General Description; Controls, Indicators, And Connectors - QuadTech 1657 RLC Digibridge Instruction Manual

1.1 PURPOSE

1.2 GENERAL DESCRIPTION

1.3 CONTROLS, INDICATORS, AND CONNECTORS

1.4 ACCESSORIES
1.1 PURPOSE.
The 1657 Digibridge digital impedance meter embodies
use of a microprocessor and other LSI circuitry to
provide excellent performance at low cost.
A few clearly labeled pushbuttons and the versatile
built-in test fixture make this instrument a model for con-
venience. Measurement results are clearly shown with dec-
imal points and units, which are automatically presented to
assure correctness. Display resolution is 5 digits for R, C,
and L (4 for D or Q) and the basic accuracy is 0.2%.
Long-term accuracy and reliability are assured by the
measurement system. It makes these accurate analog
measurements over many decades of impedance without a
single calibration or "trimming" adjustment (not even in
original manufacture).
The built-in test fixture, with a pair of plug-in adaptors,
receives any common component part (axial-lead or radial-
lead) so easily that insertion of the DUT is a one-hand
.
.
operation. True 4-terminal connections are made automat
t
I
.
ically. Extender cables and other accessories are available
for measurements at a distance from the Digibridge.
1.2 GENERAL DESCRIPTION.
Convenience is enhanced by the arrangement of test
fixture on the front ledge, with push buttons farther for-
ward and display behind. The display panel is inclined and
recessed to enhance visbility of digital readouts and mode
indicators. These indicators serve to inform and guide the
operator as he operates the simple controls.
The instrument stands on a table or bench top. The
sturdy metal cabinet is attractively and durably finished,
.
in keeping with the long-life circuitry inside. Glass-epoxy
circuit boards interconnect and support high-quality com
ponents to assure years of dependability.
Adaptability to any common ac power line is assured by
the removable power cord and the convenient line-voltage
switch. Safety is enhanced by the fused, isolating power
transformer and the 3-wire power connection. A compre
hensive functional description is given in Theory, Section 4
Electrical and physical characteristics are listed in Specifi
cations at the front of this manual, dimensions in Installa
tion, Section 2. Controls are described below, and their use
in Operation, Section 3.
1.3 CONTROLS, INDICATORS, AND CONNECTORS.
.
Figure :-1 shows the front panel conrols and indicators.
Table 1-1 identifies them with descriptions and functions.
Similarily, Figure 1-2 shows the rear panel and Table 1-2 identifies
Identifies and describes the rear panel controls and connec
and describes the rear panel controls and connectors.
1.4 ACCESSORIES.
Gen Rad makes several accessories that enhance the use
fulness of this instrument. Two extender cables facilitate
making connections to those devices and impedance stan
dards that do not readily fit the built-in test fixture. A
remote test fixture (used with BNC adaptor and cable
assembly) provides convenience and relatively easy main
tenance, and saves wear on the built-in test fixture. All of
these test-fixture accessories provide for true 4-terminal
connections (and guard) to the device being measured,
without appreciable reduction in measurement accuracy.
Other useful accessories are offered, such as standards for
checking the performance of the Digibridge. Refer to
Table 1 -3 and Section 5.
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INTRODUCTION 1-1