micro-measurements@vishay.com
Strip Gage Patterns
Vishay Micro-Measurements
Document Number: 11514
Revision 10-Jan-03
www.vishaymg.com
87
Special Purpose Sensors - Strip Gage Patterns
GAGE PATTERN
Actual size shown.
Enlarged when necessary for definition.
ES = Each section CP = Complete pattern
S = Section (S1= Sec 1) M = Matrix
inch
millimeter
GAGE RES. IN OHMS
DESIGNATION Tolerance is
Insert desired S-T-C increased when OPTIONS AVAILABLE
number in spaces Option W, E, SE, LE,
marked XX. or P is specified.
GAGE OVERALL GRID OVERALL
LENGTH LENGTH WIDTH WIDTH
MATRIX SIZE
GAGE OVERALL GRID OVERALL
LENGTH LENGTH WIDTH WIDTH
MATRIX SIZE
020PF
0.020 ES 0.100 CP 0.030 ES 0.385 CP
0.51 ES 2.54 CP 0.76 ES 9.78 CP
0.19L x 0.48W 4.8L x 12.2W
Miniature ten-element strip gage for strain gradient determination. One tab
common to all sections. Grid centerline spacing 0.035 in (0.89 mm). Similar
to 020MT pattern but with grids rotated 90°. Resistance is measured
between a single point on the common tab, and each individual grid tab.
EA-XX-020PF-120
SA-XX-020PF-120 120 ±1.0%
120 ±2.0%
E, SE, L, LE
0.020 ES 0.385 CP 0.025 ES 0.100 CP
0.51 ES 9.78 CP 0.64 ES 2.54 CP
0.48L x 0.19W 12.2L x 4.8W
Miniature ten-element strip gage for strain gradient determination. One tab
common to all sections. Grid centerline spacing 0.035 in (0.89 mm). Similar
to 020PF pattern but with grids rotated 90°. Resistance is measured
between a single point on the common tab, and each individual grid tab.
EA-XX-020MT-120
SA-XX-020MT-120
120 ±1.0%
120 ±2.0% E, SE, L, LE
020MT
1X
2X
1X 2X
A strip gage consists of ten strain-sensitive grids mounted
on a common backing. This type of gage offers a number of
advantages in the study of local strain distributions and
strain gradients. As an example, it is much easier, faster,
and more accurate to install the ten-grid strip in a single
operation than it would be to align and bond ten individual
gages for the same purpose. In addition, the optical tooling
employed in the manufacture of the strip gage ensures that
all grids are precisely located. Grid spacing is also closer
than can usually be achieved with individual gages, thus
yielding better resolution of nonuniform strain fields.
Overall dimensions for the complete patterns vary with the
grid and solder-tab configurations. When necessary, some
types of the gages can be cut to produce smaller
assemblies with fewer grids. Most sizes are offered in two
different versions — with all grids oriented either parallel to,
or perpendicular to, the long axis of the strip. As indicated in
the gage listings, several types of strip gages are designed
with a common tab, or bus, connected to all grids on one
side. Since this arrangement affects measurement
accuracy, and may not be compatible with some instrument
systems, the following information should be considered
when contemplating the use of such gages.
COMMON-TAB STRIP GAGES
Common-tab strip gages are generally not compatible with
multi-channel instruments, particularly those incorporating
individual bridge excitation supplies. When used with this
type of instrumentation, they will yield significantly lower
accuracy than a strip gage with electrically independent
grids. Effects of the common tab include excessive initial
unbalance of the Wheatstone bridge circuit (possibly
beyond the balance range of the instrumentation),
circulating currents when the grids are powered
simultaneously from a common power supply, loss of
leadwire temperature compensation, and reduced accuracy
in shunt calibration. All of these effects should be carefully
considered by the user before selecting strip gages with
common tabs. Where greatest accuracy is required, strip
gages with electrically independent grids should be
employed, or common-tab strip gages may be used with
single-channel instruments in conjunction with a switch and
balance unit.
For further information, and practical recommendations on
the use of common-tab strip gages, request Vishay Micro-
Measurements Tech Note TN-516, Errors Due to Shared
Leadwires in Parallel Strain Gage Circuits.