IET Labs, Inc. HPRS-F-3-0.01, Руководство пользователя и обслуживания

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9
INTRODUCTION
HPRS Series
Chapter 1
INTRODUCTION
The High-Power Decade Resistance Substituter
(
HPRS) Series is a family of instruments offering a
broad choice of high-power, excellent-performance
resistance sources (Figure 1.1). High-power resistors
are made available without sacrifi cing other electrical
properties. Any number of decades is available in a
choice of two accuracies.
The HPRS Series employs state-of-the-art precision
resistors of various types for high accuracy, high
stability, and low temperature and power coeffi cients-
of-resistance.
The standard models offer a choice of three to nine
decades. The panels are clearly labeled showing the
step size and maximum voltage and current limita-
tions for each decade.
With a resolution as low as 1 m
Ω
and a maximum
resistance of 10 M
Ω
, the HPRS Series may be used
as a general purpose substituter as well as a high-
power load for testing power supplies and for other
high-power applications.
Applications include calibration of meters and instru-
ments.
HPRS instruments are useful development
tools wherever precise resistances with high-power
handling capacity are required.
It is important to keep the amount of time power is
applied the the HPRS within the duty cycles below.
The duty cycles assume an ambient temperature of
around 23
0
C.
Power Time on Time off
<101 W continuous none
>101 W 5 minutes 10 minutes
Exceeding the time on can cause damage to the
resistors.
If continuous use is required to full rated power see
DRS-900 High Power Resistance Substituter.
Figure 1.1 DRS-900 High-Power Decade
Resistance Substituter
The HPRS series complements the HRRS and HARS
series, providing resistance steps as low as 1 m
Ω .
The
units may be rack-mounted to serve as components
in measurement and control systems.
This series is part of a family of resistance substitut-
ers suited to fi ll many engineering and testing needs.
Consult IET for:
High power substituters - up to 400 W
High resistance substituters - to 1 T
Ω
RTD simulators
Laboratory-standard-grade substituters - to 20 ppm
accuracy
Programmable substituters - IEEE-488, USB or
Ethernet.
Figure 1.2 HPRS Series High-Power Decade
Resistance Substituter