AA material used between the face of a search unit and the test surface to permit or improve the transmission of ultrasonic vibrations from the search unit to the material being tested is called:

AA material used between the face of a search unit and the test surfac

1.	AA material used between the face of a search unit and the test surface to permit or improve the transmission of ultrasonic vibrations from the search unit to the material being tested is called:
A.	A wetting agent
B.	A couplant
C.	A acoustic transmitter
D.	A lubricant
Answer» C. A acoustic transmitter