When this sensor is used for the electronic pressure controller, when P2 = 100 kPa, the electronic pressure controller works normally; when P2 decreases from 100 kPa to 80 kPa, the output flow rate of the electronic pressure controller approaches zero, far lower than the set value. We suspect that the lower reference pressure is causing the sensor to malfunction.
Dear Yuwei,
please note, that the MPX5999D and other of our MEMS sensors were transferred to STMicroelectronics. Please contact their support. https://www.st.com/content/st_com/en/support/support-home.html
Please refer to a note below the Table 2. in the MPX5999D datasheet. The pressure applied to the port P1 must be always greater or equal to the pressure applied to the port P2.
With Best Regards,
Jozef