Calculating the altitude range for pressure sensor

[danielfitzgeral]

Hi, I'm looking at the MPX4115A Air pressure sensor.

I'm looking at this for a UAV application to measure barometric altitude.  I'm wanting to know what the altitude range I can measure with this is; ie:  0 -> ******   meters or feet.   

Also, if there is a better sensor option (resolution and range) with similar package size and interface, then please let me know

thanks

[TomasVaverka · Accepted solution]

Hi Daniel,

The MPX4115A is an absolute pressure sensor with an analog output. It measures the pressure on its port in relation to a vacuum sealed reference. Its pressure range is from 15kPa to 115kPa. According to the U.S. Standard Atmosphere model for altitude vs pressure, it corresponds to an altitude range from -1080m (115kPa) to 13503m (15kPa).

Regarding possible alternative parts, there is the MPXxx6115A series in smaller packages (SOP or SSOP). Main characteristics are the same.

If you did not prefer an analog output, the MPL3115A2 would be a good choice. Its calibrated pressure range is from 50kPa to 110 kPa which corresponds to an altitude range from -698m to 5572m. It allows direct altitude reading (almost no additional computing needed) over the I2C interface and provides altitude data to within 30cm (with oversampling enabled). michaelestanley published three articles about this part if you want to learn more.

I hope this helps.

Regards,

Tomas