Model
3900 Embedment Strain Gage
The Model 3900 Embedment Strain Gage is designed for the measurement
of dynamic strains in concrete structures, asphalt roadways and soils.
It comprises a full bridge strain gaged proving ring coupled, between
two flanges, with a spring and shaft. When the flanges move relative
to one another, the tension in the spring changes and hence the strain
in the proving ring. A PVC tube serves as a protective housing and holds
the gage at the desired initial tension.
| Specifications | |
| Standard Range | 5000 microstrain |
| Sensitivity | 0.125 mV/V nominal |
| Accuracy | ±0.025% F.S. |
| Nonlinearity | < 0.5% F.S. |
| Temperature Range | –20°C to +80°C |
| Active Gage Length* | 203 mm |
| *Other lengths available on request | |
Model
4000 Arc Weldable Strain Gage
The Model 4000 Strain Gage is designed primarily for arc welding to
steel structures such as tunnel linings, excavation bracing, piles and
bridges. The gage has a 150 mm gage length (longer or shorter versions
are also available) a 3000 microstrain range and a 1 microstrain sensitivity.
The gage can be adapted for bonding to concrete or for bolting to steel
surfaces by modification of the end blocks.
| Specifications | |
| Standard Range | 3000 microstrain |
| Sensitivity | 1.0 microstrain |
| Accuracy | ±0.1% F.S. |
| Nonlinearity | < 0.5% F.S. |
| Temperature Range | –20°C to +80°C |
| Active Gage Length* | 150 mm (5.875in.) |
| *Other lengths available on request | |
Model
4100 • 4150 Spot Weldable Strain Gages
The Model 4100/4150 Strain Gage has a 51 mm gage length (3000 microstrain
range, 1 microstrain sensitivity) and is designed to measure strains
in steel structures (4100) and on reinforcement bars (4150) where space
may be limited. The gage is installed quickly and easily by means of
a capacitive discharge spot welder or, for short-term use, with special
epoxy adhesives; the latter method of attachment permits the use of
this gage on concrete.
| Specifications | |
| Standard Range | 3000 microstrain |
| Sensitivity | 0.5 to 1.0 microstrain |
| Accuracy | ±0.1% F.S. |
| Nonlinearity | < 0.5% F.S. |
| Temperature Range | –20°C to +80°C |
| Active Gage Length | 51 mm |
Model
4200/4210/4202 Concrete Embedment Strain Gages
These Strain Gages are designed for direct embedment in concrete. The
4200 (standard model) has a 153 mm gage length and 1 microstrain sensitivity
and is commonly used for strain measurements in foundations, piles,
bridges, dams, tunnel linings, etc. The 4210 has the same range as the
Model 4200 but has a 250 mm gage length making it particularly suitable
for use in large aggregate concrete. The 4202, with a 51 mm gage length,
is designed for laboratory use and / or where there are space limitations.
Low modulus versions, for measuring concrete curing strains, are also
available (contact Geokon for details).
| Specifications | 4200 | 4210 | 4202 |
| Standard Range | 3000 microstrain (for each model) | ||
| Sensitivity (microstrain) | 0.5 to 1.0 | 0.4 | 0.4 |
| Accuracy | ±0.1% F.S. | ±0.1% F.S. | ±0.1% F.S. |
| Nonlinearity | < 0.5% F.S. | < 0.5% F.S. | < 0.5% F.S. |
| Temperature Range¹ | –20°C to +80°C (for each model) | ||
| Active Gage Length | 153 mm | 250 mm² | 51 mm |
| ¹Model 4200 high temperature version (up to 200°C) available
on request ²Other lengths available on request |
|||
Model
4200HT High Temp. Embedment Strain Gage
The Model 4200HT High Temperature Embedment Strain Gage is similar to
the standard Model 4200 but is constructed using components that can
be used at temperatures up to 200°C. It is particularly useful for measurements
in autoclaved spun concrete piles.
| Specifications | |
| Standard Range | 3000 microstrain |
| Sensitivity | 1.0 microstrain |
| Accuracy | ±0.1% F.S. |
| Nonlinearity | < 0.5% F.S. |
| Temperature Range | –20°C to +200°C |
| Active Gage Length* | 153 mm |
Model
4911 • 4911A Rebar Strainmeters
The Model 4911 Rebar Strainmeter is designed for measuring strains in
foundations, slurry walls, precast piles, caissons, bridge abutments,
tunnel liners, etc. The standard Model 4911 (#4 rebar), known as the
“Sister Bar," is installed alongside structural rebar. Larger models
(4911A) are available for welding directly into structural rebar. Where
short-term dynamic measurements are to be made, bonded resistance strain
gages can be substituted, or added (Model 3911/3911A).
| Specifications | |
| Standard Range | 2500 microstrain |
| Sensitivity | 0.4 microstrain |
| Accuracy | ±0.25% F.S. |
| Nonlinearity | < 0.5% F.S. |
| Temperature Range | –20°C to +80°C |
| Sizes | (4911) #4 Rebar
(Sister Bar) |
| Length | (4911) 1384 mm (4911A) 1105 mm |