Photo of Model 4400.

Embedment Jointmeters

Model 4400

The Model 4400 Embedment Jointmeter is designed for use across construction joints such as those between adjacent blocks in a concrete dam. It is normally embedded across the joint to monitor the expansion or contraction of the joint. The use of internal universal joints allows for a degree of shearing motion.

Specifications
Standard Ranges¹ 12.5, 25, 50, 100 mm
Resolution 0.025% F.S.
Accuracy ±0.1% F.S.
Nonlinearity <0.5% F.S.
Temperature Range −20°C to +80°C
Lengths × Diameter 415, 415, 415, 551 × 51 mm

¹Other ranges available on request.

Photo of Model 4410.

Strandmeters

Model 4410

The Model 4410 Strandmeter is designed to measure strains in tendons and steel cables. Two clamps at each end of the strandmeter hold it firmly onto the cable. Various size clamps are available.

Specifications
Standard Range 3 mm (15,000 µε)
Resolution <5 µε
Accuracy ±0.1% F.S.
Nonlinearity <0.5% F.S.
Temperature Range −20°C to +80°C
Length × Diameter 203 × 45 mm

Photo of Model 4415.

3D Crackmeters

Model 4415

The Model 4415 3-Dimensional Crackmeter is a simple and rugged instrument designed to manually measure the displacement across cracks and/or expansion joints in three directions.

Specifications
Mechanical Range 0-12.5 mm, in each X, Y, Z axis
Distance Between Anchors 12.5 mm nominal
Material stainless steel
Anchors #4 rebar
Anchor Dimensions (Ø × H) 12 mm × 150 mm

Photo of Model 4420.

Crackmeters

Model 4420

The Model 4420 Crackmeter is intended to measure movement across surface cracks and joints. It is installed by grouting, bolting, or bonding two threaded anchors (with ball joints) on opposite sides of the crack and then attaching the ends of the gage to the anchors.

Specifications
Standard Ranges¹ 12.5, 25, 50, 100, 150 mm
Resolution 0.025% F.S.
Accuracy ±0.1% F.S.
Nonlinearity <0.5% F.S.
Temperature Range −20°C to +80°C
Diameter 8 mm (shaft) / 25 mm (coil)
Lengths² 325, 333, 379, 543, 685 mm (transducer)

¹Other ranges available on request.

²Length dimensions are in mid-range position.

Photo of Model 4422.

Micro Crackmeter

Model 4422

The Model 4422 is a miniature crackmeter intended to measure displacements across surface cracks and joints. It has been specially designed for applications where access is limited and/or where monitoring instrumentation is to be as unobtrusive as possible (e.g. on historical structures or buildings).

Specifications
Standard Range 4 mm (±2 mm)
Resolution 0.025% F.S.
Accuracy ±0.1% F.S.
Nonlinearity <0.5% F.S.
Temperature Range −20°C to +80°C
L × Diameter 120 × 7.9 mm

Photo of Model 4425.

Convergence Meters

Model 4425

The Model 4425 Convergence Meter is used to monitor closures in underground excavations, tunnels, etc. It is comprised of a spring tensioned transducer, turnbuckle, connecting rod (stainless steel, fiberglass or graphite), rod clamp, and a pair of stainless steel eyebolts.

Specifications
Standard Ranges¹ 12.5, 25, 50, 100, 150 mm
Resolution 0.025% F.S.
Accuracy ±0.1% F.S.
Nonlinearity <0.5% F.S.
Temperature Range −20°C to +80°C
Transducer Lengths² 360, 360, 508, 838, 1260 mm

¹Other ranges available on request.

²Transducer length dimensions are without turnbuckle.

Photo of Model 4427.

Long Range Displacement Meters

Model 4427

The Model 4427 Long Range Displacement Meter is ideally suited for the measurement of large displacements associated with landslides. The Model 4427 can also be used for monitoring the movement of boulders, snow, etc., on unstable slopes.

Specifications
Standard Range 1, 2 m (without resetting)
Resolution 0.025% F.S. (0.25 mm for 1 m range)
Accuracy ±0.1% F.S.
Temperature Range −30°C to +60°C
L × W × H 610 × 152 × 152 mm

Photo of Model 4430.

Deformation Meters

Model 4430

The Model 4430 Deformation Meter with flanged ends is designed to measure longitudinal deformation in dams and embankments. It can also be grouted or held in place by hydraulic anchors to measure deformations in boreholes (over the gage length). Gage lengths from 0.5 to 100 meters are available.

Specifications
Standard Ranges¹ 25, 50, 100, 150, 300 mm
Resolution 0.025% F.S.
Accuracy ±0.1% F.S.
Nonlinearity <0.5% F.S.
Temperature Range −20°C to +80°C
Length × Diameter 1 m (standard); varies × 27 mm (pipe), 51 mm (flange)

¹Other ranges available on request.

Photo of Model 4435.

Soil Extensometers

Model 4435

The Model 4435 Soil Extensometer is designed to be installed, in series, to measure horizontal strain and settlements in earthfill or rockfill dams. The 4435 has flanges on either end, which enable a series of extensometers to be bolted together forming long strings of sensors so that complete profiles of deformation or settlement can be monitored.

Specifications
Standard Ranges¹ 25, 50, 100, 150, 300 mm
Resolution² 0.025% F.S.
Accuracy ±0.1% F.S.
Nonlinearity <0.5% F.S.
Temperature Range −20°C to +80°C
Minimum Gage Length 300 mm
Diameter 27 mm (pipe), 33 mm (slip coupling), 51 mm (flange)
Flange (L × W × H) 610 × 75 × 75 mm

¹Other ranges available on request.

²Resolution depends on readout equipment.

Photo of Model 4450.

Displacement Transducers

Model 4450

The Model 4450 Displacement Transducer provides remote readout capability for borehole extensometers. They are particularly useful where other types of vibrating wire sensors are used and/or for installations where long cable runs are required. The Model 4450 can also be installed between borehole anchors, in conjunction with the requisite length connecting rod, to provide a permanent, in-place incremental extensometer.

Specifications
Standard Ranges¹ 12.5, 25, 50, 100, 150, 300 mm
Resolution 0.025% F.S.
Accuracy ±0.1% F.S.
Nonlinearity <0.5% F.S.
Temperature Range −20°C to +80°C
Lengths² × Coil Diameter 210, 212, 270, 410, 550, 815 mm × 19 mm

¹Other ranges available on request.

²Length with shaft fully retracted.

Products

Please Note: Geokon maintains an ongoing policy of design review and reserves the right to amend products and specifications without notice. Various instruments are discontinued over time and replaced with new, updated models.