User's Manual

M2540-92000-01 A M2540 Ultrasound System Field Service Manual Page 58
Theory of Operation: Transducer Safety Testing: Test Setup and Theory
• If the transducer sheath is compromised, its resistance is close to that of the ground wire.
Transducer leakage current equaling 80% or more of ground wire leakage current indicates a
fault or break in the transducer insulation.
Sheath integrity is tested this way because there could be a break in the transducer sheath
causing significant I
transducer
, and yet that leakage current could still be within acceptable limits.
Comparison to the ground wire leakage current is the only way to ensure sheath integrity.