Testing an instrument speed through water transducer

[Chuck - Raymarine - Moderator]

Testing an instrument speed through water transducer

The following procedure may be used to testing an instrument speed through water transducer:

- Verify that the transducer’s paddle wheel is free of marine growth and rotates freely on its shaft
- Power down the instrument or iTC-5
- Disconnect the GREEN and SHIELD transducer leads from the instrument display or instrument pod.
- Connect a multimeter to the GREEN and SHIELD transducer leads and configure the multimeter to measure continuity or resistance.
- Slowly rotate the transducer paddle wheel by hand. Note that as the paddle wheel is rotated, the multimeter should alternate between an open circuit and a closed circuit with each quarter turn. As such one complete revolution of the paddle wheel should open and close the circuit four times.

Should the multimeter respond as indicated above, then the speed sensor element of the transducer would be deemed operational. If not, then the transducer has failed and should be replaced.

RAYFAQ#