MPS20N0040D-D sensor not working properly

[osomeim]

I am using MPS20N0040D-D sensor for drowning detection application by attaching a pipe on the nozzle of the sensor. The other end of pipe is submerged in the water. Theoretically, the value of the reading should change as we submerge the pipe in water, but it remains constant value at 148 ( I am using 10 bit adc) . I am using the following circuit for the differential amplification of the data.

This is the image of the sensor

I am using a ATmega32a for ADC purposes. Is there any way in which we can check if the sensor is working or not.

Please help ASAP. Thank you in advance.

 

[ronsimpson]

https://langster1980.blogspot.com/2014/11/how-to-use-pressure-sensor-with.html
https://www.electrodragon.com/w/File:Pressure_Sensor_Breakout_Schematic.png
I do not have time now but you could look at the links and see if you can find a error.