| The strain gauge operates on the
principle that a tensioned wire, when
plucked, vibrates at a frequency that
is proportional to the strain in the
wire.
The gauge is constructed so that a
wire is held in tension between two
mounting blocks that are welded to
the structural member. Loading of the
structural member changes the distance
between the two mounting
blocks and results in a change in the
tension of the wire.
An electromagnet is used to pluck
the wire and measure the frequency
of vibration. Strain is then calculated
by applying calibration factors to the
frequency measurement. |
| The strain gauge is screwed onto
mounting plates, which are welded,
screwed, or bonded to the structure.
Because there are a wide variety of
surfaces to which the gauge can be
attached, two types of mounting
plates are available, one for steel and
one for concrete. |
Permanently Attached Coils: The
coils used to excite and read the
vibrating wire are permanently
attached to the gauge. This prevents
accidental separation of the coil from
the body during installation and wiring
operations.
Easy Installation: Mounting plate
system ensures that gauges are not
damaged during attachment to the
structure. The gauges can also be
removed, if necessary, and moved to
a different location.
Field Adjustable: The strain gauge
can be adjusted so that most of its
range is available to measure compression
or tension, as required by
the application.
Reliable Signal Transmission: The
arc-weldable strain gauge provides a
strong signal which can be transmitted
reliably over long distances with
properly shielded cable. |
| VW Surface Mount Strain Gauge |
SI52650306 |
| Strain gauge is designed for monitoring strain in
steel structures or strain in concrete or masonry
surfaces. Includes built-in thermistor or RTD.
Requires signal cable and mounting plates. |
| Range |
3,000 microstrain. User can set tension
to maximize range for the application. |
| Resolution |
1 microstrain with VW Data
Recorder |
| Accuracy |
± 0.1% FS |
| Thermal Coefficient |
11ppm / °C |
| Gauge Length |
140 mm (5.5"). |
| Mounting Plates for Steel |
SI52650320 |
| Mounting Plates for Concrete |
SI52650330 |
| Set of two plates. The version for steel can be
arc-welded to a steel surface. The version for
concrete or masonry is bonded to the surface
and anchored by screws. Proper positioning of
mounting plates requires use of installation tool. |
| Installation Tool |
SI52650380 |
| Heavy-gauge, precision machined tool is used to
align and space mounting plates at installation
time. With the plates properly aligned, it is possible
to set the initial tension of every gauge identically.
The tool can be used with both steel or
concrete mounting plates. |
| Signal Cable |
SI50613324 |
| Shielded cable with four 24-gauge tinned-copper
conductors and flexible polyurethane jacket
rated to 80°C(176°F). |
| Universal Terminal Box |
SI57711600 |
| Provides connections for 12 sensors. Indicator
plugs into universal connector on panel. Sensors
selected by rotary switch. Weatherproof fiberglass
box is 290 x 345 x 135 mm deep (11.5 x
13.5 x 5.25"). |
e.jpg)