FlexiForce read problem

I have an Arduino Uno, and I am using a tekscanA201 flexiforce. I am trying to read analog output.
Below is the code I use to read data from flexiforce. But instead of getting values from (0-1024) I get values up to like 100.
How can I fix that problem?
Thanks

int flexiForcePin = A3; //analog pin 3

void setup(){
  Serial.begin(9600);
}

void loop(){
  int flexiForceReading = analogRead(flexiForcePin); 

  Serial.println(flexiForceReading);
  delay(100); //just here to slow down the output for easier reading
}

What value are you using for the reference resistor? You should be able to bring it down to 2k Ohms at 5V.

What op-amp are you using in the "Recommended Circuit"?