iET PRS-330 series, Operation Manual, Page: 13 / 67

INTRODUCTION
PRS-330 Series
1
Chapter 1
INTRODUCTION
The PRS-330 (Figure 1.1) is a high
precision manual and programmable decade
substituter. The PRS-330 series provide
direct resistance substitution as well as RTD
(Resistance Temperature Detector) simulation.
The PRS-330 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.
Operation is both local using convenient
touch screen, keypad and standard USB,
Ethernet, and IEEE-488.2 interfaces.
The PRS-330 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-330 may be used for exacting precision
measurement applications requiring high
accuracy, good stability, and low zero resistance.
The PRS-330 is suited for automatic and
manual calibration and testing, simulation
of RTD’s, programmable loads, and many
other laboratory and industrial applications.
The PRS Series may be rack mounted to serve as
components in measurement and control systems.
The PRS-330 (Figure 1.1) is part of the
PRS family of high precision manual and
programmable decade substituters. This
series offers a wide choice of ranges, power,
voltage, and accuracies for a wide variety
of design and production applications.
The PRS-330 uses a microcontroller design to
enhance the ease of use and calibration. It provides
Figure 1.1: High Precision Programmable Decade
Resistance Substituter