Datasheet

Model 3800
Vishay Micro-Measurements
Document Number: 11247 [e-mail] www.vishaymg.com
Revision 08-Jun-06 9
Wide Range Strain Indicator
FEATURES
• 4-1/2 Digit LED Display
• ANSI/SEM Color-coded bridge connection terminals
• Analog output
• Transducer connector with remote sense
• Direct reading of strain, pressure, torque, load, and other
engineering variables
• Convenient color-coded push-button controls
• Gage factor range from 0.0500 to 50.00 displayed on LED
readout (to four significant digits)
• Bridge excitation range from 1.000 to 15.000Vdc
• Extremely wide balance range. Balance by voltage
injection
• Quarter-, half-, and full-bridge circuits
• Built-in 120/1000Ω and 350Ω bridge completion
• Separate bridge excitation on/off control
A versatile high-performance laboratory-type instrument
featuring wide-range operating controls for handling the most
critical strain measuring tasks.
DESCRIPTION
EXCEPTIONAL RANGE • RESOLUTION • VERSATILITY
NEVER BEFORE ACHIEVED IN A LABORATORY
INSTRUMENT
The Model 3800 Wide Range Strain Indicator is a versatile,
high-precision laboratory-type instrument designed for use
with strain gages and strain gage based transducers.
Principal features of the Model 3800 are wide-range control
of gage factor; excitation precisely settable over 1 - 15 volt
range; and wide balance range with no bridge loading effect.
With these extended operating capabilities, the Model 3800
can be used for the most demanding measurement tasks
which are not possible with conventional strain measuring
instruments and general-purpose transducer indicators.
Resolutions achievable with the Model 3800 are 0.10µε
when used as a strain indicator, and 0.10µV/V when used as
a transducer indicator (0.025µV/V with suppressed zero).
In addition to the wide-range features, the Model 3800
incorporates simplified operating controls that minimize
set-up time, and promote measurement accuracy. The
operator follows a logical sequence of steps to configure the
instrument for the desired measurement. Color-coded
interlocked push-button controls minimize operator errors,
and make the operating mode instantly recognizable.
Gage factor on the Model 3800 is settable by front-panel
controls over a range of 0.0500 to 50.00, and is displayed by
the LED readout when in the SET position. The instrument
allows full range display (±19 999 counts) over the complete
gage factor range.
Excitation voltage is precisely settable over a range of 1 - 15
volts in 1-volt increments by a front-panel thumbwheel
switch. The output display automatically tracks the excitation
setting so that gage factor does not vary with bridge voltage.
The balance system in the Model 3800 has four ranges
which are selected by the BALANCE RANGE push buttons.
Each range is further divided into four sub ranges by the
COARSE balance switch. The FINE balance control provides
an additional adjustment range that overlaps the COARSE
balance switch positions. This unique system provides a total
of 32 overlapping ranges for achieving precise balance
settings and resolution. All balance voltages are
electronically injected into the input amplifier to eliminate
bridge loading errors and preserve full measurement range.
The instrument will accept full-, half-, or quarter-bridge strain
gage inputs; and all required bridge completion components
for 120, 350, and 1000Ω gages are built in. Shunt-calibration
resistors across the internal dummies are provided on the
rear panel. Two remote calibration resistors, also mounted
on the rear panel, are actuated by the front-panel calibration
button.
Virtually all strain gage based transducers can be used with
the Model 3800 via the rear-panel transducer connector. This
connector provides precision remote sense capability, as
well as access to the remote calibration resistors. Full-scale
resolutions of 0.10µV/V are routinely possible. By using the
wide-range balance controls to suppress zero, resolutions to
0.025µV/V can be achieved.
In addition to the digital LED display, the Model 3800
provides an analog output available at the rear panel. A
separate analog level control totally independent of the
digital display is also provided.
The Model 3800 Wide Range Strain Indicator is an
exceptional, high-resolution instrument that will make a
valuable contribution to any experimental stress analysis or
transducer development laboratory.