is it possible to connect accelerometer to ni usb 6008

[mujo]

Hello,

I have NI USB 6008 card and Acceleration  sensor BCK co type AS-065.

Is it posibble to get data with this equipment?

Thanks

Emir

[Alex A.]

Hi Emir,

You can use the USB-6008 with your accelerometer.  However, your accelerometer needs an excitation that cannot be provided by the USB-6008 and thus you will need an external power source for the sensor. Page 3 of this document  has the specifications for your accelerometer and detail the power requirements for it.  You would use the power supply to provide the excitation to the accelerometer and then use the USB-6008 to input the voltage changes detected. Hope this helps.

[mujo]

Thanks for answer.

But, still I have a poroblem. I have only 2 wires for connection of probe as-065 to this NI USB 6008 card.

Can I connect it in series (series connection of : power supply , probe as-065 and analog input of NI USB 6008 card).

I am affraid I will destroy something?

If I can not connect it in series how can I do it?

Thanks for answers?

Emir

[Vanessa L]

Hi Emir,

By looking at the document that Alex provided for your sensor, I can't seem to find what type of power requirements your AS-065 sensor has.  Usually we do not recommend using something like the USB-6008 in order to do accelerometer measurements.  Instead, it would be better to have an accelerometer module with USB in order to do the aquisition since those modules provide an internal excitation.  Here is a link to Sensor Fundamentals and there is a topic on accelerometers that you might want to read through.  If your device needs some type of excitation, you might need to look if there is a channel on the device that accepts the positive and negative terminals of the power supply.  Then you could connect the two wires coming out of the sensor to a positive and negative terminals of analog input of the USB-6008.  Also if you look in the user manual, there is an output on the card that provides 5 V voltage that you could also wire to your sensor for excitation.  Although I'm not sure if your device accepts current or voltage excitation which you will need to find in that sensor's documentation.  Hopefully this information was helpful!

[Wilfried_71]

I confirm that it's not possible to plug a accelerometer in a card like a USB 6008 ! There's a lot of reasons :

- Usually, the A/D convertissor need to be a 24 bit (on a +/- 5V input), not a 12 bit, because the acceleration measure need a high accuracy

- There's always hardware filters in a accel conditioning box, in order to avoid noise and so on ...

- The sensor need a constant supply current (usually 2 mA) and the conditionning box read the

[Wilfried_71]

Sorry, I send the message too soon :

- The sensor need a constant supply current (usually 2 mA) and the conditionning box read the variation of voltage ...

- Some of accelerator need a charge amplificator to convert pC in mV ...

- The acceleration signals are very often dynamic signals, so you need a acquisition frequency rather high, something like 25 or 50 kHz ... so 10 kHz is a little bit slow.

So, the better think to do is to have a special accel conditioning box like the cDAQ with the 9233 module.

Bye