Built-in hydraulic cylinder magnetostrictive displacement sensors deliver accurate position feedback for excavators, cranes, loaders, and concrete pumps. Common model families such as HMDS-50, HMDS-80, and HMDS-100 cover strokes from 50 mm to 2000 mm. Selection depends on stroke, mounting thread, output signal, and pressure rating. Standard specifications include 12-24 VDC supply, 4-20 mA, SSI, or CANopen output, 0.01 mm resolution, repeatability of +/-0.01 mm, and nonlinearity within +/-0.02% FS. The stainless-steel pressure rod resists hydraulic oil, vibration, and shock. The IP67 or IP69K housing supports demanding outdoor operation. Rated pressure is 35 MPa, peak pressure is 50 MPa, and operating temperature is -40 to +85 C. Common mounting uses an M18 x 1.5 thread with a compact flange. For construction machinery, the sensor must match cylinder bore, stroke, and controller interface. Correct model and specification selection improve boom control, bucket positioning, safety, and service life. Installation should avoid strong magnetic fields and ensure proper grounding. Regular inspection of seals, cable, and connector helps maintain accurate displacement measurement on harsh job sites. Model codes often identify stroke, thread, output, and connector; for example, HMDS-80-600-M18-CAN means an 80 mm cylinder series, 600 mm stroke, M18 thread, and CANopen interface, while custom cable lengths and connectors are available for OEM machinery. Extra protection ensures reliable use.