So I am a bit confused as to how I would operate a pressure sensor whose pressure range is between 0-50 kPa because the moment I remove it from the packaging and expose it to the environment, it will experience 101 kPa (1 atm) which is outside its pressure range. At the same time I feel that the sensor would be useless if I cannot take it out of the package, so how does it not experience the 1 atm pressure entered by the atmosphere?


1 Answer 1


This sensor is a differential sensors, it does not measure absolute pressure but measures the pressure applied VS the ambiant atmospheric pressure.

Depending the package you can also have another "pipe" with a specific pressure.

From the datasheet:

Voltage Output versus Applied Differential Pressure The differential voltage output of the sensor is directly proportional to the differential pressure applied. The output voltage of the differential or gauge sensor increases with increasing pressure applied to the pressure side relative to the vacuum side. Similarly, output voltage increases as increasing vacuum is applied to the vacuum side relative to the pressure side.

Also Figure 4 on the datasheet shows the vent hole at the bottom and can see the piezo (Die) is between the pressure applied and ambiant pressure.

enter image description here

So the if you apply 120kPa and the ATM Pressure is 101kPa it will measure 19kPa.

If you want to measure the absolute atmospheric pressure, this is not the right sensor to use.

  • \$\begingroup\$ So is the output of this sensor the difference between the base voltage of the atmosphere pressure and the pressure you apply? \$\endgroup\$
    – user510
    Dec 24, 2018 at 9:28
  • \$\begingroup\$ You can check Fig. 2 of the datasheet, it shows the voltage vs the pressure differential. If you have 0 pressure differential, like you take out of the box and measure it, you have 0V output (+/- calibration offset). I did actually used the same sensor for some vacuum pump control. \$\endgroup\$
    – Damien
    Dec 24, 2018 at 10:30

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