🔍 Key Concepts

• Role of magnetic pickups in rotating machinery • Difference between gas generator speed and power turbine speed in a split‑shaft gas turbine like the LM2500 • Typical inputs needed to calculate engine torque on marine gas turbines

💭 Think About

• On an LM2500, which rotating components would produce a measurable tooth or notch signal that a magnetic pickup can read? • Is torque usually measured directly by magnetic pickups, or is it typically derived from other kinds of sensors or strain measurements? • Do magnetic pickups sense rotational speed, load, temperature, or pressure?

✅ Before You Answer

• Confirm that magnetic pickups sense passing teeth/notches to produce a frequency signal proportional to rpm. • Distinguish clearly between gas generator (N1/Ngg) speed and power turbine (N2/Npt) speed sensing on the LM2500 layout. • Verify whether torque on this engine type is obtained from magnetic pickups or from other torque‑measuring arrangements.