUCTION
PRS-370 Series
1
Chapter 1
INTRODUCTION
The PRS-370 (Figure 1.1) is a high
precision manual and programmable decade
substituter that can leverage an 8.5 digit
DMM to improve the accuracy to < 10 ppm.
The PRS-370 is a Self-Adjusting Programmable
Resistance Standard, just connect an 8.5
digit DMM; Fluke 8508A or the Keysight
3458A to the PRS-370 via the IEEE-488
interface, and the PRS-370 becomes a short-
term stable variable standard of resistance.
The PRS-370 instructs the DMM to make a
measurement of the source resistance and then
automatically
fi ne adjusts the output resistance
to achieve the “best” accuracy to the nominal
resistance value, typically better than 10 ppm.
The PRS-370 utilizes both the front and rear
binding posts so that the DUT and DMM
can be connected at the same time. Once the
resistance measurement is complete using
the DMM and rear binding posts, the source
resistance is switched to the front binding posts.
The PRS-370 substituter is a precision
resistance source with excellent characteristics
of stability, temperature coef
fi cient, and power
coefficient. These features combined with
a low virtually constant “zero resistance”
make for very versatile instruments.
O p e r a t i o n i s b o t h l o c a l u s i n g
convenient touch screen, keypad and
s t a n d a r d a n d I E E E - 4 8 8 . 2 i n t e r f a c e s .
The PRS-370 employs very low resistance,
low thermal emf relays with gold-clad silver-
alloy contacts. A special design keeps contact
resistance to a minimum. The gold plating keeps
the silver contacts from becoming tarnished
when unused, or when only low currents are
passed through them. This is most often the
case when only minute test currents are drawn
by digital multimeters and other test instruments.
Contact resistance remains low and repeatable.
High-quality gold-plated tellurium-copper
fi ve-way binding posts serve to minimize the
thermal emf effects, which would produce
errors in dc resistance measurements.
With a resolution as low as 1 μ
Ω
and a
maximum available resistance of 20 M
Ω
, the
PRS-370 may be used for exacting precision
measurement applications requiring high
Figure 1.1: High Precision Programmable Decade
Resistance Substituter