Analog data from CO2( http://rtcin.com/Product?ProductId=14 ) sensor but it's not giving in % or ppm value

Analog data from CO2( http://rtcin.com/Product?ProductId=14 ) sensor but it's not giving in % or ppm values. Please guide how to give a threshold like 5% or 50000ppm for relay operation

Is that ok?

int analogPin = A3; // potentiometer wiper (middle terminal) connected to analog pin 3
// outside leads to ground and +5V
int val = 0; // variable to store the value read

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

void loop() {
val = analogRead(analogPin); // read the input pin
Serial.println(val); // debug value
} //Relay
if(val < 5000){
digitalWrite(5, HIGH);
} else {
digitalWrite(5, LOW);
}

Topic closed pending investigation of duplicate