How can I configure NI PCI 6221 and DAQ SCB-68 for pressure sensors?

[Jonas Weiß]

Hello everybody,

I am using the measuring board (NI PCI 6221) and DAQ SCB-68 for the data acquisition.

With the DAQ-Assistant I created AI for the voltage of pressure sensors. In a big indicator panel from this DAQ-Assistant I see the voltage for both sensors in the correct size. But if I set sensors in the blockdiagramm to control the signals for sensor one I get a wrong voltage size and for sensor 2 nothing.

How can I configure this data acquisition equipment to get the correct signals?

Thanks a lot for your help.

[Coq_Rouge]

I do not know the type of sensor you are using. But pressure transducers may have a very low output voltage(in the mVolt range). They also need an excitation voltage. Here is an introduction.

http://focus.ti.com.cn/cn/lit/an/sloa034/sloa034.pdf

Then working with pressure sensors I always use 3 stages in the circuit.

1 Instrumentation Amplifier as a preamp

2 filterstage

3 Final amp and output buffer

(you may combine stage 2 and 3)

[Jonas Weiß]

Maybe that is the solution. I will try and reply.