trafag pressure transmitter ouput

[sgirgin]

Hi all,

I have trafag pressure transmitter which has an output of 4-20 ma, ni usb 6229 daq and i am working in labview.Do i need another hardware for this system to measure the pressure?

Regards

[Dennis_Knutson]

Just the precision resistor across the current output since your board can only measure voltage.

[sgirgin]

i have also melles griot amplifier.if i connect sensor output to amplifier input then amplifier output to daq input, could i have an voltage value?

[Dennis_Knutson]

What sort of amplifier? I'm only familiar with their laser/optical products. Provide the data sheet. Seems expensive compared to a single resistor for under a dollar.

[sgirgin]

in pdf file, the top is mine.i am not sure whether it is useful for this kind of applications.ressistor can be a cheap option, but this amplifier is provided by lab not paid by me 🙂

[Dennis_Knutson]

Like using a sledge hammer to kill a fly.

[sgirgin]

i connect a ressistor which is 1700 ohm.how can i make the calibration?

[sgirgin]

i connect a ressistor which is 1700 ohm.how can i make the calibration?

[Dennis_Knutson]

Why would you pick that value? Do you know Ohm's law? At 20ma, you would have 34 voltss and that's way outside the range of your DAQ. A 500 ohm gives you a max of 10 volts. You just create a custom scale in MAX. Follow the directions.

[sgirgin]

this time i connect 470 ohm whis means min. voltage is 1.88 and max. voltage is 9.4

According to this values and from the datasheet of sensor its range is 0-100 bar. with lineer relation i calculated the equation y=13.3x-25

Here x is the voltage from the daq -25 is offset and y is my pressure value.But i still cannot read reasonable values.