Shield tunneling demands continuous, reliable level control for slurry, bentonite, water, foam, and hydraulic fluids. A magnetostrictive level gauge is a strong choice for these harsh duties. Its waveguide and magnetic float provide direct, high-accuracy measurement with no mechanical gears, so vibration, dust, mud, and long cable runs have little effect on performance. The sensor usually offers 0.05% FS accuracy, repeatability, and multi-point output, making it suitable for balance tanks, slurry circulation, grout stations, and TBM auxiliary systems. Stainless steel housings, IP67/IP68 protection, anti-corrosion probes, and explosion-proof options help it survive humidity, washdown, and confined underground spaces. Standard 4-20 mA, HART, RS485, or Modbus outputs connect easily to PLCs and monitoring platforms for real-time alarms and automatic control. Because the signal is absolute, power interruption does not cause data loss, and the gauge needs no periodic recalibration. For shield tunneling, choose probe length, float density, and wetted materials according to slurry abrasiveness, tank depth, and pressure. A guided float design helps suppress false readings caused by foam or surface waves. Correct installation matters: keep the float free from buildup, avoid strong vibration, and set the range to cover normal and alarm levels. With stable signals and low maintenance, these gauges improve safety, reduce downtime, and support process control in shield tunneling projects.