NI-9250 or NI-9232 for the Wilcoxon Amphenol 997-M4

[lmaurelli]

Sorry for the naive question, but it is my first time designing the acquisition of a sensor.

I would like to ask what is the proper hw for the excitation and signal conditioning of the sensor Wilcoxon Amphenol 997-M4, whose spec (997-M4 high frequency accelerometer with integral cable (wilcoxon.com) states "bias voltage output: 12 VDC"- Does the NI-9250 (+- 5V) properly handle the signal conditioning? What should I look at to check for the right compatibility?

Thank you.

[Henrik_Volkers]

both unit support IEPE,

if you only need a range up to 500g the 9250 is fine and has a higher speced stability and lower noise.. (but you dominant noise source is the sensor 😉 )

if you go for high amplitudes at high frequencies and/or longer (20m + ) cables the 9232 with its higher drive current (4mA vs 2mA) seems a better choice. 

or if you want to measure down to (or below) 0.5 Hz the 9232 has a lower high pass , however your sensor is speced with 0.5 (-3db)  as well as the 9250, so no real problem.

[lmaurelli]

Thank you for the the technical aspects mentioned.

As far as I understood, considering the mentioned sensor, its sensitivity is 10mV/g with a peak full-scale of 600g. In other words it outputs +-6 VDC (the 12VDC Bias Voltage Output mentioned in the spec).

Your rationale is that with a module whose voltage maps to +-5V satures the acceleration between 500-600g. So if they are not needed, that is not a problem, otherwise I would need the 9232.

The other rationale is about the excitation current, this depends on the cable distance and EM noise as far as I understood. In other words, if the setup is confined the 2mA excitation current should be enough.

The rationale about low and high frequencies are new and appreciated. I will investigate them.

What about the general AI 9025 module. What is it missing w.r.t the excitation and signal conditioning of the dedicated modules? What kind of HW should I integrate and how? Are there any experiences of past users I can look at?

Thank you,

Luca

[rolfk]

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@lmaurelli wrote:

What about the general AI 9025 module. What is it missing w.r.t the excitation and signal conditioning of the dedicated modules? What kind of HW should I integrate and how? Are there any experiences of past users I can look at?

Thank you,

Luca

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The NI 9025 is a cRIO chassis. Are you referring to the 9225? That has no excitation outputs at all.