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USB-6225 Bizarre Ouput - Is it Broken?

Hello,

We have a USB-6225 that has been previously used on many occasions to gather strain guage data.  We are currently trying to use it to acquire data from a dynamic hydrophone (having previously determind with the hydrophone manufacturer that the input characteristics of the device are appropriate) but I am getting some very odd behavior from the DAQ device.

We are configured to read the hydrophone differentially (also tried RSE with the same response) at 10kHz in a continuous sampling mode.

When you hit run.....the voltage trace shows an oscillation over ~200mV that decreases to dead quiet in three decaying oscillations.  After several seconds, noise appears on the channel and tapping the hydrophone shows peaks consistent with the excitation.  After several more seconds......dead quiet.  Like.....the y-aix autoscales to the 1E-27 range and still shows DEAD QUIET that continues until you stop the routine.  I know even an open circut should show SOME noise or voltage drift.

We have checked all cables and swapped out with others....all of which was working just fine when the unit last went into its padded case.  The fact that I'm seeing dead quiet tells me that the problem is unrelated to the sensor configuration and seems to be a problem with the unit?  I.e......its not getting any samples which is why its showing absolutely 0.0000000000 output.

Any ideas?  Driver issue?  

Thanks,

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link(s) to datasheets of the sensor and conditioning?

connection schematic ?

DAQ configuration VI?

 

Some hydrophones want constant current supply, bridges usually const. voltage supply ......

 

Greetings from Germany
Henrik

LV since v3.1

“ground” is a convenient fantasy

'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'


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