How to amplify voltage signal from a pressure transducer using PCI 6013 board

[Aj061988]

Hi,

I am working on a project that requires me to do a minute by minute record of the pressure in my experimental setup. I am using an OMEGA PX429-2.5GV pressure transducer. Data sheet enclosed. 

The data needs to be stored in an excel file or word document so that I can plot graphs/do further study later.

Would it be better to use a data logger from OMEGA and record the data? Or can I develop a program on LABView to record the data and amplify it by some way?

I am new to LABView and not that comfortable with 'electronic circuitory work'. Hence, it would be great if I get some help in developing the program.

Thanks in advance for your time and help!

AJ

[johnsold]

AJ,

You should be able to use the equipment you have.

1. Excite the pressure transducer with a clean 5 V source. (The 5 V available from the 6013 connector is connected to the logic power source and may be rather noisy.) 

2. Set the DAQ device gain to 100 ( range = +/-50 mV). With 5 V excitation the full scale output  will be 50 mV.

3. Set the DAQ device for differential inputs and wire +SIG and -SIG from the transducer to the appropriate inputs of the DAQ device.

4. Connect the ground of the transducer excitation source to the DAQ device AI Ground.

If you only want one reading per minute, consider taking one reading per second and averaging 60 readings to get the value to be saved. This will minimize the chances that a noise spike might give you a corrupted reading.

Look for examples which show how to sample your data and save it to a file. The Example Finder link is under the LabVIEW Help menu.

Lynn

[Henrik_Volkers]

In addition to Lynns suggestions:

Depending on how accurate you want to measure: Since the output is  ratiometric  (read sensitive) to the supply voltage you should read  and log the supply voltage with a second channel.

SInce the output is output-voltage(function of pressure)/supply-voltage!  ( If you only need half of the range of this sensor I recommend to use a 10V supply in the +-50mV input range)

The bandwith of the sensor is about 1kHz so you should sample with at least 2kHz, better 5kHz or 10kHz

Reading 10 000 values a second for one value a minute seems to be a bit oversized but brouse this board for 'noise' ....   it will be boring for the PC anyway 😉 😄  

Read one second (10 000 samples) and store the mean value (+supply voltage) .

The LabVIEW examples (found under HELP) are a good starting point.  DAQmx_AI_ voltage continous read.vi sound like a good starting point. (That stores tdms data without mean-calculation, however ... come back here if you run into questions)

There are some more points .... reading mV  with high impedance (5k Ohm)  and 5-10V with multiplexed ADCs, ghosting,  but just start and come back.    (Prepare to post data and vi 😉  )