backed
half & full bridges
Backed bridges are installed on a flexible insulator membrane that can be bent around a 10 mm radius without hurting the gauge. They are available in different configurations, designed for different strain loading modes (e.g. torsion, bending, etc.).
Our Half-Bridge Backed Gauges are constructed using two thermally matched gauges bonded onto a backing, which allows them to track each other. When used as one side of the bridge, they compensate each other thermally even when bonded since they both see the same thermal expansion and temperature.
When both gauges have a gauge factor (GF) of 140, the transverse gauge will normally see the Poisson’s effect, which for most steels is 0.3 or less. This reduces the transverse gauge factor to 42. The average GF for the half bridge would be 91.
Backed half bridges use “bar” or “U” gauges.
Our Full-Bridge Backed Gauges are constructed using four thermally matched bar gauges bonded onto a backing.
Backed full bridges use “bar” gauges.
CONFIGURATIONS
Several standard backed half bridge and full bridge configurations exist and can be chosen depending on the stress at the surface of the part which is to be monitored (tensile/compression, bending, torsion). We can implement any solution depending on your requirements.
SSGH – bending stress
SSGH – bending stress “U”
SSGH – load 1D stress
SSGF – load: 1D stress, full bridge
SSGH – torque 1: torsion stress/shear
SSGH – torque 2: torsion stress/shear
BACKED HALF & FULL BRIDGES PRODUCT CODING
Semiconductor Strain Gauge Half Bridge (SSGH) – Total Length (X) – Active Length (Y) – Nominal Resistance – Shape (blank if bar) – Configured for bending application (B)
Example: SSGH-060-033-2000 PUB
SSGH; Total Length 0.06 inch; Active Length 0.033 inch; Nominal Resistance at 25° C 2000 P – Shape U – Configured for bending application (B)
BAR SHAPED
SSGH-080-050-120 PB
Total Length mm (inch): 2.032 (0.08)
Active Length mm (inch): 1.27 (0.05)
Width mm (inch): 0.203 (0.008)
Lead attachment: Welded
Thickness mm (inch): 0.010 (0.0004)
ELECTRICAL
Resistance, Ω @ 25°C: 120±20
Gauge Factor: 120±10
TCGF: -9%
TCR: 5%
SSGH-060-033-1000 PB
Total Length mm (inch): 1.524 (0.06)
Active Length mm (inch): 0.838 (0.033)
Width mm (inch): 0.203 (0.008)
Lead attachment: Welded
Thickness mm (inch): 0.010 (0.0004)
ELECTRICAL
Resistance, Ω @ 25°C: 1050±75
Gauge Factor: 155±10
TCGF: -18%
TCR: 24%
SSGH-080-050-345 PB
Total Length mm (inch): 2.032 (0.08)
Active Length mm (inch): 1.27 (0.05)
Width mm (inch): 0.203 (0.008)
Lead attachment: Welded
Thickness mm (inch): 0.010 (0.0004)
ELECTRICAL
Resistance, Ω @ 25°C: 345±40
Gauge Factor: 140±10
TCGF: -13%
TCR: 16%
SSGH-060-033-5000 PB
Total Length mm (inch): 1.524 (0.06)
Active Length mm (inch): 0.838 (0.033)
Width mm (inch): 0.203 (0.008)
Lead attachment: Welded
Thickness mm (inch): 0.010 (0.0004)
ELECTRICAL
Resistance, Ω @ 25°C: 5000±500
Gauge Factor: 175±10
TCGF: -23%
TCR: 47%
SSGH-060-033-500 PB
Total Length mm (inch): 1.524 (0.06)
Active Length mm (inch): 0.838 (0.033)
Width mm (inch): 0.203 (0.008)
Lead attachment: Welded
Thickness mm (inch): 0.010 (0.0004)
ELECTRICAL
Resistance, Ω @ 25°C: 540±50
Gauge Factor: 140±10
TCGF: -13%
TCR: 15%
U SHAPED
SSGH-060-033-2000 PUB
Total Length mm (inch): 1.524 (0.06)
Active Length mm (inch): 0.838 (0.033)
Width mm (inch): 0.203 (0.008)
Lead attachment: Welded
Thickness mm (inch): 0.010 (0.0004)
ELECTRICAL
Resistance, Ω @ 25°C: 2000±100
Gauge Factor: 155±10
TCGF: -18%
TCR: 25%
SSGH-080-050-10000PUB
Total Length mm (inch): 2.032 (0.08)
Active Length mm (inch): 1.27 (0.05)
Width mm (inch): 0.33 (0.013)
Lead attachment: Welded
Thickness mm (inch): 0.010 (0.0004)
ELECTRICAL
Resistance, Ω @ 25°C: 10000±1000
Gauge Factor: 175±10
TCGF: -23%
TCR: 42%
BACKING MEMBRANE
| Backing material | FR-4 |
| Thickness |
0.127 mm / 0.005 inch |
| Temperature rating | > 250°C |
| Electrical Trace Material | 1 Oz Copper/Tin (top side only) |
THE MEMBRANE SIZE CAN BE CUSTOMISED OR REDUCED TO LESS THAN 2 mm
STANDARD GAUGE SPECIFICATION
| Materials | Doped Silicon, single crystal |
| Operating strain | +/- 3000 µm/m (standard); +/- 9000 µm/m (special) |
| Linearity | better than +/- 0.25% to 600 µm/m; better than 1.5% to 1500 µm/m |
| Operating temperature | 260°C (standard) |
IF YOU USE MORE THAN ONE GAUGE IN COMBINATION, MINIMIZE THERMAL IMBALANCE AND DRIFT BY SELECTING SETS OF THERMALLY MATCHED GAUGES
STANDARD MATCHING
| Temperature | % of base resistance |
| -18°C | +/- 0.6% |
| 25°C | +/- 0.4% |
| 135°C | +/- 0.4% |
MIL SPEC MATCHING TO TIGHTER TOLERANCE AND ADDITIONAL TEMPERATURE POINTS AVAILABLE
M1 - single backed bridge (2 or 4 gauges)
M3 - set of three backed bridges
M2 - set of two backed bridges
