0 to 15 psi pressure sensor - River height

Other Hardware Sensors
1

// I have a pressure sensor from Mouser Electronics and I would like to read the height of the river I live next to. I have a pressure // gage and a bubbler system that works ok but I would like to graph the height of the river.
// The pressure sensor I have is a gage type for 0 to 15 psi (785-SSCSNBN015PGAA5) with an output of .5 to 4.5 volts and an Arduino uno to do the graphing.
// The problem I’m having is: With no pressure applied and 5 volts to the sensor I have a voltage reading of .2 volts form the sensor. Do I offset the .2 volt to get a zero reading? If so how? Is the sensor bad?
// .5 volts analog reading = 102, 4.5 volts is an analog reading = 921, one foot of water height = .434 psi

// River water height
//Arduino uno
void setup()
{
Serial.begin(115200);
}

void loop()
{
float PSI = (Analogread(A0) -102) * 15 (921 – 102);
int RiverHeight = PSI / .434;
Serial.print( RiverHeight);
Serial.print(”River height");

}

2

Please post link to the data sheet of your sensor.

How do you measure this 0.2V output? It's lower than the minimum stated by your description (it's normal for sensors to produce a minimum voltage, which you probably simply have to deduct first: this way you can tell whether the sensor is connected in the first place).

3

If that sensor's output is as claimed, this should get you close:

float PSI = (analogRead(A0) - 102.4) / 819.2 * 15;

What is your ADC result at 0 PSI? At 15 PSI? Where did 0.2V come from?

4

Here is a good tutorial on calibrating sensors, which, if you follow instructions, takes care of the entire problem.

5

The .2 volts was measure with the sensor hooked up to 5 volts only. With a meter between ground and the output pin. Nothing hook up to the sensor ports.

Mouser 785-SSCSNBN015PGAA5

5 Volts
0 to 15 psi
.5 volts to 4.5 volts output

6

I was just wondering where 0.2V came from, with 0 pressure, the output should have been closer to 0.5V, is your meter trustworthy? What does your Arduino ADC result show at 0 pressure? Should be close to 102.