Hat sich erledigt :))))))))))))))))))))))

Other Hardware Sensors
2

Honeywell ABP serie: https://sps.honeywell.com/us/en/products/sensing-and-iot/sensors/pressure-sensors/board-mount-pressure-sensors/basic-abp-series

ABPDANT015PGAA5:
ABP = Honeywell ABP serie
D = DIP package
AN = Single axial barbed port
T = liquid media
015PG = 0 ... 15 psi
A = analog output
A = 10% to 90% output range
5 = 5V sensor

Send the raw value to the Serial Monitor.

void setup()
{
  Serial.begin( 9600);
}

void loop()
{
  int rawADC = analogRead( A0);
  Serial.println( rawADC);

  delay( 250);
}

Can you show a photo with the flat corner of the sensor and tell what is connected to which pin ?
I think you have GND and 5V on one side, but I think that pin 1 = GND and pin 6 = 5V, so they can not be on the same side.