GEOSTRING In Place MEMS Inclinometer

The GEOSTRING system consists of a number of sensor nodes in a vertical string installed in either 70mm (2.75-inch) diameter inclinometer casing or in 38mm (1.5-inch) diameter Schedule 40 PVC pipe.

The pipe or casing provides access for subsurface measurements. The joints between each sensor are robust, allowing the system to maintain a consistent orientation of all the nodes, regardless of whether it is installed in ABS inclinometer casing or PVC pipe. 

The pipe or casing is typically installed in a vertical borehole that passes through a suspected zone of movement. The nodes are spaced at 0.61 m (2 ft) intervals and provide a reading resolution similar to a  traversing probe. The system spans the zone of movement occurs, the pipe/casing moves as well, changing the inclination of the nodes inside.

Inclination measurements from the nodes are processed to provide graphs of the casing profile and changes in the profile. Changes indicate displacement (movement).

The system requires casings, GEOSTRING segments, a suspension kit, a bottom plug and a jumper cable. 

Nodes, cables, connectors and gage rods are exceptionally durable, making it practical to remove the systems at the end of the project and redeploy them on other projects.

The GEOSTRING system is connected to a SENSLOG data acquisition system, and readings are transmitted to processing software that can trigger alarms based on displacements or rate of change. 

A number of Campbell Scientific data loggers can be integrated in a Roctest Senslog for GEOSTRING systems.Two GEOSTRING systems can be connected on a CR6 or a CR1000X. With an MD485 module per GEOSTRING system, the CR1000 can read up to five systems, the CR800 three systems and the CR300 one system.

GEOSTRING systems have joints capable of bending to 90°, allowing for a compact shipping option. Five segments, each 3.048 meters (10 feet) long, can be shipped in a carton measuring approximately 64 x 64 x 64 cm (26 x 26 x 26 in) and which weigths less than 22 kilograms (50 pounds). Because of its compact size, the system can be shipped via standard overnight service.

Available Products

GEOSTRING In Place MEMS Inclinometer
[GEOSTRING In Place MEMS Inclinometer]
Please contact for pricing

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Product Details

SPECIFICATIONS

Sensor type

MEMS (Micro Electro-Mechanical Systems) tilt sensors for inclination readings
Thermistor for temperature readings

Calibrated Range

±30 degrees from vertical over a temperature range of -10°C to +40°C

Resolution with SENSLOG

9 arc seconds or 0.04 mm/m using the CR1000 data logger

Repeatability

±82 arc seconds or ±0.4 mm/m

Power requirements

Minimum supply voltage of 10 Vdc. Maximum supply voltage of 30 Vdc.
Digital RS485 signal requires Campbell Scientific data logger

Housing

Stainless steel, 32 mm diameter, waterproof to 2 MPa

Weight

0.54 kg per 0.6m (1.2 lb per 2 feet) gauge length

Waterproof

Waterproof to 2 MPa (300 psi)

Signal Cable

Jumper Cable for connecting the system to the datalogger.
Connectors are rated to 70 MPa (10,000 psi)

Casing

70 mm (2.75 in) diameter casing
38 mm (1.5 in) Schedule 40 PVC Pipe

Data Logger

Compatible with CR6, CR300, CR800, CR1000 & CR1000X Data Loggers
MD485 RS-485 Interface required for CR300, CR800 & CR1000 Data Loggers

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Documentation

Name
Description
Action
Document Name: GEOSTRING™ In Place MEMS Inclinometer 
Document Type: Spec Sheet