Problems with Reading Signal From a Omega PX409-050G5V

[kd2ac]

Hi everyone,

I am using an Omega PX409-050G5V pressure transducer (0-50 psi) to measure the pressure of a gas tank, as gas flowing into the tank.

I power the pressure transducer with a Model T-2 Blind Power supply of 15 V (Sierra Instrument Inc.).

The transducer is connected to an NI 9219 module. 

I have trouble reading the voltage signal from LabView. When I flow a gas into the tank, I don't see any increase in the pressure (or voltage). I don't know what I have done wrong.

The transducer is located at the inlet of the tank. The initial pressure of the tank is atmospheric pressure. The gas flows from a gas cylinder with pressure of 40 psig.

Could you please help me with this problem?

[mikeporter]

First, let's get LabVIEW out of the way. Can you read signal changes in MAX?

Mike...

[kd2ac]

No, I don't  see any changes in MAX as I flow gas into the tank. 

Does it mean that I have a bad connection or the pressure transducer broke?

[mikeporter]

Or you are looking at the wrong channel
Or it is hooked up wrong
Or the card is not working (have you done a self test?)

Mike...

[kd2ac]

I believe that I had the right channel.

I did the self test, and it was successful.

I have checked all the wires again and again, and confirmed it with one of my colleagues in my lab. 

That is why I am lost as why it is not working.

Khanh

[David22JRA]

Hi

Have you tried to create a task and verify the Connection Diagram tab (MAX) just to double check if everything is fine? Have you tried to use another computer?

Regards

[kd2ac]

Yes, I did. As I hook the transducer to a gas tank, the output voltage remains zero despite the tank pressure is increasing. My guess is the transducer itself is damaged.

[David22JRA]

I see. Yes, could be =( 

[johnsold]

Exactly how do you have everything connected? Where is the common/return/ground of the power supply connected? Which pins on the 9219 are connected to what? where are the wires on the PX409 connected?

Lynn

[dmsilev]

The Omega 5V transducers are 3-wire devices. You supply power (12-30 V, if memory serves) on one line, there's a return line which should be connected to ground on the power supply _and_ to a ground connector on the data acquisition board, and finally a signal line which gets connected to the analog input connection.

Does this match how your wires are arranged?