The TES-AN-25 inclinometer system is an accurate instrumentation system. Its datalogger has built-in data storage facilities and capability of transferring stored data to a computer. The inclinometer probe operates in a plastic grooved casing which may be “built-up” with embankment fill, inserted into boreholes or attached externally to structures or hillsides. The inclinometer casing may be installed with telescopic couplings as construction progresses providing opportunity for settlement measurements, or it may be installed with butt joints in drill holes in abutments or completed embankments if no significant settlement is anticipated