Relation voltage-pressure in a differential pressure sensor

[raff5184]

Hi all,
I have an MPX2300DT1 differential pressure sensor
datasheet: http://www.farnell.com/datasheets/2291651.pdf?_ga=2.13963191.1020306335.1499374310-1603013215.1499374310

I am able to measure the output voltage but I don't know to which applied pressure it corresponds, how to "convert" the voltage to pressure. How do I retrieve this information from the datasheet?

Thank you

[Benta]

The datasheet is not very helpful, but as I know the Motorola/Freescale, now NXP pressure sensors well, here goes.

The output is "Ratiometric to supply voltage", meaning that you'll need to give it a precise and steady supply. The output will vary with the supply voltage otherwise.
It's specified at 6 V, so that's what you should aim for.

The key parameter is "Sensitivity", listed as 5 uV/V/mmHg.
If you enter the 6 V supply voltage into this spec, you'll get 30 uV/mmHg as the output.

The zero pressure offset is pretty wide, so you'll need a true differential amplifier after the sensor.

Hope this helps.


EDIT: the voltage you need to measure is the difference between Out+ and Out-. The absolute value of those two voltages is somewhere around half the supply voltage.

[raff5184]

The output is "Ratiometric to supply voltage", meaning that you'll need to give it a precise and steady supply. The output will vary with the supply voltage otherwise.
It's specified at 6 V, so that's what you should aim for.

I have a DC supply, so no problem

The key parameter is "Sensitivity", listed as 5 uV/V/mmHg.
If you enter the 6 V supply voltage into this spec, you'll get 30 uV/mmHg as the output.

So does it mean that an increment of 1 mmHg corresponds to an increment of 30 uV at the output?

so you'll need a true differential amplifier after the sensor.

you mean a differential amplif that amplifies the difference between Out+ and Out- otherwise it is too small to be measured?

[Benta]

So does it mean that an increment of 1 mmHg corresponds to an increment of 30 uV at the output?

You could put it like that. For every 1 mmHg de/increase in pressure, the difference between Out+ and Out- will de/increase by 30 uV linearly.

you mean a differential amplif that amplifies the difference between Out+ and Out- otherwise it is too small to be measured?

I don't know what and how you need to measure this. I was just pointing out, that microvolt signals are normally not too useful, so if you need to amplify the output voltage (= difference between Out+ and Out-), a differential amp is needed, as the absolute output voltage is undefined.