os3150/55 Optical Strain Gages – Weldable FBG Strain Gages with Optional Temperature Compensation
Rugged, spot-weldable fiber Bragg grating strain gages; the os3155 adds an integrated FBG for temperature compensation.
- Strain Sensitivity
- ~ 1.4 pm/με
- Strain Sensitivity
- ~ 1.2 pm/με
- Gage Length
- 75 mm
- Gage Length
- 50 mm
Overview
The os3150 and os3155 are spot-weldable optical strain gages based on fiber Bragg grating (FBG) technology, designed for outdoor installations on steel structures. A stainless steel carrier holds the FBG in tension without epoxy and protects the fiber during installation, so long-term stability is ensured by design.
The os3155 includes a second integrated FBG for active temperature compensation. Because the strain and temperature measurements are made in close proximity, compensation is more accurate, and installation costs fall by reducing the need for additional cables, splices and temperature gages. For temperature compensation with the os3150, an FBG temperature sensor such as the os4350 can be connected in series. Both gage types can be combined in one installation.
Installation takes a few minutes. Since the gages are welded in place, they can be used immediately after attachment without waiting for adhesives to cure. Armored cables lead to and from each gage, and optional protection fittings protect splice-free series connections to other optical strain, temperature or acceleration sensors on the same fiber. The gage package is typically covered with a protective material for long-term protection.
In side-by-side comparisons with foil strain gages, the os3150 and os3155 are equally sensitive and accurate, with a greater strain range and 100 times more fatigue life. The gages can be used alone or in series as part of an FBG sensor array, and multiple gages can be arranged at 0, 45 and 90 degrees for strain rosette measurements.
Models in this series
| Model | Description | |
|---|---|---|
| os3150 |
os3150 Optical Strain Gage – Rugged Spot-Weldable FBG Strain Sensor
Rugged, spot-weldable fiber Bragg grating (FBG) optical strain gage with a 75 mm gage length and ± 2,500 με strain limits. |
Details → |
| os3155 |
os3155 Optical Strain Gage with Integrated Temperature Compensation (FBG)
Rugged, spot-weldable FBG optical strain gage with a second integrated FBG for temperature compensation, for steel structures. |
Details → |
Key Features
- Rugged, permanent weldable package
- Option for integrated temperature compensation FBG sensor; close proximity improves accuracy of strain measurement
- Armored cable integrated with sensor package for fiber protection and strain relief
- Fast, simple, repeatable installation
- Double-ended design supports multiplexing of many sensors on one fiber
- Qualified to same rigorous standards used for comparable electronic gages
- Gage installation and protection achieved with same methods as conventional electronic gages
- No epoxies holding the fiber to the carrier
- Included in ENLIGHT's sensor templates for quick optical to mechanical conversions
Specifications
|
Strain Sensitivity
os3150 |
~ 1.4 pm/με
Actual gage factor provided with gage |
|---|---|
|
Strain Sensitivity
os3155 |
~ 1.2 pm/με
Actual gage factor provided with gage |
|
Gage Length
os3150 |
75 mm |
|
Gage Length
os3155 |
50 mm |
| Operating Temperature Range | -40 to 80° C |
| Strain Limits | ± 2,500 με |
| Fatigue Life | 100 x 10^6 cycles, ± 2,000 με |
|
Integrated temperature compensation sensor
os3155 |
Yes
os3150 has no integrated temperature compensation sensor; use a series FBG temperature sensor such as the os4350 |
| Dimensions |
See Diagram Below
Dimensional diagram in datasheet |
|---|---|
|
Weight
os3150 |
15 g
Without cable |
|
Weight
os3155 |
17 g |
| Carrier Material |
302 Stainless Steel
Web page spells it '302 Strainless Steel'; datasheet wording used |
| Cable Length | 1 m (± 10 cm), each end |
| Cable Type | 3 mm armored cable |
|
Fiber Type
os3150 |
SMF 28 Compatible |
|
Fiber Type
os3155 |
SMF-28
Earlier os3155 datasheet states SMF28-Compatible |
|
Connectors
os3150 |
Optional |
|
Connectors
os3155 |
FC/APC and Connector Protection Fitting Optional |
| Cable Bend Radius | ≥ 17 mm |
|
Fastening Methods
os3150 |
Spot Weld
See installation guide for details |
|
Fastening Methods
os3155 |
Spot Weld, Epoxy Mount
Earlier os3155 datasheet lists spot weld only |
| Peak Reflectivity (Rmax) | > 70% |
|---|---|
| FWHM (- 3 dB point) | 0.25 nm (± .05 nm; apodized grating) |
| Isolation |
> 15 dB
@ ± 0.4 nm around center wavelength |
|
Ordering code
os3150 |
os3150-wwww-1xx-1yy
Example: o3150-1552-1FC-1FC |
|---|---|
|
Wavelengths (wwww)
os3150 |
Standard - 1460 to 1620 nm in 4 nm intervals
+/- 1nm |
|
Ordering code
os3155 |
os3155-tttt/ssss-1xx-1yy
Example: o3155-1512/1516-1FC-1FC |
|
Strain/Temp Wavelengths (tttt/ssss)
os3155 |
Standard - 1462/1466, 1472/1476, 1482/1486, 1492/1496, 1502/1506, 1512/1516, 1522/1526, 1532/1536, 1542/1546, 1552/1556, 1562/1566, 1572/1576, 1582/1586, 1592/1596, 1602/1606, 1612/1616
+/- 1nm. Earlier os3155 datasheet lists 1582/1588 instead of 1582/1586 |
| Cable length (1xx / 1yy) |
1 m Standard, Cable Length
Cable 1 and Cable 2, each end |
Applications
- SHM for civil and geotechnical structures
- SHM for energy systems
- Structural test and model validation
- Structures (bridges, dams, tunnels, mines, buildings, oil platforms)
- Energy (wind turbines, oil wells, pipelines, nuclear reactors, generators)
- Transportation (railways, trains, roadways, specialty vehicles, cranes)
- Marine vessels (hull, deck, cargo containers)
- Aerospace (airframes, composite structures, wind tunnels, static and dynamic tests)
- Homeland security (perimeter intrusion, heat detection, security gate monitoring)
- Strain rosette measurements
Options & Accessories
| Option | Description |
|---|---|
| UT | Unterminated — Termination type for cable 1 (xx) or cable 2 (yy) |
| FC | FC/APC Connector — Termination type for cable 1 (xx) or cable 2 (yy) |
| PF | FC/APC Connector with Protection Fitting — Termination type for cable 1 (xx) or cable 2 (yy) |