Measuring 4-20 mA signal from a Pressure Sensor using NI 9219 DAQ

[SidBeckham07]

Hi ,

I have a Pressure sensor ( Omega PX119 150GI) which outputs current in the Range of 4-20 mA and a measuring range of 0-150 psi. I also have a Compact DAQ with a USB serial port and an NI 9219 Universal DAQ. Could someone please let me know how to make the connections and measure the pressure using LabVIEW?  I am fairly new to this topic and help would be much appreciated.

Thank you so much in Advance,

Cheers,

Sid

[santo_13 · Accepted solution]

I am just consolidating the information from multiples sources

1. NI 9219 Getting started guide - https://www.ni.com/pdf/manuals/374473f.pdf
2. Omega PX119 sensor - http://www.farnell.com/datasheets/2920183.pdf

Your sensor specifies the pinout as highlighted below,

For each channel in NI 9129 DAQ, below is the pinout to connect a sensor in the current mode.

With these two pieces of information, you have to connect Sensor+ to HI and Sensor- to LO.

In order to use LabVIEW to collect data, use the below-highlighted example, (navigate to Help->Find Examples...)

[SidBeckham07]

Hi Santosh,

Thank you so much for your reply. 

I had a few doubts regarding configuring the sensor in LabVIEW.:

- When I choose current continuous sampling, How do I convert that signal into Pressure?

- When I choose a Pressure VI example, It asks for electrical units in volts. What should I give the values as since my sensor outputs current.

I have attached picture for both cases. Could you please help me out with this issue.

Thank you so much in advance,

Regards,

Sid

[SidBeckham07]

Hi Santhosh,

Thank you so much for your help. I configured the sensors to work using NI 9219 DAQ.

Regards,

Sid

[erolfe993]

Hi Sid,

Did your pressure sensor require a voltage supply? 

I have a Hydrotechnik Pressure Sensor which requires a supply of 12-32VDC and gives an output of 0-10V. The supply is higher than the internal excitation voltage that the NI 9219 is capable of (and this is the only module I have easy access to) so I need an external power source.

I've seen on many forum posts that the NI 9219 can't handle external voltage excitation but is this just for bridge circuits? Since I just want to measure voltage do you know if my proposed setup work? I don't want to damage the hardware.

I'm new to this area so any help would be much appreciated!

Emily