Pressure transducer - NI 9263 and NI 921

[gregorian7]

Hi

I am completely new with Labview  and  I'd like to connect pressure transducer with NI 9263 (excitation signal) and NI 9215 (read voltage from sensor).

Is it possible I need for work, I know that guy before me did manage to do it. I know that NI 9263 is only 1mA output. I couldn't find any information about sensor input current. There is only information about I out = 30mA.

I have attached sensor data  sheet and DAQ chassis previous configuration.

I would be appreciated  for any help.

Regards,

Gregorian

[Maestro_Sanchez]

Do you need help with a VI or are you just asking if those devices will work for your program?

[sirwin]

Why not use a bridge completion module (Like the NI-9237) which provides both excitation and output measurement?

[gregorian7]

Hi.

Thanks both for answers.

We have got a lot of hardware around , unfortunately I didn't find NI9237 (I know that would be the easiest way).

Thus I will have to work this out with hardware I have already got in place .

I have not started building VI, first I'd like to be sure if I can acquire signal from sensors with modules I have got.

If you could give any advises and suggestions regarding VI I will be more then happy. 

Thanks

[GerdW]

Hi gregorian,

Is it possible I need for work, I know that guy before me did manage to do it. I know that NI 9263 is only 1mA output. I couldn't find any information about sensor input current. There is only information about I out = 30mA.

Your sensor P2164 is described by "18-36V supply" in your datasheet: Why don't you use a simple standard 24V power supply for this sensor? All you need is to measure it's output signal using your NI9215 module…

(Btw. there is another place in your datasheet mentioning a "18-32V supply", so I guess this spec sheet needs some editing…)

[gregorian7]

Hi.

My sensor model code is P2103-0001 (25mV output, High range connector outlet, Non IS, Welded adaptor, 1/4BSP).

Does it mean that is 10VDC supply voltage?

10BAR = 25mA

Thanks

[GerdW · Accepted solution]

Hi gregorian,

why didn't you provide the model-ID in your first post?

Does it mean that is 10VDC supply voltage?

Yes and no.

Yes, you could use 10V for supply/excitation. (It's the recommended value.)

And no because you can also use any other voltage as long as you stay below 12V as mentioned in the datasheet!

10BAR = 25mA

Wrong.

10bar will give 25mV output signal when using 10V excitation voltage!

The formula will be

output := 25mV * pressure/(full range pressure) * (supply voltage)/10V

It's a simple scaling…

I still recommend to use an external power supply for your sensor as your NI9263 will not be able to drive the needed power for your sensor due to it's low resistance!

[gregorian7 · Accepted solution]

Hi.

Sorry that I didn't provide sensor information in my first post.

Thanks for your help.

[bill_gilbert · Accepted solution]

You could use an external 10V supply (12V MAX according the datasheet) to excite this 350 ohm bridge transducer. However you are only going to see approximately 20mV of signal output over the full scale range. With the 16 bit resolution of the 9215 over it's +/-10 input range you only have resolution of 0.0003 V, which will give you resolution of  1/65th of the transducer range, which is not very good. Another option would be to use an external bridge conditioner if you can find one, to excite and amplify the transducer, then use the 9215 to read that, and get the full benefit of it's resolution.

[bill_gilbert]

I should have mentioned some possible sources for these devices. NI is great, but they don't make them. All the transducer manufacturers probably have outboard bridge conditioners available. I recently used one from Interface (SGA-ACDC) for one of their load cells that is quite versatile and has both input and output switchable filtering built in. This was desirable for us, since the sensor was to be in an MRI scanner, which is an electrically noisy environment, and I was concerned about aliasing. Google for bridge signal conditioners, and you can have a lot of reading material.