Prostat PRF-912B, Руководство пользователя

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4 Rev. A / November 2005
PRF-912B Miniature Concentric Ring Fixture Set
I. Introduction & Description
The PRF-912B Miniature Concentric Resistance
Fixture accurately measures surface resistance
of small areas. It consists of a PRF-912B Concen -
tric Resistance Fixture, shielded cable equipped
with BNC connectors, and a BNC to male banana
con¬nectors adapter. The optional PRV-913B Dual
Verification Fixture is designed to confirm the
proper operation of the PRF-912B and PRF-922B
Miniature Concentric Resistance Fixtures.
The PRF-912B is designed to work in conjunction
with a precision wide range resistance instrument,
such as the Prostat PRS-801 Resistance System, and
an insulated test bed (e.g., PTB-920 or equivalent).
This instrument and fixture combination provides
direct surface resistance measurements in ohms,
generally in accordance with the ESD Association’s
S11.11 Surface Resistance test standard. To obtain
an estimate of ASTM D-257 Surface Resistivity in
ohms/square, simply multiply the PRF-912 fixture
measurement by 10, i.e., add one order of magnitude.
A. PRF-912B Concentric Resistance Fixture Description
This precision fixture is designed in miniature to approximate surface resistance measurements
typically obtained with the ESD Association’s ESD S11.11 Surface Resistance Standard fixture. The
PRF-912B, however, is approximately 1/10th the size of the S11.11 fixture. Based on its size the
PRF-912B is often referred to as a “micro probe”.
1. The resistance measurement range of the PRF-912B fixture is 0.9 ohms at <10 volts to 1.0E+12
(1.0x10
12
) ohms at 100 volts.
2. The miniature concentric fixture consists of a spring loaded 0.10 inch (2.54 mm) diameter
center electrode surrounded by 10 each 0.06 inch (1.5 mm) diameter contact electrodes that
electrically form a continuous outer ring. (Figure 2) Contacts are pogo-pin type ATE quality
probes made of beryllium Copper coated with 60 microinch of hard Gold.
a. The PRF-912B’s center electrode is electrically separated from the outer ring contacts by
a high resistance dielectric (Teflon). The center electrode acts as a current sensor during
resistance measurements. It is connected to the negative (-) terminal of a wide range mea -
surement instrument via the RG-174 coaxial cable’s inner conductor, BNC coupler and dual
BNC/Banana adapter.
b. The outer ring contacts are electrically connected at a common point. They apply the test
voltage to the material under test during a resistance measurement. They are connected to
the positive (+) terminal of the wide range measurement instrument via the RG-174 coaxial
cable’s outer conductor, BNC coupler and dual BNC/Banana adapter.
c. The fixture’s total surface contact diameter is approximately 0.30 inches, and is ideal for
measuring surface resistance of small areas, 0.32 inches or larger.
Figure 1: PRF-912B Miniature Concentric Resistance
Fixture Measurement Set with Optional PRV-913B
Dual Verification Fixture.