Application
Digitilt inclinometers are used to monitor lateral movements in embankments and landslide areas, deflections of retaining walls and piles, and deformations of excavation walls, tunnels, and shafts.
Operation
Inclinometer casing is typically installed in a near vertical borehole that passes through suspected zones of movement into stable ground. The Digitilt inclinometer probe, control cable, pulley assembly, and readout are used to survey the casing. During a survey, the probe is drawn upwards from the bottom of the casing to the top, halted in its travel at half-meter intervals for tilt measurements (two-foot intervals are used for English probes). The first survey establishes the initial profile of the casing. Subsequent surveys reveal changes in the profile if ground movement occurs. The inclination of the probe body is measured by two force-balanced servo-accelerometers. One accelerometer measures tilt in the plane of the inclinometer wheels, which track the longitudinal grooves of the casing. The other accelerometer measures tilt in the plane perpendicular to the wheels. Inclination measurements are converted to lateral deviations. Changes in lateral deviation, determined by comparing data from current and initial surveys, indicate ground movements. Plotting the cumulative changes at each measurement interval yields a high resolution displacement profile. Displacement profiles are useful for determining the magnitude, depth, direction, and rate of ground movement.
Advantages
Proven Performance: The servo-accelerometers used in Digitilt probes were designed and manufactured by Slope Indicator. They have earned a world-wide reputation for high precision, superior stability, and rugged construction.
Repeatable Tracking: The Digitilt probe is designed to travel hundreds of kilometers of inclinometer casing. To ensure consistent tracking in all types of casing, the probe is equipped with robust wheel carriages, sealed wheel bearings, and specially de-signed wheels.
Extended Installation Life: The compact size of the Digitilt probe allows it to pass through small radius curves, extending the useful life of the installation beyond that possible with most other inclinometer probes.
Computerized Calibrations: A custom designed, computerized calibration table performs thorough testing of each inclinometer probe and generates extremely accurate calibration data.
Reliable Control Cable: Digitilt control cable is durable and easy to handle, stays flexible in cold temperatures, resists chemicals and abrasion, and provides excellent dimensional stability. Flexible rubber depth marks are permanently molded to the cable jacket. The marks cannot loosen and have no rigid edges that can damage the cable jacket and conductors.
Consistent Depth Control: The pulley assembly, a recommended accessory, helps the operator achieve uniform depth control. The one-way action of its cable clamp ensures consistent positioning of the probe.
Protective Case: The stainless steel carrying case included with the probe provides good protection during transport.
System Compatibility: The Digitilt family includes a wide range of readouts and computer software, horizontal and in-place inclinometers, tiltmeters, high quality inclinometer casing, and specialized accessories.
