User Manual for AML Oceanographic’s Micro SV & P Sensor
31
Problem:
The instrument communications are intermittent.
Solutions:
• The communications cable has been inserted incorrectly. Check the cable connections
at the computer and the instrument. Examine the pins on the instrument connector for
bent or corroded pins.
• The communications cable has a fault. Check the continuity of the cable with an
ohmmeter while flexing the cable. Short cables (< 3 meters) should have less than ½
ohm from end to end on each conductor. The cable should have a short between pins 6,7
and 8. Refer to the wiring diagram in Appendix B. If any of these conditions are not met
replace the cable.
• Incorrect power is being applied to the instrument. Check with a volt-ohm-meter for
proper supply voltage. The voltage range is from +8 to +16 VDC. Please refer to the
appendix 'C' Electrical Wiring Diagram.
Problem:
The sensor readings are noisy.
Solutions:
• There are nearby electromagnetic noise sources. Move the instrument to a new location
or move the noise source. Refer to section 6.2.
• If only one sensor reading is noisy determine which sensor channel it is and refer to the
“____ sensor readings are incorrect” section for that sensor, which are listed below.
• The power supplied to the instrument is noisy. Change the power supply to a more
regulated power supply or use a battery.
Problem:
The sound velocity sensor readings are incorrect.
Solutions:
• The sound velocity sensor has a bubble or debris between the transducer and reflector
plate. Clear the obstruction.
• The sound velocity sensor has completely dried out and has not been allowed to wet
before use. Wipe the transducer face while submerged in water to remove tiny air
bubbles and allow the transducer to soak for several minutes.
• The sound velocity sensor is faulty. Examine the sensor for cracks in the epoxy. If
cracked the sensor must be repaired and re-calibrated. Examine the sensor for deposits of
dirt or marine growth . Clean the sensor.
