Chapter 12 — Installation of Instruments¶

12.1 Installation makes or breaks the data¶

The best-specified instrument yields useless data if installed poorly. Installation is where most monitoring programs win or lose.

12.2 Drilling and boreholes¶

Avoid smearing the borehole wall (which seals off the zone you want to measure) by using appropriate bits and methods.
Keep the borehole open and clean at the measurement zone.
Protect against collapse in软 soils.

12.3 Grouting, casing, and sealing¶

Filter packs around piezometers and inclinometer anchors must be clean and correctly graded.
Sealing (grout/cutoff) prevents water from short-circuiting down the borehole to a lower zone — a classic source of wrong readings.
Casing for inclinometers must be vertical (or known orientation) and fully grouted for good coupling to the ground.

12.4 Tubing and cable routing¶

Protect pneumatic tubing and sensor cables from damage, kinking, water, and rodents.
Label and route to accessible, sheltered readout points.
Keep cable lengths within the instrument's specified limits.

12.5 Installation records¶

For every instrument, record permanently:

Location, depth, orientation, and datum.
Strata encountered and filter-pack / seal details.
As-installed photos and as-found calibration.
Date and personnel.

These records are essential for interpretation and for replacing the instrument later.

12.6 Personnel qualifications¶

Installation is skilled work. Specify and verify the competence of those drilling, grouting, and placing instruments.

Short-circuiting destroys a piezometer

A single uncorrected path for water down a borehole can make a deep piezometer read a shallow zone. Seal meticulously; verify with a standpipe or observation well.

12.7 Key takeaways¶

Installation quality determines data quality more than sensor grade.
Prevent smearing and short-circuiting; grout and seal meticulously.
Protect and label tubing and cables.
Keep permanent, detailed installation records.