Acceleration and Frequency range for Accelerometer

[wisjaf12]

Hello All

The phonomena that I want to measure the vibration for has the following expected charectaristics:

Maximum Expected acceleration =  1.5 g

The frequency range could be less that 0.1 Hz

Now I want to decide the right IEPE accelerometer for this measurement with high accuracy. With what acceleration range and frequency range should I choose my accelerometer???

Thank you

[Henrik_Volkers]

The low frequency range make it challenging 😉

What type of signal conditioning do you plan to use?

A lot of IEPE conditioner have high pass characteristic with a 3dB cut in the 0.1 Hz range, just like most of the IEPE accelerometers.

Resolution and upper frequency limit ?

Other environmental needs?  (How do you want to mount the sensor?, temperature range? )

Really cheap sensors are MEMS based, have +-2g and operate from DC up to 300Hz (look at Analog Devices, Freescale, etc)
 and have a ratiometric or 0-5V output.

[preston_johnson]

The NI 9232 module has a AC Coupling Filter at 0.1Hz, and accelerometers designed for Wind Turbines also have a low frequency range. 

Consider this accelerometer

https://www.ctconline.com/__500_mv_g_accelerometer___low_frequency.aspx

[wisjaf12]

Hello Preston_Johnson

Is this an IEPE accelerometer????  I am asking because the NI9232 is only designed for IEPE sensors as you know.

[preston_johnson]

Yes it is an IEPE sensor. 

The 9232 works with IEPE sensors, as well as any other sensor where dynamic measurements are desired.  The 9232 has +/- 30V range, 4ma of IEPE (when IEPE is turned on), and options for AC coupling (0.1Hz) and DC coupling.  We use the module for IEPE accelerometers, mems accels (DC powered), proximity probes (output of demodulator), current probes, microphones, dynamic pressure, charge coupled accelerometers using an in-line IEPE to charge converter, and really any dynamic measurement whose sensor is +/- 30V range. 

The input configuration options are IEPE with AC coupling, AC coupling, DC coupling. 

Regards,

[wisjaf12]

Preston_Johnson

I really appreciate your help and I will consider this sensor. Do they sale the connection cable with it? How do you connect this sensor to the NI9232 which is as you know screw terminal.

Regards

[preston_johnson]

Yes - CTC sells cables as well.  You would want  one with bare leads to easily connect into the 9232 module screw terminal connector. 

Preston

[wisjaf12]

Preston_Johnson

Thank you so much you helped me so much by your technical replies.  I appreciate your help.