The hydraulic settlement gauges are designed for continuous, high-precision monitoring of differential settlements and vertical displacements in geotechnical and structural works. The instrument enable simultaneous measurement of multiple points through a network of pressure sensors hydraulically connected to a reference reservoir installed in a stable location. This configuration allows highly accurate detection of elevation differences between measurement points, providing essential information on soil–structure interaction throughout all stages of the structure’s service life. The technology, based on high-resolution pressure transducers, ensures reliable measurements over long periods and under variable environmental conditions. It is particularly suitable for automated monitoring, with full integration into data acquisition and remote monitoring systems. Thanks to the closed hydraulic circuit configuration, elevation changes at the sensors are converted into pressure variations of the fluid, enabling extremely sensitive and immediate settlement measurements. The use of compensation lines also reduces the influence of barometric and thermal variations, improving long-term reading stability. The GESTECNO hydraulic settlement circuit consists of a sensitive reference station, measurement “cups” distributed along the structure, hydraulic tubing, and electrical connections. It is designed to ensure easy installation, operational reliability, and flexible configuration according to project requirements. Its structural robustness and modular design make it suitable for demanding environments, ensuring high performance even under complex operating conditions. The device is also available in high-accuracy versions (ASI-307 and ASI-317), with each internal sensor tested in a climatic chamber and individually calibrated to compensate for thermal effects over a wide temperature range.