The Ivancich Inclinometer 103 is located inside the landslide at about 360 m asl, and is located in a 35 m deep borehole.

The inclinometer probe measures tilt of two orthogonal axes “A” and “B”; in particular is read the measure corresponding to the axes inclination (θ). The conversion from angular values to displacement occurs through trigonometric function. The sine function, i.e. the angular value, is derived from the value produced by sensors, in general for measure between +/-15° from the vertical. The angle θ is the inclination angle from vertical, the hypotenuse is the pace of the probe, i.e. the measuring range, or step of readings (generally 0.5 m), while the opposite side is the lateral “deviation”. The lateral displacements are calculated at each depth; for convention this value is called “lateral deviation”. The sum of successive lateral deviation is called “cumulative deviation”. The cumulative deviation variations define the inclinometer tube displacement. The incremental displacement represents the variation from each measurement interval. The cumulative displacement is the sum of the incremental displacements. The common inclinometers data graphs showing the displays cumulative lateral deformation with depth, starting at the bottom of the casing and summing increments of displacement for each measured interval up to the ground surface.

The inclinometer 103 time series provide data for the observed period from November 1998 to December 2006, and are organized as follows:

Depth (m): measured interval from the bottom of the casing up to the ground surface (0,5 m step)

Data: gg/mm/aaa

Raw data A0 – A180 – B0 – B180: numbers recorded by the probe corresponding to the values of the tube inclination relative to the vertical, projected on the planes A and B; the measure unit is expressed in digit (electrical value).

CheckSum A and B: add of the two values obtained in diametrically opposite direction at the same depth. The checksums produce a constant value, where a low standard deviation would confirm data quality.

Lateral deviation A – B – Resultant: lateral displacements are calculated at each depth

Cumulative deviation SA – SB – Resultant: sum of successive lateral deviation

Differential Lateral Deviation A Diff – B Diff – Resultant Diff: incremental displacement represents the variation from each measurement interval

Cumulative Displacement SAInt Diff – SB Int Diff – Resultant Ins Diff: sum of the incremental displacements.

The main feature of the inclinometer 103 are:

Inclinometer Tube Internal Diameter – 76.1 mm

Probe type – Sinco Digitilt Inclinometer (P/N 50302510 S/N 28447)

Probe unit – meter

Probe constant – 25000 sinα

Probe Type – Biaxial

Probe Sensors – Servoinclinometers

Shallowest depth: 1 m

Deepest Depth: 35 m

Reading Interval: 0.5 m

A0 Direction: N212

Height of the reference plan (P.R.) relative to campaign plan (p.c.): - +0.09 m

Depth probe relative to p.c.: 35 m